in any case.
</para>
</tip>
+
+ <para>
+ There is built-in syntax to compute a depth- or breadth-first sort column.
+ For example:
+
+<programlisting>
+WITH RECURSIVE search_tree(id, link, data) AS (
+ SELECT t.id, t.link, t.data
+ FROM tree t
+ UNION ALL
+ SELECT t.id, t.link, t.data
+ FROM tree t, search_tree st
+ WHERE t.id = st.link
+) <emphasis>SEARCH DEPTH FIRST BY id SET ordercol</emphasis>
+SELECT * FROM search_tree ORDER BY ordercol;
+
+WITH RECURSIVE search_tree(id, link, data) AS (
+ SELECT t.id, t.link, t.data
+ FROM tree t
+ UNION ALL
+ SELECT t.id, t.link, t.data
+ FROM tree t, search_tree st
+ WHERE t.id = st.link
+) <emphasis>SEARCH BREADTH FIRST BY id SET ordercol</emphasis>
+SELECT * FROM search_tree ORDER BY ordercol;
+</programlisting>
+ This syntax is internally expanded to something similar to the above
+ hand-written forms. The <literal>SEARCH</literal> clause specifies whether
+ depth- or breadth first search is wanted, the list of columns to track for
+ sorting, and a column name that will contain the result data that can be
+ used for sorting. That column will implicitly be added to the output rows
+ of the CTE.
+ </para>
</sect3>
<sect3 id="queries-with-cycle">
</para>
</tip>
+ <para>
+ There is built-in syntax to simplify cycle detection. The above query can
+ also be written like this:
+<programlisting>
+WITH RECURSIVE search_graph(id, link, data, depth) AS (
+ SELECT g.id, g.link, g.data, 1
+ FROM graph g
+ UNION ALL
+ SELECT g.id, g.link, g.data, sg.depth + 1
+ FROM graph g, search_graph sg
+ WHERE g.id = sg.link
+) <emphasis>CYCLE id SET is_cycle TO true DEFAULT false USING path</emphasis>
+SELECT * FROM search_graph;
+</programlisting>
+ and it will be internally rewritten to the above form. The
+ <literal>CYCLE</literal> clause specifies first the list of columns to
+ track for cycle detection, then a column name that will show whether a
+ cycle has been detected, then two values to use in that column for the yes
+ and no cases, and finally the name of another column that will track the
+ path. The cycle and path columns will implicitly be added to the output
+ rows of the CTE.
+ </para>
+
<tip>
<para>
The cycle path column is computed in the same way as the depth-first
- ordering column show in the previous section.
+ ordering column show in the previous section. A query can have both a
+ <literal>SEARCH</literal> and a <literal>CYCLE</literal> clause, but a
+ depth-first search specification and a cycle detection specification would
+ create redundant computations, so it's more efficient to just use the
+ <literal>CYCLE</literal> clause and order by the path column. If
+ breadth-first ordering is wanted, then specifying both
+ <literal>SEARCH</literal> and <literal>CYCLE</literal> can be useful.
</para>
</tip>
<phrase>and <replaceable class="parameter">with_query</replaceable> is:</phrase>
<replaceable class="parameter">with_query_name</replaceable> [ ( <replaceable class="parameter">column_name</replaceable> [, ...] ) ] AS [ [ NOT ] MATERIALIZED ] ( <replaceable class="parameter">select</replaceable> | <replaceable class="parameter">values</replaceable> | <replaceable class="parameter">insert</replaceable> | <replaceable class="parameter">update</replaceable> | <replaceable class="parameter">delete</replaceable> )
+ [ SEARCH { BREADTH | DEPTH } FIRST BY <replaceable>column_name</replaceable> [, ...] SET <replaceable>search_seq_col_name</replaceable> ]
+ [ CYCLE <replaceable>column_name</replaceable> [, ...] SET <replaceable>cycle_mark_col_name</replaceable> TO <replaceable>cycle_mark_value</replaceable> DEFAULT <replaceable>cycle_mark_default</replaceable> USING <replaceable>cycle_path_col_name</replaceable> ]
TABLE [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ]
</synopsis>
queries that do not use recursion or forward references.
</para>
+ <para>
+ The optional <literal>SEARCH</literal> clause computes a <firstterm>search
+ sequence column</firstterm> that can be used for ordering the results of a
+ recursive query in either breadth-first or depth-first order. The
+ supplied column name list specifies the row key that is to be used for
+ keeping track of visited rows. A column named
+ <replaceable>search_seq_col_name</replaceable> will be added to the result
+ column list of the <literal>WITH</literal> query. This column can be
+ ordered by in the outer query to achieve the respective ordering. See
+ <xref linkend="queries-with-search"/> for examples.
+ </para>
+
+ <para>
+ The optional <literal>CYCLE</literal> clause is used to detect cycles in
+ recursive queries. The supplied column name list specifies the row key
+ that is to be used for keeping track of visited rows. A column named
+ <replaceable>cycle_mark_col_name</replaceable> will be added to the result
+ column list of the <literal>WITH</literal> query. This column will be set
+ to <replaceable>cycle_mark_value</replaceable> when a cycle has been
+ detected, else to <replaceable>cycle_mark_default</replaceable>.
+ Furthermore, processing of the recursive union will stop when a cycle has
+ been detected. <replaceable>cycle_mark_value</replaceable> and
+ <replaceable>cycle_mark_default</replaceable> must be constants and they
+ must be coercible to a common data type, and the data type must have an
+ inequality operator. (The SQL standard requires that they be character
+ strings, but PostgreSQL does not require that.) Furthermore, a column
+ named <replaceable>cycle_path_col_name</replaceable> will be added to the
+ result column list of the <literal>WITH</literal> query. This column is
+ used internally for tracking visited rows. See <xref
+ linkend="queries-with-cycle"/> for examples.
+ </para>
+
+ <para>
+ Both the <literal>SEARCH</literal> and the <literal>CYCLE</literal> clause
+ are only valid for recursive <literal>WITH</literal> queries. The
+ <replaceable>with_query</replaceable> must be a <literal>UNION</literal>
+ (or <literal>UNION ALL</literal>) of two <literal>SELECT</literal> (or
+ equivalent) commands (no nested <literal>UNION</literal>s). If both
+ clauses are used, the column added by the <literal>SEARCH</literal> clause
+ appears before the columns added by the <literal>CYCLE</literal> clause.
+ </para>
+
<para>
The primary query and the <literal>WITH</literal> queries are all
(notionally) executed at the same time. This implies that the effects of
context->addrs);
/* fall through to examine substructure */
}
+ else if (IsA(node, CTECycleClause))
+ {
+ CTECycleClause *cc = (CTECycleClause *) node;
+
+ if (OidIsValid(cc->cycle_mark_type))
+ add_object_address(OCLASS_TYPE, cc->cycle_mark_type, 0,
+ context->addrs);
+ if (OidIsValid(cc->cycle_mark_collation))
+ add_object_address(OCLASS_COLLATION, cc->cycle_mark_collation, 0,
+ context->addrs);
+ if (OidIsValid(cc->cycle_mark_neop))
+ add_object_address(OCLASS_OPERATOR, cc->cycle_mark_neop, 0,
+ context->addrs);
+ /* fall through to examine substructure */
+ }
else if (IsA(node, Query))
{
/* Recurse into RTE subquery or not-yet-planned sublink subquery */
return newnode;
}
+static CTESearchClause *
+_copyCTESearchClause(const CTESearchClause *from)
+{
+ CTESearchClause *newnode = makeNode(CTESearchClause);
+
+ COPY_NODE_FIELD(search_col_list);
+ COPY_SCALAR_FIELD(search_breadth_first);
+ COPY_STRING_FIELD(search_seq_column);
+ COPY_LOCATION_FIELD(location);
+
+ return newnode;
+}
+
+static CTECycleClause *
+_copyCTECycleClause(const CTECycleClause *from)
+{
+ CTECycleClause *newnode = makeNode(CTECycleClause);
+
+ COPY_NODE_FIELD(cycle_col_list);
+ COPY_STRING_FIELD(cycle_mark_column);
+ COPY_NODE_FIELD(cycle_mark_value);
+ COPY_NODE_FIELD(cycle_mark_default);
+ COPY_STRING_FIELD(cycle_path_column);
+ COPY_LOCATION_FIELD(location);
+ COPY_SCALAR_FIELD(cycle_mark_type);
+ COPY_SCALAR_FIELD(cycle_mark_typmod);
+ COPY_SCALAR_FIELD(cycle_mark_collation);
+ COPY_SCALAR_FIELD(cycle_mark_neop);
+
+ return newnode;
+}
+
static CommonTableExpr *
_copyCommonTableExpr(const CommonTableExpr *from)
{
COPY_NODE_FIELD(aliascolnames);
COPY_SCALAR_FIELD(ctematerialized);
COPY_NODE_FIELD(ctequery);
+ COPY_NODE_FIELD(search_clause);
+ COPY_NODE_FIELD(cycle_clause);
COPY_LOCATION_FIELD(location);
COPY_SCALAR_FIELD(cterecursive);
COPY_SCALAR_FIELD(cterefcount);
case T_OnConflictClause:
retval = _copyOnConflictClause(from);
break;
+ case T_CTESearchClause:
+ retval = _copyCTESearchClause(from);
+ break;
+ case T_CTECycleClause:
+ retval = _copyCTECycleClause(from);
+ break;
case T_CommonTableExpr:
retval = _copyCommonTableExpr(from);
break;
return true;
}
+static bool
+_equalCTESearchClause(const CTESearchClause *a, const CTESearchClause *b)
+{
+ COMPARE_NODE_FIELD(search_col_list);
+ COMPARE_SCALAR_FIELD(search_breadth_first);
+ COMPARE_STRING_FIELD(search_seq_column);
+ COMPARE_LOCATION_FIELD(location);
+
+ return true;
+}
+
+static bool
+_equalCTECycleClause(const CTECycleClause *a, const CTECycleClause *b)
+{
+ COMPARE_NODE_FIELD(cycle_col_list);
+ COMPARE_STRING_FIELD(cycle_mark_column);
+ COMPARE_NODE_FIELD(cycle_mark_value);
+ COMPARE_NODE_FIELD(cycle_mark_default);
+ COMPARE_STRING_FIELD(cycle_path_column);
+ COMPARE_LOCATION_FIELD(location);
+ COMPARE_SCALAR_FIELD(cycle_mark_type);
+ COMPARE_SCALAR_FIELD(cycle_mark_typmod);
+ COMPARE_SCALAR_FIELD(cycle_mark_collation);
+ COMPARE_SCALAR_FIELD(cycle_mark_neop);
+
+ return true;
+}
+
static bool
_equalCommonTableExpr(const CommonTableExpr *a, const CommonTableExpr *b)
{
COMPARE_NODE_FIELD(aliascolnames);
COMPARE_SCALAR_FIELD(ctematerialized);
COMPARE_NODE_FIELD(ctequery);
+ COMPARE_NODE_FIELD(search_clause);
+ COMPARE_NODE_FIELD(cycle_clause);
COMPARE_LOCATION_FIELD(location);
COMPARE_SCALAR_FIELD(cterecursive);
COMPARE_SCALAR_FIELD(cterefcount);
case T_OnConflictClause:
retval = _equalOnConflictClause(a, b);
break;
+ case T_CTESearchClause:
+ retval = _equalCTESearchClause(a, b);
+ break;
+ case T_CTECycleClause:
+ retval = _equalCTECycleClause(a, b);
+ break;
case T_CommonTableExpr:
retval = _equalCommonTableExpr(a, b);
break;
case T_OnConflictClause:
loc = ((const OnConflictClause *) expr)->location;
break;
+ case T_CTESearchClause:
+ loc = ((const CTESearchClause *) expr)->location;
+ break;
+ case T_CTECycleClause:
+ loc = ((const CTECycleClause *) expr)->location;
+ break;
case T_CommonTableExpr:
loc = ((const CommonTableExpr *) expr)->location;
break;
case T_NextValueExpr:
case T_RangeTblRef:
case T_SortGroupClause:
+ case T_CTESearchClause:
/* primitive node types with no expression subnodes */
break;
case T_WithCheckOption:
return true;
}
break;
+ case T_CTECycleClause:
+ {
+ CTECycleClause *cc = (CTECycleClause *) node;
+
+ if (walker(cc->cycle_mark_value, context))
+ return true;
+ if (walker(cc->cycle_mark_default, context))
+ return true;
+ }
+ break;
case T_CommonTableExpr:
{
CommonTableExpr *cte = (CommonTableExpr *) node;
* Invoke the walker on the CTE's Query node, so it can
* recurse into the sub-query if it wants to.
*/
- return walker(cte->ctequery, context);
+ if (walker(cte->ctequery, context))
+ return true;
+
+ if (walker(cte->search_clause, context))
+ return true;
+ if (walker(cte->cycle_clause, context))
+ return true;
}
break;
case T_List:
case T_NextValueExpr:
case T_RangeTblRef:
case T_SortGroupClause:
+ case T_CTESearchClause:
return (Node *) copyObject(node);
case T_WithCheckOption:
{
return (Node *) newnode;
}
break;
+ case T_CTECycleClause:
+ {
+ CTECycleClause *cc = (CTECycleClause *) node;
+ CTECycleClause *newnode;
+
+ FLATCOPY(newnode, cc, CTECycleClause);
+ MUTATE(newnode->cycle_mark_value, cc->cycle_mark_value, Node *);
+ MUTATE(newnode->cycle_mark_default, cc->cycle_mark_default, Node *);
+ return (Node *) newnode;
+ }
+ break;
case T_CommonTableExpr:
{
CommonTableExpr *cte = (CommonTableExpr *) node;
* recurse into the sub-query if it wants to.
*/
MUTATE(newnode->ctequery, cte->ctequery, Node *);
+
+ MUTATE(newnode->search_clause, cte->search_clause, CTESearchClause *);
+ MUTATE(newnode->cycle_clause, cte->cycle_clause, CTECycleClause *);
+
return (Node *) newnode;
}
break;
}
break;
case T_CommonTableExpr:
+ /* search_clause and cycle_clause are not interesting here */
return walker(((CommonTableExpr *) node)->ctequery, context);
default:
elog(ERROR, "unrecognized node type: %d",
WRITE_LOCATION_FIELD(location);
}
+static void
+_outCTESearchClause(StringInfo str, const CTESearchClause *node)
+{
+ WRITE_NODE_TYPE("CTESEARCHCLAUSE");
+
+ WRITE_NODE_FIELD(search_col_list);
+ WRITE_BOOL_FIELD(search_breadth_first);
+ WRITE_STRING_FIELD(search_seq_column);
+ WRITE_LOCATION_FIELD(location);
+}
+
+static void
+_outCTECycleClause(StringInfo str, const CTECycleClause *node)
+{
+ WRITE_NODE_TYPE("CTECYCLECLAUSE");
+
+ WRITE_NODE_FIELD(cycle_col_list);
+ WRITE_STRING_FIELD(cycle_mark_column);
+ WRITE_NODE_FIELD(cycle_mark_value);
+ WRITE_NODE_FIELD(cycle_mark_default);
+ WRITE_STRING_FIELD(cycle_path_column);
+ WRITE_LOCATION_FIELD(location);
+ WRITE_OID_FIELD(cycle_mark_type);
+ WRITE_INT_FIELD(cycle_mark_typmod);
+ WRITE_OID_FIELD(cycle_mark_collation);
+ WRITE_OID_FIELD(cycle_mark_neop);
+}
+
static void
_outCommonTableExpr(StringInfo str, const CommonTableExpr *node)
{
WRITE_NODE_FIELD(aliascolnames);
WRITE_ENUM_FIELD(ctematerialized, CTEMaterialize);
WRITE_NODE_FIELD(ctequery);
+ WRITE_NODE_FIELD(search_clause);
+ WRITE_NODE_FIELD(cycle_clause);
WRITE_LOCATION_FIELD(location);
WRITE_BOOL_FIELD(cterecursive);
WRITE_INT_FIELD(cterefcount);
case T_WithClause:
_outWithClause(str, obj);
break;
+ case T_CTESearchClause:
+ _outCTESearchClause(str, obj);
+ break;
+ case T_CTECycleClause:
+ _outCTECycleClause(str, obj);
+ break;
case T_CommonTableExpr:
_outCommonTableExpr(str, obj);
break;
READ_DONE();
}
+/*
+ * _readCTESearchClause
+ */
+static CTESearchClause *
+_readCTESearchClause(void)
+{
+ READ_LOCALS(CTESearchClause);
+
+ READ_NODE_FIELD(search_col_list);
+ READ_BOOL_FIELD(search_breadth_first);
+ READ_STRING_FIELD(search_seq_column);
+ READ_LOCATION_FIELD(location);
+
+ READ_DONE();
+}
+
+/*
+ * _readCTECycleClause
+ */
+static CTECycleClause *
+_readCTECycleClause(void)
+{
+ READ_LOCALS(CTECycleClause);
+
+ READ_NODE_FIELD(cycle_col_list);
+ READ_STRING_FIELD(cycle_mark_column);
+ READ_NODE_FIELD(cycle_mark_value);
+ READ_NODE_FIELD(cycle_mark_default);
+ READ_STRING_FIELD(cycle_path_column);
+ READ_LOCATION_FIELD(location);
+ READ_OID_FIELD(cycle_mark_type);
+ READ_INT_FIELD(cycle_mark_typmod);
+ READ_OID_FIELD(cycle_mark_collation);
+ READ_OID_FIELD(cycle_mark_neop);
+
+ READ_DONE();
+}
+
/*
* _readCommonTableExpr
*/
READ_NODE_FIELD(aliascolnames);
READ_ENUM_FIELD(ctematerialized, CTEMaterialize);
READ_NODE_FIELD(ctequery);
+ READ_NODE_FIELD(search_clause);
+ READ_NODE_FIELD(cycle_clause);
READ_LOCATION_FIELD(location);
READ_BOOL_FIELD(cterecursive);
READ_INT_FIELD(cterefcount);
return_value = _readWindowClause();
else if (MATCH("ROWMARKCLAUSE", 13))
return_value = _readRowMarkClause();
+ else if (MATCH("CTESEARCHCLAUSE", 15))
+ return_value = _readCTESearchClause();
+ else if (MATCH("CTECYCLECLAUSE", 14))
+ return_value = _readCTECycleClause();
else if (MATCH("COMMONTABLEEXPR", 15))
return_value = _readCommonTableExpr();
else if (MATCH("SETOPERATIONSTMT", 16))
return qry;
}
+/*
+ * Make a SortGroupClause node for a SetOperationStmt's groupClauses
+ */
+SortGroupClause *
+makeSortGroupClauseForSetOp(Oid rescoltype)
+{
+ SortGroupClause *grpcl = makeNode(SortGroupClause);
+ Oid sortop;
+ Oid eqop;
+ bool hashable;
+
+ /* determine the eqop and optional sortop */
+ get_sort_group_operators(rescoltype,
+ false, true, false,
+ &sortop, &eqop, NULL,
+ &hashable);
+
+ /* we don't have a tlist yet, so can't assign sortgrouprefs */
+ grpcl->tleSortGroupRef = 0;
+ grpcl->eqop = eqop;
+ grpcl->sortop = sortop;
+ grpcl->nulls_first = false; /* OK with or without sortop */
+ grpcl->hashable = hashable;
+
+ return grpcl;
+}
+
/*
* transformSetOperationTree
* Recursively transform leaves and internal nodes of a set-op tree
*/
if (op->op != SETOP_UNION || !op->all)
{
- SortGroupClause *grpcl = makeNode(SortGroupClause);
- Oid sortop;
- Oid eqop;
- bool hashable;
ParseCallbackState pcbstate;
setup_parser_errposition_callback(&pcbstate, pstate,
bestlocation);
- /* determine the eqop and optional sortop */
- get_sort_group_operators(rescoltype,
- false, true, false,
- &sortop, &eqop, NULL,
- &hashable);
+ op->groupClauses = lappend(op->groupClauses,
+ makeSortGroupClauseForSetOp(rescoltype));
cancel_parser_errposition_callback(&pcbstate);
-
- /* we don't have a tlist yet, so can't assign sortgrouprefs */
- grpcl->tleSortGroupRef = 0;
- grpcl->eqop = eqop;
- grpcl->sortop = sortop;
- grpcl->nulls_first = false; /* OK with or without sortop */
- grpcl->hashable = hashable;
-
- op->groupClauses = lappend(op->groupClauses, grpcl);
}
/*
%type <list> row explicit_row implicit_row type_list array_expr_list
%type <node> case_expr case_arg when_clause case_default
%type <list> when_clause_list
+%type <node> opt_search_clause opt_cycle_clause
%type <ival> sub_type opt_materialized
%type <value> NumericOnly
%type <list> NumericOnly_list
ASSERTION ASSIGNMENT ASYMMETRIC AT ATTACH ATTRIBUTE AUTHORIZATION
BACKWARD BEFORE BEGIN_P BETWEEN BIGINT BINARY BIT
- BOOLEAN_P BOTH BY
+ BOOLEAN_P BOTH BREADTH BY
CACHE CALL CALLED CASCADE CASCADED CASE CAST CATALOG_P CHAIN CHAR_P
CHARACTER CHARACTERISTICS CHECK CHECKPOINT CLASS CLOSE
CURRENT_TIME CURRENT_TIMESTAMP CURRENT_USER CURSOR CYCLE
DATA_P DATABASE DAY_P DEALLOCATE DEC DECIMAL_P DECLARE DEFAULT DEFAULTS
- DEFERRABLE DEFERRED DEFINER DELETE_P DELIMITER DELIMITERS DEPENDS DESC
+ DEFERRABLE DEFERRED DEFINER DELETE_P DELIMITER DELIMITERS DEPENDS DEPTH DESC
DETACH DICTIONARY DISABLE_P DISCARD DISTINCT DO DOCUMENT_P DOMAIN_P
DOUBLE_P DROP
* WITH [ RECURSIVE ] <query name> [ (<column>,...) ]
* AS (query) [ SEARCH or CYCLE clause ]
*
- * We don't currently support the SEARCH or CYCLE clause.
- *
* Recognizing WITH_LA here allows a CTE to be named TIME or ORDINALITY.
*/
with_clause:
| cte_list ',' common_table_expr { $$ = lappend($1, $3); }
;
-common_table_expr: name opt_name_list AS opt_materialized '(' PreparableStmt ')'
+common_table_expr: name opt_name_list AS opt_materialized '(' PreparableStmt ')' opt_search_clause opt_cycle_clause
{
CommonTableExpr *n = makeNode(CommonTableExpr);
n->ctename = $1;
n->aliascolnames = $2;
n->ctematerialized = $4;
n->ctequery = $6;
+ n->search_clause = castNode(CTESearchClause, $8);
+ n->cycle_clause = castNode(CTECycleClause, $9);
n->location = @1;
$$ = (Node *) n;
}
| /*EMPTY*/ { $$ = CTEMaterializeDefault; }
;
+opt_search_clause:
+ SEARCH DEPTH FIRST_P BY columnList SET ColId
+ {
+ CTESearchClause *n = makeNode(CTESearchClause);
+ n->search_col_list = $5;
+ n->search_breadth_first = false;
+ n->search_seq_column = $7;
+ n->location = @1;
+ $$ = (Node *) n;
+ }
+ | SEARCH BREADTH FIRST_P BY columnList SET ColId
+ {
+ CTESearchClause *n = makeNode(CTESearchClause);
+ n->search_col_list = $5;
+ n->search_breadth_first = true;
+ n->search_seq_column = $7;
+ n->location = @1;
+ $$ = (Node *) n;
+ }
+ | /*EMPTY*/
+ {
+ $$ = NULL;
+ }
+ ;
+
+opt_cycle_clause:
+ CYCLE columnList SET ColId TO AexprConst DEFAULT AexprConst USING ColId
+ {
+ CTECycleClause *n = makeNode(CTECycleClause);
+ n->cycle_col_list = $2;
+ n->cycle_mark_column = $4;
+ n->cycle_mark_value = $6;
+ n->cycle_mark_default = $8;
+ n->cycle_path_column = $10;
+ n->location = @1;
+ $$ = (Node *) n;
+ }
+ | /*EMPTY*/
+ {
+ $$ = NULL;
+ }
+ ;
+
opt_with_clause:
with_clause { $$ = $1; }
| /*EMPTY*/ { $$ = NULL; }
| BACKWARD
| BEFORE
| BEGIN_P
+ | BREADTH
| BY
| CACHE
| CALL
| DELIMITER
| DELIMITERS
| DEPENDS
+ | DEPTH
| DETACH
| DICTIONARY
| DISABLE_P
| BIT
| BOOLEAN_P
| BOTH
+ | BREADTH
| BY
| CACHE
| CALL
| DELIMITER
| DELIMITERS
| DEPENDS
+ | DEPTH
| DESC
| DETACH
| DICTIONARY
break;
+ case EXPR_KIND_CYCLE_MARK:
+ errkind = true;
+ break;
+
/*
* There is intentionally no default: case here, so that the
* compiler will warn if we add a new ParseExprKind without
case EXPR_KIND_GENERATED_COLUMN:
err = _("window functions are not allowed in column generation expressions");
break;
+ case EXPR_KIND_CYCLE_MARK:
+ errkind = true;
+ break;
/*
* There is intentionally no default: case here, so that the
#include "catalog/pg_type.h"
#include "nodes/nodeFuncs.h"
#include "parser/analyze.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_collate.h"
#include "parser/parse_cte.h"
+#include "parser/parse_expr.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
+#include "utils/typcache.h"
/* Enumeration of contexts in which a self-reference is disallowed */
if (lctyp != NULL || lctypmod != NULL || lccoll != NULL) /* shouldn't happen */
elog(ERROR, "wrong number of output columns in WITH");
}
+
+ if (cte->search_clause || cte->cycle_clause)
+ {
+ Query *ctequery;
+ SetOperationStmt *sos;
+
+ if (!cte->cterecursive)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("WITH query is not recursive"),
+ parser_errposition(pstate, cte->location)));
+
+ /*
+ * SQL requires a WITH list element (CTE) to be "expandable" in order
+ * to allow a search or cycle clause. That is a stronger requirement
+ * than just being recursive. It basically means the query expression
+ * looks like
+ *
+ * non-recursive query UNION [ALL] recursive query
+ *
+ * and that the recursive query is not itself a set operation.
+ *
+ * As of this writing, most of these criteria are already satisfied by
+ * all recursive CTEs allowed by PostgreSQL. In the future, if
+ * further variants recursive CTEs are accepted, there might be
+ * further checks required here to determine what is "expandable".
+ */
+
+ ctequery = castNode(Query, cte->ctequery);
+ Assert(ctequery->setOperations);
+ sos = castNode(SetOperationStmt, ctequery->setOperations);
+
+ /*
+ * This left side check is not required for expandability, but
+ * rewriteSearchAndCycle() doesn't currently have support for it, so
+ * we catch it here.
+ */
+ if (!IsA(sos->larg, RangeTblRef))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("with a SEARCH or CYCLE clause, the left side of the UNION must be a SELECT")));
+
+ if (!IsA(sos->rarg, RangeTblRef))
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("with a SEARCH or CYCLE clause, the right side of the UNION must be a SELECT")));
+ }
+
+ if (cte->search_clause)
+ {
+ ListCell *lc;
+ List *seen = NIL;
+
+ foreach(lc, cte->search_clause->search_col_list)
+ {
+ Value *colname = lfirst(lc);
+
+ if (!list_member(cte->ctecolnames, colname))
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("search column \"%s\" not in WITH query column list",
+ strVal(colname)),
+ parser_errposition(pstate, cte->search_clause->location)));
+
+ if (list_member(seen, colname))
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_COLUMN),
+ errmsg("search column \"%s\" specified more than once",
+ strVal(colname)),
+ parser_errposition(pstate, cte->search_clause->location)));
+ seen = lappend(seen, colname);
+ }
+
+ if (list_member(cte->ctecolnames, makeString(cte->search_clause->search_seq_column)))
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("search sequence column name \"%s\" already used in WITH query column list",
+ cte->search_clause->search_seq_column),
+ parser_errposition(pstate, cte->search_clause->location));
+ }
+
+ if (cte->cycle_clause)
+ {
+ ListCell *lc;
+ List *seen = NIL;
+ TypeCacheEntry *typentry;
+ Oid op;
+
+ foreach(lc, cte->cycle_clause->cycle_col_list)
+ {
+ Value *colname = lfirst(lc);
+
+ if (!list_member(cte->ctecolnames, colname))
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("cycle column \"%s\" not in WITH query column list",
+ strVal(colname)),
+ parser_errposition(pstate, cte->cycle_clause->location)));
+
+ if (list_member(seen, colname))
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_COLUMN),
+ errmsg("cycle column \"%s\" specified more than once",
+ strVal(colname)),
+ parser_errposition(pstate, cte->cycle_clause->location)));
+ seen = lappend(seen, colname);
+ }
+
+ if (list_member(cte->ctecolnames, makeString(cte->cycle_clause->cycle_mark_column)))
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("cycle mark column name \"%s\" already used in WITH query column list",
+ cte->cycle_clause->cycle_mark_column),
+ parser_errposition(pstate, cte->cycle_clause->location));
+
+ cte->cycle_clause->cycle_mark_value = transformExpr(pstate, cte->cycle_clause->cycle_mark_value,
+ EXPR_KIND_CYCLE_MARK);
+ cte->cycle_clause->cycle_mark_default = transformExpr(pstate, cte->cycle_clause->cycle_mark_default,
+ EXPR_KIND_CYCLE_MARK);
+
+ if (list_member(cte->ctecolnames, makeString(cte->cycle_clause->cycle_path_column)))
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("cycle path column name \"%s\" already used in WITH query column list",
+ cte->cycle_clause->cycle_path_column),
+ parser_errposition(pstate, cte->cycle_clause->location));
+
+ if (strcmp(cte->cycle_clause->cycle_mark_column,
+ cte->cycle_clause->cycle_path_column) == 0)
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("cycle mark column name and cycle path column name are the same"),
+ parser_errposition(pstate, cte->cycle_clause->location));
+
+ cte->cycle_clause->cycle_mark_type = select_common_type(pstate,
+ list_make2(cte->cycle_clause->cycle_mark_value,
+ cte->cycle_clause->cycle_mark_default),
+ "CYCLE", NULL);
+ cte->cycle_clause->cycle_mark_value = coerce_to_common_type(pstate,
+ cte->cycle_clause->cycle_mark_value,
+ cte->cycle_clause->cycle_mark_type,
+ "CYCLE/SET/TO");
+ cte->cycle_clause->cycle_mark_default = coerce_to_common_type(pstate,
+ cte->cycle_clause->cycle_mark_default,
+ cte->cycle_clause->cycle_mark_type,
+ "CYCLE/SET/DEFAULT");
+
+ cte->cycle_clause->cycle_mark_typmod = select_common_typmod(pstate,
+ list_make2(cte->cycle_clause->cycle_mark_value,
+ cte->cycle_clause->cycle_mark_default),
+ cte->cycle_clause->cycle_mark_type);
+
+ cte->cycle_clause->cycle_mark_collation = select_common_collation(pstate,
+ list_make2(cte->cycle_clause->cycle_mark_value,
+ cte->cycle_clause->cycle_mark_default),
+ true);
+
+ typentry = lookup_type_cache(cte->cycle_clause->cycle_mark_type, TYPECACHE_EQ_OPR);
+ if (!typentry->eq_opr)
+ ereport(ERROR,
+ errcode(ERRCODE_UNDEFINED_FUNCTION),
+ errmsg("could not identify an equality operator for type %s",
+ format_type_be(cte->cycle_clause->cycle_mark_type)));
+ op = get_negator(typentry->eq_opr);
+ if (!op)
+ ereport(ERROR,
+ errcode(ERRCODE_UNDEFINED_FUNCTION),
+ errmsg("could not identify an inequality operator for type %s",
+ format_type_be(cte->cycle_clause->cycle_mark_type)));
+
+ cte->cycle_clause->cycle_mark_neop = op;
+ }
+
+ if (cte->search_clause && cte->cycle_clause)
+ {
+ if (strcmp(cte->search_clause->search_seq_column,
+ cte->cycle_clause->cycle_mark_column) == 0)
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("search sequence column name and cycle mark column name are the same"),
+ parser_errposition(pstate, cte->search_clause->location));
+
+ if (strcmp(cte->search_clause->search_seq_column,
+ cte->cycle_clause->cycle_path_column) == 0)
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("search_sequence column name and cycle path column name are the same"),
+ parser_errposition(pstate, cte->search_clause->location));
+ }
}
/*
case EXPR_KIND_CALL_ARGUMENT:
case EXPR_KIND_COPY_WHERE:
case EXPR_KIND_GENERATED_COLUMN:
+ case EXPR_KIND_CYCLE_MARK:
/* okay */
break;
case EXPR_KIND_RETURNING:
case EXPR_KIND_VALUES:
case EXPR_KIND_VALUES_SINGLE:
+ case EXPR_KIND_CYCLE_MARK:
/* okay */
break;
case EXPR_KIND_CHECK_CONSTRAINT:
return "WHERE";
case EXPR_KIND_GENERATED_COLUMN:
return "GENERATED AS";
+ case EXPR_KIND_CYCLE_MARK:
+ return "CYCLE";
/*
* There is intentionally no default: case here, so that the
case EXPR_KIND_GENERATED_COLUMN:
err = _("set-returning functions are not allowed in column generation expressions");
break;
+ case EXPR_KIND_CYCLE_MARK:
+ errkind = true;
+ break;
/*
* There is intentionally no default: case here, so that the
int numaliases;
int varattno;
ListCell *lc;
+ int n_dontexpand_columns = 0;
+ ParseNamespaceItem *psi;
Assert(pstate != NULL);
parser_errposition(pstate, rv->location)));
}
- rte->coltypes = cte->ctecoltypes;
- rte->coltypmods = cte->ctecoltypmods;
- rte->colcollations = cte->ctecolcollations;
+ rte->coltypes = list_copy(cte->ctecoltypes);
+ rte->coltypmods = list_copy(cte->ctecoltypmods);
+ rte->colcollations = list_copy(cte->ctecolcollations);
rte->alias = alias;
if (alias)
rte->eref = eref;
+ if (cte->search_clause)
+ {
+ rte->eref->colnames = lappend(rte->eref->colnames, makeString(cte->search_clause->search_seq_column));
+ if (cte->search_clause->search_breadth_first)
+ rte->coltypes = lappend_oid(rte->coltypes, RECORDOID);
+ else
+ rte->coltypes = lappend_oid(rte->coltypes, RECORDARRAYOID);
+ rte->coltypmods = lappend_int(rte->coltypmods, -1);
+ rte->colcollations = lappend_oid(rte->colcollations, InvalidOid);
+
+ n_dontexpand_columns += 1;
+ }
+
+ if (cte->cycle_clause)
+ {
+ rte->eref->colnames = lappend(rte->eref->colnames, makeString(cte->cycle_clause->cycle_mark_column));
+ rte->coltypes = lappend_oid(rte->coltypes, cte->cycle_clause->cycle_mark_type);
+ rte->coltypmods = lappend_int(rte->coltypmods, cte->cycle_clause->cycle_mark_typmod);
+ rte->colcollations = lappend_oid(rte->colcollations, cte->cycle_clause->cycle_mark_collation);
+
+ rte->eref->colnames = lappend(rte->eref->colnames, makeString(cte->cycle_clause->cycle_path_column));
+ rte->coltypes = lappend_oid(rte->coltypes, RECORDARRAYOID);
+ rte->coltypmods = lappend_int(rte->coltypmods, -1);
+ rte->colcollations = lappend_oid(rte->colcollations, InvalidOid);
+
+ n_dontexpand_columns += 2;
+ }
+
/*
* Set flags and access permissions.
*
* Build a ParseNamespaceItem, but don't add it to the pstate's namespace
* list --- caller must do that if appropriate.
*/
- return buildNSItemFromLists(rte, list_length(pstate->p_rtable),
+ psi = buildNSItemFromLists(rte, list_length(pstate->p_rtable),
rte->coltypes, rte->coltypmods,
rte->colcollations);
+
+ /*
+ * The columns added by search and cycle clauses are not included in star
+ * expansion in queries contained in the CTE.
+ */
+ if (rte->ctelevelsup > 0)
+ for (int i = 0; i < n_dontexpand_columns; i++)
+ psi->p_nscolumns[list_length(psi->p_rte->eref->colnames) - 1 - i].p_dontexpand = true;
+
+ return psi;
}
/*
const char *colname = strVal(colnameval);
ParseNamespaceColumn *nscol = nsitem->p_nscolumns + colindex;
- if (colname[0])
+ if (nscol->p_dontexpand)
+ {
+ /* skip */
+ }
+ else if (colname[0])
{
Var *var;
{
CommonTableExpr *cte = GetCTEForRTE(pstate, rte, netlevelsup);
TargetEntry *ste;
+ List *tl = GetCTETargetList(cte);
+ int extra_cols = 0;
+
+ /*
+ * RTE for CTE will already have the search and cycle columns
+ * added, but the subquery won't, so skip looking those up.
+ */
+ if (cte->search_clause)
+ extra_cols += 1;
+ if (cte->cycle_clause)
+ extra_cols += 2;
+ if (extra_cols &&
+ attnum > list_length(tl) &&
+ attnum <= list_length(tl) + extra_cols)
+ break;
- ste = get_tle_by_resno(GetCTETargetList(cte), attnum);
+ ste = get_tle_by_resno(tl, attnum);
if (ste == NULL || ste->resjunk)
elog(ERROR, "CTE %s does not have attribute %d",
rte->eref->aliasname, attnum);
rewriteHandler.o \
rewriteManip.o \
rewriteRemove.o \
+ rewriteSearchCycle.o \
rewriteSupport.o \
rowsecurity.o
#include "rewrite/rewriteDefine.h"
#include "rewrite/rewriteHandler.h"
#include "rewrite/rewriteManip.h"
+#include "rewrite/rewriteSearchCycle.h"
#include "rewrite/rowsecurity.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
int rt_index;
ListCell *lc;
+ /*
+ * Expand SEARCH and CYCLE clauses in CTEs.
+ *
+ * This is just a convenient place to do this, since we are already
+ * looking at each Query.
+ */
+ foreach(lc, parsetree->cteList)
+ {
+ CommonTableExpr *cte = lfirst_node(CommonTableExpr, lc);
+
+ if (cte->search_clause || cte->cycle_clause)
+ {
+ cte = rewriteSearchAndCycle(cte);
+ lfirst(lc) = cte;
+ }
+ }
+
/*
* don't try to convert this into a foreach loop, because rtable list can
* get changed each time through...
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * rewriteSearchCycle.c
+ * Support for rewriting SEARCH and CYCLE clauses.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/rewrite/rewriteSearchCycle.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/pg_operator_d.h"
+#include "catalog/pg_type_d.h"
+#include "nodes/makefuncs.h"
+#include "nodes/pg_list.h"
+#include "nodes/parsenodes.h"
+#include "nodes/primnodes.h"
+#include "parser/analyze.h"
+#include "parser/parsetree.h"
+#include "rewrite/rewriteManip.h"
+#include "rewrite/rewriteSearchCycle.h"
+#include "utils/fmgroids.h"
+
+
+/*----------
+ * Rewrite a CTE with SEARCH or CYCLE clause
+ *
+ * Consider a CTE like
+ *
+ * WITH RECURSIVE ctename (col1, col2, col3) AS (
+ * query1
+ * UNION [ALL]
+ * SELECT trosl FROM ctename
+ * )
+ *
+ * With a search clause
+ *
+ * SEARCH BREADTH FIRST BY col1, col2 SET sqc
+ *
+ * the CTE is rewritten to
+ *
+ * WITH RECURSIVE ctename (col1, col2, col3, sqc) AS (
+ * SELECT col1, col2, col3, -- original WITH column list
+ * ROW(0, col1, col2) -- initial row of search columns
+ * FROM (query1) "*TLOCRN*" (col1, col2, col3)
+ * UNION [ALL]
+ * SELECT col1, col2, col3, -- same as above
+ * ROW(sqc.depth + 1, col1, col2) -- count depth
+ * FROM (SELECT trosl, ctename.sqc FROM ctename) "*TROCRN*" (col1, col2, col3, sqc)
+ * )
+ *
+ * (This isn't quite legal SQL: sqc.depth is meant to refer to the first
+ * column of sqc, which has a row type, but the field names are not defined
+ * here. Representing this properly in SQL would be more complicated (and the
+ * SQL standard actually does it in that more complicated way), but the
+ * internal representation allows us to construct it this way.)
+ *
+ * With a search caluse
+ *
+ * SEARCH DEPTH FIRST BY col1, col2 SET sqc
+ *
+ * the CTE is rewritten to
+ *
+ * WITH RECURSIVE ctename (col1, col2, col3, sqc) AS (
+ * SELECT col1, col2, col3, -- original WITH column list
+ * ARRAY[ROW(col1, col2)] -- initial row of search columns
+ * FROM (query1) "*TLOCRN*" (col1, col2, col3)
+ * UNION [ALL]
+ * SELECT col1, col2, col3, -- same as above
+ * sqc || ARRAY[ROW(col1, col2)] -- record rows seen
+ * FROM (SELECT trosl, ctename.sqc FROM ctename) "*TROCRN*" (col1, col2, col3, sqc)
+ * )
+ *
+ * With a cycle clause
+ *
+ * CYCLE col1, col2 SET cmc TO 'Y' DEFAULT 'N' USING cpa
+ *
+ * (cmc = cycle mark column, cpa = cycle path) the CTE is rewritten to
+ *
+ * WITH RECURSIVE ctename (col1, col2, col3, cmc, cpa) AS (
+ * SELECT col1, col2, col3, -- original WITH column list
+ * 'N', -- cycle mark default
+ * ARRAY[ROW(col1, col2)] -- initial row of cycle columns
+ * FROM (query1) "*TLOCRN*" (col1, col2, col3)
+ * UNION [ALL]
+ * SELECT col1, col2, col3, -- same as above
+ * CASE WHEN ROW(col1, col2) = ANY (ARRAY[cpa]) THEN 'Y' ELSE 'N' END, -- compute cycle mark column
+ * cpa || ARRAY[ROW(col1, col2)] -- record rows seen
+ * FROM (SELECT trosl, ctename.cmc, ctename.cpa FROM ctename) "*TROCRN*" (col1, col2, col3, cmc, cpa)
+ * WHERE cmc <> 'Y'
+ * )
+ *
+ * The expression to compute the cycle mark column in the right-hand query is
+ * written as
+ *
+ * CASE WHEN ROW(col1, col2) IN (SELECT p.* FROM TABLE(cpa) p) THEN cmv ELSE cmd END
+ *
+ * in the SQL standard, but in PostgreSQL we can use the scalar-array operator
+ * expression shown above.
+ *
+ * Also, in some of the cases where operators are shown above we actually
+ * directly produce the underlying function call.
+ *
+ * If both a search clause and a cycle clause is specified, then the search
+ * clause column is added before the cycle clause columns.
+ */
+
+/*
+ * Make a RowExpr from the specified column names, which have to be among the
+ * output columns of the CTE.
+ */
+static RowExpr *
+make_path_rowexpr(const CommonTableExpr *cte, const List *col_list)
+{
+ RowExpr *rowexpr;
+ ListCell *lc;
+
+ rowexpr = makeNode(RowExpr);
+ rowexpr->row_typeid = RECORDOID;
+ rowexpr->row_format = COERCE_IMPLICIT_CAST;
+ rowexpr->location = -1;
+
+ foreach(lc, col_list)
+ {
+ char *colname = strVal(lfirst(lc));
+
+ for (int i = 0; i < list_length(cte->ctecolnames); i++)
+ {
+ char *colname2 = strVal(list_nth(cte->ctecolnames, i));
+
+ if (strcmp(colname, colname2) == 0)
+ {
+ Var *var;
+
+ var = makeVar(1, i + 1,
+ list_nth_oid(cte->ctecoltypes, i),
+ list_nth_int(cte->ctecoltypmods, i),
+ list_nth_oid(cte->ctecolcollations, i),
+ 0);
+ rowexpr->args = lappend(rowexpr->args, var);
+ rowexpr->colnames = lappend(rowexpr->colnames, makeString(colname));
+ break;
+ }
+ }
+ }
+
+ return rowexpr;
+}
+
+/*
+ * Wrap a RowExpr in an ArrayExpr, for the initial search depth first or cycle
+ * row.
+ */
+static Expr *
+make_path_initial_array(RowExpr *rowexpr)
+{
+ ArrayExpr *arr;
+
+ arr = makeNode(ArrayExpr);
+ arr->array_typeid = RECORDARRAYOID;
+ arr->element_typeid = RECORDOID;
+ arr->location = -1;
+ arr->elements = list_make1(rowexpr);
+
+ return (Expr *) arr;
+}
+
+/*
+ * Make an array catenation expression like
+ *
+ * cpa || ARRAY[ROW(cols)]
+ *
+ * where the varattno of cpa is provided as path_varattno.
+ */
+static Expr *
+make_path_cat_expr(RowExpr *rowexpr, AttrNumber path_varattno)
+{
+ ArrayExpr *arr;
+ FuncExpr *fexpr;
+
+ arr = makeNode(ArrayExpr);
+ arr->array_typeid = RECORDARRAYOID;
+ arr->element_typeid = RECORDOID;
+ arr->location = -1;
+ arr->elements = list_make1(rowexpr);
+
+ fexpr = makeFuncExpr(F_ARRAY_CAT, RECORDARRAYOID,
+ list_make2(makeVar(1, path_varattno, RECORDARRAYOID, -1, 0, 0),
+ arr),
+ InvalidOid, InvalidOid, COERCE_EXPLICIT_CALL);
+
+ return (Expr *) fexpr;
+}
+
+/*
+ * The real work happens here.
+ */
+CommonTableExpr *
+rewriteSearchAndCycle(CommonTableExpr *cte)
+{
+ Query *ctequery;
+ SetOperationStmt *sos;
+ int rti1,
+ rti2;
+ RangeTblEntry *rte1,
+ *rte2,
+ *newrte;
+ Query *newq1,
+ *newq2;
+ Query *newsubquery;
+ RangeTblRef *rtr;
+ Oid search_seq_type = InvalidOid;
+ AttrNumber sqc_attno = InvalidAttrNumber;
+ AttrNumber cmc_attno = InvalidAttrNumber;
+ AttrNumber cpa_attno = InvalidAttrNumber;
+ TargetEntry *tle;
+ RowExpr *cycle_col_rowexpr = NULL;
+ RowExpr *search_col_rowexpr = NULL;
+ List *ewcl;
+ int cte_rtindex = -1;
+
+ Assert(cte->search_clause || cte->cycle_clause);
+
+ cte = copyObject(cte);
+
+ ctequery = castNode(Query, cte->ctequery);
+
+ /*
+ * The top level of the CTE's query should be a UNION. Find the two
+ * subqueries.
+ */
+ Assert(ctequery->setOperations);
+ sos = castNode(SetOperationStmt, ctequery->setOperations);
+ Assert(sos->op == SETOP_UNION);
+
+ rti1 = castNode(RangeTblRef, sos->larg)->rtindex;
+ rti2 = castNode(RangeTblRef, sos->rarg)->rtindex;
+
+ rte1 = rt_fetch(rti1, ctequery->rtable);
+ rte2 = rt_fetch(rti2, ctequery->rtable);
+
+ Assert(rte1->rtekind == RTE_SUBQUERY);
+ Assert(rte2->rtekind == RTE_SUBQUERY);
+
+ /*
+ * We'll need this a few times later.
+ */
+ if (cte->search_clause)
+ {
+ if (cte->search_clause->search_breadth_first)
+ search_seq_type = RECORDOID;
+ else
+ search_seq_type = RECORDARRAYOID;
+ }
+
+ /*
+ * Attribute numbers of the added columns in the CTE's column list
+ */
+ if (cte->search_clause)
+ sqc_attno = list_length(cte->ctecolnames) + 1;
+ if (cte->cycle_clause)
+ {
+ cmc_attno = list_length(cte->ctecolnames) + 1;
+ cpa_attno = list_length(cte->ctecolnames) + 2;
+ if (cte->search_clause)
+ {
+ cmc_attno++;
+ cpa_attno++;
+ }
+ }
+
+ /*
+ * Make new left subquery
+ */
+ newq1 = makeNode(Query);
+ newq1->commandType = CMD_SELECT;
+ newq1->canSetTag = true;
+
+ newrte = makeNode(RangeTblEntry);
+ newrte->rtekind = RTE_SUBQUERY;
+ newrte->alias = makeAlias("*TLOCRN*", cte->ctecolnames);
+ newrte->eref = newrte->alias;
+ newsubquery = copyObject(rte1->subquery);
+ IncrementVarSublevelsUp((Node *) newsubquery, 1, 1);
+ newrte->subquery = newsubquery;
+ newrte->inFromCl = true;
+ newq1->rtable = list_make1(newrte);
+
+ rtr = makeNode(RangeTblRef);
+ rtr->rtindex = 1;
+ newq1->jointree = makeFromExpr(list_make1(rtr), NULL);
+
+ /*
+ * Make target list
+ */
+ for (int i = 0; i < list_length(cte->ctecolnames); i++)
+ {
+ Var *var;
+
+ var = makeVar(1, i + 1,
+ list_nth_oid(cte->ctecoltypes, i),
+ list_nth_int(cte->ctecoltypmods, i),
+ list_nth_oid(cte->ctecolcollations, i),
+ 0);
+ tle = makeTargetEntry((Expr *) var, i + 1, strVal(list_nth(cte->ctecolnames, i)), false);
+ tle->resorigtbl = castNode(TargetEntry, list_nth(rte1->subquery->targetList, i))->resorigtbl;
+ tle->resorigcol = castNode(TargetEntry, list_nth(rte1->subquery->targetList, i))->resorigcol;
+ newq1->targetList = lappend(newq1->targetList, tle);
+ }
+
+ if (cte->search_clause)
+ {
+ Expr *texpr;
+
+ search_col_rowexpr = make_path_rowexpr(cte, cte->search_clause->search_col_list);
+ if (cte->search_clause->search_breadth_first)
+ {
+ search_col_rowexpr->args = lcons(makeConst(INT8OID, -1, InvalidOid, sizeof(int64),
+ Int64GetDatum(0), false, FLOAT8PASSBYVAL),
+ search_col_rowexpr->args);
+ search_col_rowexpr->colnames = lcons(makeString("*DEPTH*"), search_col_rowexpr->colnames);
+ texpr = (Expr *) search_col_rowexpr;
+ }
+ else
+ texpr = make_path_initial_array(search_col_rowexpr);
+ tle = makeTargetEntry(texpr,
+ list_length(newq1->targetList) + 1,
+ cte->search_clause->search_seq_column,
+ false);
+ newq1->targetList = lappend(newq1->targetList, tle);
+ }
+ if (cte->cycle_clause)
+ {
+ tle = makeTargetEntry((Expr *) cte->cycle_clause->cycle_mark_default,
+ list_length(newq1->targetList) + 1,
+ cte->cycle_clause->cycle_mark_column,
+ false);
+ newq1->targetList = lappend(newq1->targetList, tle);
+ cycle_col_rowexpr = make_path_rowexpr(cte, cte->cycle_clause->cycle_col_list);
+ tle = makeTargetEntry(make_path_initial_array(cycle_col_rowexpr),
+ list_length(newq1->targetList) + 1,
+ cte->cycle_clause->cycle_path_column,
+ false);
+ newq1->targetList = lappend(newq1->targetList, tle);
+ }
+
+ rte1->subquery = newq1;
+
+ if (cte->search_clause)
+ {
+ rte1->eref->colnames = lappend(rte1->eref->colnames, makeString(cte->search_clause->search_seq_column));
+ }
+ if (cte->cycle_clause)
+ {
+ rte1->eref->colnames = lappend(rte1->eref->colnames, makeString(cte->cycle_clause->cycle_mark_column));
+ rte1->eref->colnames = lappend(rte1->eref->colnames, makeString(cte->cycle_clause->cycle_path_column));
+ }
+
+ /*
+ * Make new right subquery
+ */
+ newq2 = makeNode(Query);
+ newq2->commandType = CMD_SELECT;
+ newq2->canSetTag = true;
+
+ newrte = makeNode(RangeTblEntry);
+ newrte->rtekind = RTE_SUBQUERY;
+ ewcl = copyObject(cte->ctecolnames);
+ if (cte->search_clause)
+ {
+ ewcl = lappend(ewcl, makeString(cte->search_clause->search_seq_column));
+ }
+ if (cte->cycle_clause)
+ {
+ ewcl = lappend(ewcl, makeString(cte->cycle_clause->cycle_mark_column));
+ ewcl = lappend(ewcl, makeString(cte->cycle_clause->cycle_path_column));
+ }
+ newrte->alias = makeAlias("*TROCRN*", ewcl);
+ newrte->eref = newrte->alias;
+
+ /*
+ * Find the reference to our CTE in the range table
+ */
+ for (int rti = 1; rti <= list_length(rte2->subquery->rtable); rti++)
+ {
+ RangeTblEntry *e = rt_fetch(rti, rte2->subquery->rtable);
+
+ if (e->rtekind == RTE_CTE && strcmp(cte->ctename, e->ctename) == 0)
+ {
+ cte_rtindex = rti;
+ break;
+ }
+ }
+ Assert(cte_rtindex > 0);
+
+ newsubquery = copyObject(rte2->subquery);
+ IncrementVarSublevelsUp((Node *) newsubquery, 1, 1);
+
+ /*
+ * Add extra columns to target list of subquery of right subquery
+ */
+ if (cte->search_clause)
+ {
+ Var *var;
+
+ /* ctename.sqc */
+ var = makeVar(cte_rtindex, sqc_attno,
+ search_seq_type, -1, InvalidOid, 0);
+ tle = makeTargetEntry((Expr *) var,
+ list_length(newsubquery->targetList) + 1,
+ cte->search_clause->search_seq_column,
+ false);
+ newsubquery->targetList = lappend(newsubquery->targetList, tle);
+ }
+ if (cte->cycle_clause)
+ {
+ Var *var;
+
+ /* ctename.cmc */
+ var = makeVar(cte_rtindex, cmc_attno,
+ cte->cycle_clause->cycle_mark_type,
+ cte->cycle_clause->cycle_mark_typmod,
+ cte->cycle_clause->cycle_mark_collation, 0);
+ tle = makeTargetEntry((Expr *) var,
+ list_length(newsubquery->targetList) + 1,
+ cte->cycle_clause->cycle_mark_column,
+ false);
+ newsubquery->targetList = lappend(newsubquery->targetList, tle);
+
+ /* ctename.cpa */
+ var = makeVar(cte_rtindex, cpa_attno,
+ RECORDARRAYOID, -1, InvalidOid, 0);
+ tle = makeTargetEntry((Expr *) var,
+ list_length(newsubquery->targetList) + 1,
+ cte->cycle_clause->cycle_path_column,
+ false);
+ newsubquery->targetList = lappend(newsubquery->targetList, tle);
+ }
+
+ newrte->subquery = newsubquery;
+ newrte->inFromCl = true;
+ newq2->rtable = list_make1(newrte);
+
+ rtr = makeNode(RangeTblRef);
+ rtr->rtindex = 1;
+
+ if (cte->cycle_clause)
+ {
+ Expr *expr;
+
+ /*
+ * Add cmc <> cmv condition
+ */
+ expr = make_opclause(cte->cycle_clause->cycle_mark_neop, BOOLOID, false,
+ (Expr *) makeVar(1, cmc_attno,
+ cte->cycle_clause->cycle_mark_type,
+ cte->cycle_clause->cycle_mark_typmod,
+ cte->cycle_clause->cycle_mark_collation, 0),
+ (Expr *) cte->cycle_clause->cycle_mark_value,
+ InvalidOid,
+ cte->cycle_clause->cycle_mark_collation);
+
+ newq2->jointree = makeFromExpr(list_make1(rtr), (Node *) expr);
+ }
+ else
+ newq2->jointree = makeFromExpr(list_make1(rtr), NULL);
+
+ /*
+ * Make target list
+ */
+ for (int i = 0; i < list_length(cte->ctecolnames); i++)
+ {
+ Var *var;
+
+ var = makeVar(1, i + 1,
+ list_nth_oid(cte->ctecoltypes, i),
+ list_nth_int(cte->ctecoltypmods, i),
+ list_nth_oid(cte->ctecolcollations, i),
+ 0);
+ tle = makeTargetEntry((Expr *) var, i + 1, strVal(list_nth(cte->ctecolnames, i)), false);
+ tle->resorigtbl = castNode(TargetEntry, list_nth(rte2->subquery->targetList, i))->resorigtbl;
+ tle->resorigcol = castNode(TargetEntry, list_nth(rte2->subquery->targetList, i))->resorigcol;
+ newq2->targetList = lappend(newq2->targetList, tle);
+ }
+
+ if (cte->search_clause)
+ {
+ Expr *texpr;
+
+ if (cte->search_clause->search_breadth_first)
+ {
+ FieldSelect *fs;
+ FuncExpr *fexpr;
+
+ /*
+ * ROW(sqc.depth + 1, cols)
+ */
+
+ search_col_rowexpr = copyObject(search_col_rowexpr);
+
+ fs = makeNode(FieldSelect);
+ fs->arg = (Expr *) makeVar(1, sqc_attno, RECORDOID, -1, 0, 0);
+ fs->fieldnum = 1;
+ fs->resulttype = INT8OID;
+ fs->resulttypmod = -1;
+
+ fexpr = makeFuncExpr(F_INT8INC, INT8OID, list_make1(fs), InvalidOid, InvalidOid, COERCE_EXPLICIT_CALL);
+
+ lfirst(list_head(search_col_rowexpr->args)) = fexpr;
+
+ texpr = (Expr *) search_col_rowexpr;
+ }
+ else
+ {
+ /*
+ * sqc || ARRAY[ROW(cols)]
+ */
+ texpr = make_path_cat_expr(search_col_rowexpr, sqc_attno);
+ }
+ tle = makeTargetEntry(texpr,
+ list_length(newq2->targetList) + 1,
+ cte->search_clause->search_seq_column,
+ false);
+ newq2->targetList = lappend(newq2->targetList, tle);
+ }
+
+ if (cte->cycle_clause)
+ {
+ ScalarArrayOpExpr *saoe;
+ CaseExpr *caseexpr;
+ CaseWhen *casewhen;
+
+ /*
+ * CASE WHEN ROW(cols) = ANY (ARRAY[cpa]) THEN cmv ELSE cmd END
+ */
+
+ saoe = makeNode(ScalarArrayOpExpr);
+ saoe->location = -1;
+ saoe->opno = RECORD_EQ_OP;
+ saoe->useOr = true;
+ saoe->args = list_make2(cycle_col_rowexpr,
+ makeVar(1, cpa_attno, RECORDARRAYOID, -1, 0, 0));
+
+ caseexpr = makeNode(CaseExpr);
+ caseexpr->location = -1;
+ caseexpr->casetype = cte->cycle_clause->cycle_mark_type;
+ caseexpr->casecollid = cte->cycle_clause->cycle_mark_collation;
+ casewhen = makeNode(CaseWhen);
+ casewhen->location = -1;
+ casewhen->expr = (Expr *) saoe;
+ casewhen->result = (Expr *) cte->cycle_clause->cycle_mark_value;
+ caseexpr->args = list_make1(casewhen);
+ caseexpr->defresult = (Expr *) cte->cycle_clause->cycle_mark_default;
+
+ tle = makeTargetEntry((Expr *) caseexpr,
+ list_length(newq2->targetList) + 1,
+ cte->cycle_clause->cycle_mark_column,
+ false);
+ newq2->targetList = lappend(newq2->targetList, tle);
+
+ /*
+ * cpa || ARRAY[ROW(cols)]
+ */
+ tle = makeTargetEntry(make_path_cat_expr(cycle_col_rowexpr, cpa_attno),
+ list_length(newq2->targetList) + 1,
+ cte->cycle_clause->cycle_path_column,
+ false);
+ newq2->targetList = lappend(newq2->targetList, tle);
+ }
+
+ rte2->subquery = newq2;
+
+ if (cte->search_clause)
+ {
+ rte2->eref->colnames = lappend(rte2->eref->colnames, makeString(cte->search_clause->search_seq_column));
+ }
+ if (cte->cycle_clause)
+ {
+ rte2->eref->colnames = lappend(rte2->eref->colnames, makeString(cte->cycle_clause->cycle_mark_column));
+ rte2->eref->colnames = lappend(rte2->eref->colnames, makeString(cte->cycle_clause->cycle_path_column));
+ }
+
+ /*
+ * Add the additional columns to the SetOperationStmt
+ */
+ if (cte->search_clause)
+ {
+ sos->colTypes = lappend_oid(sos->colTypes, search_seq_type);
+ sos->colTypmods = lappend_int(sos->colTypmods, -1);
+ sos->colCollations = lappend_oid(sos->colCollations, InvalidOid);
+ if (!sos->all)
+ sos->groupClauses = lappend(sos->groupClauses,
+ makeSortGroupClauseForSetOp(search_seq_type));
+ }
+ if (cte->cycle_clause)
+ {
+ sos->colTypes = lappend_oid(sos->colTypes, cte->cycle_clause->cycle_mark_type);
+ sos->colTypmods = lappend_int(sos->colTypmods, cte->cycle_clause->cycle_mark_typmod);
+ sos->colCollations = lappend_oid(sos->colCollations, cte->cycle_clause->cycle_mark_collation);
+ if (!sos->all)
+ sos->groupClauses = lappend(sos->groupClauses,
+ makeSortGroupClauseForSetOp(cte->cycle_clause->cycle_mark_type));
+
+ sos->colTypes = lappend_oid(sos->colTypes, RECORDARRAYOID);
+ sos->colTypmods = lappend_int(sos->colTypmods, -1);
+ sos->colCollations = lappend_oid(sos->colCollations, InvalidOid);
+ if (!sos->all)
+ sos->groupClauses = lappend(sos->groupClauses,
+ makeSortGroupClauseForSetOp(RECORDARRAYOID));
+ }
+
+ /*
+ * Add the additional columns to the CTE query's target list
+ */
+ if (cte->search_clause)
+ {
+ ctequery->targetList = lappend(ctequery->targetList,
+ makeTargetEntry((Expr *) makeVar(1, sqc_attno,
+ search_seq_type, -1, InvalidOid, 0),
+ list_length(ctequery->targetList) + 1,
+ cte->search_clause->search_seq_column,
+ false));
+ }
+ if (cte->cycle_clause)
+ {
+ ctequery->targetList = lappend(ctequery->targetList,
+ makeTargetEntry((Expr *) makeVar(1, cmc_attno,
+ cte->cycle_clause->cycle_mark_type,
+ cte->cycle_clause->cycle_mark_typmod,
+ cte->cycle_clause->cycle_mark_collation, 0),
+ list_length(ctequery->targetList) + 1,
+ cte->cycle_clause->cycle_mark_column,
+ false));
+ ctequery->targetList = lappend(ctequery->targetList,
+ makeTargetEntry((Expr *) makeVar(1, cpa_attno,
+ RECORDARRAYOID, -1, InvalidOid, 0),
+ list_length(ctequery->targetList) + 1,
+ cte->cycle_clause->cycle_path_column,
+ false));
+ }
+
+ /*
+ * Add the additional columns to the CTE's output columns
+ */
+ cte->ctecolnames = ewcl;
+ if (cte->search_clause)
+ {
+ cte->ctecoltypes = lappend_oid(cte->ctecoltypes, search_seq_type);
+ cte->ctecoltypmods = lappend_int(cte->ctecoltypmods, -1);
+ cte->ctecolcollations = lappend_oid(cte->ctecolcollations, InvalidOid);
+ }
+ if (cte->cycle_clause)
+ {
+ cte->ctecoltypes = lappend_oid(cte->ctecoltypes, cte->cycle_clause->cycle_mark_type);
+ cte->ctecoltypmods = lappend_int(cte->ctecoltypmods, cte->cycle_clause->cycle_mark_typmod);
+ cte->ctecolcollations = lappend_oid(cte->ctecolcollations, cte->cycle_clause->cycle_mark_collation);
+
+ cte->ctecoltypes = lappend_oid(cte->ctecoltypes, RECORDARRAYOID);
+ cte->ctecoltypmods = lappend_int(cte->ctecoltypmods, -1);
+ cte->ctecolcollations = lappend_oid(cte->ctecolcollations, InvalidOid);
+ }
+
+ return cte;
+}
if (PRETTY_INDENT(context))
appendContextKeyword(context, "", 0, 0, 0);
appendStringInfoChar(buf, ')');
+
+ if (cte->search_clause)
+ {
+ bool first = true;
+ ListCell *lc;
+
+ appendStringInfo(buf, " SEARCH %s FIRST BY ",
+ cte->search_clause->search_breadth_first ? "BREADTH" : "DEPTH");
+
+ foreach(lc, cte->search_clause->search_col_list)
+ {
+ if (first)
+ first = false;
+ else
+ appendStringInfoString(buf, ", ");
+ appendStringInfoString(buf,
+ quote_identifier(strVal(lfirst(lc))));
+ }
+
+ appendStringInfo(buf, " SET %s", quote_identifier(cte->search_clause->search_seq_column));
+ }
+
+ if (cte->cycle_clause)
+ {
+ bool first = true;
+ ListCell *lc;
+
+ appendStringInfoString(buf, " CYCLE ");
+
+ foreach(lc, cte->cycle_clause->cycle_col_list)
+ {
+ if (first)
+ first = false;
+ else
+ appendStringInfoString(buf, ", ");
+ appendStringInfoString(buf,
+ quote_identifier(strVal(lfirst(lc))));
+ }
+
+ appendStringInfo(buf, " SET %s", quote_identifier(cte->cycle_clause->cycle_mark_column));
+ appendStringInfoString(buf, " TO ");
+ get_rule_expr(cte->cycle_clause->cycle_mark_value, context, false);
+ appendStringInfoString(buf, " DEFAULT ");
+ get_rule_expr(cte->cycle_clause->cycle_mark_default, context, false);
+ appendStringInfo(buf, " USING %s", quote_identifier(cte->cycle_clause->cycle_path_column));
+ }
+
sep = ", ";
}
T_WithClause,
T_InferClause,
T_OnConflictClause,
+ T_CTESearchClause,
+ T_CTECycleClause,
T_CommonTableExpr,
T_RoleSpec,
T_TriggerTransition,
/*
* CommonTableExpr -
* representation of WITH list element
- *
- * We don't currently support the SEARCH or CYCLE clause.
*/
+
typedef enum CTEMaterialize
{
CTEMaterializeDefault, /* no option specified */
CTEMaterializeNever /* NOT MATERIALIZED */
} CTEMaterialize;
+typedef struct CTESearchClause
+{
+ NodeTag type;
+ List *search_col_list;
+ bool search_breadth_first;
+ char *search_seq_column;
+ int location;
+} CTESearchClause;
+
+typedef struct CTECycleClause
+{
+ NodeTag type;
+ List *cycle_col_list;
+ char *cycle_mark_column;
+ Node *cycle_mark_value;
+ Node *cycle_mark_default;
+ char *cycle_path_column;
+ int location;
+ /* These fields are set during parse analysis: */
+ Oid cycle_mark_type; /* common type of _value and _default */
+ int cycle_mark_typmod;
+ Oid cycle_mark_collation;
+ Oid cycle_mark_neop; /* <> operator for type */
+} CTECycleClause;
+
typedef struct CommonTableExpr
{
NodeTag type;
CTEMaterialize ctematerialized; /* is this an optimization fence? */
/* SelectStmt/InsertStmt/etc before parse analysis, Query afterwards: */
Node *ctequery; /* the CTE's subquery */
+ CTESearchClause *search_clause;
+ CTECycleClause *cycle_clause;
int location; /* token location, or -1 if unknown */
/* These fields are set during parse analysis: */
bool cterecursive; /* is this CTE actually recursive? */
extern List *BuildOnConflictExcludedTargetlist(Relation targetrel,
Index exclRelIndex);
+extern SortGroupClause *makeSortGroupClauseForSetOp(Oid rescoltype);
+
#endif /* ANALYZE_H */
PG_KEYWORD("bit", BIT, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("boolean", BOOLEAN_P, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("both", BOTH, RESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("breadth", BREADTH, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("by", BY, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("cache", CACHE, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("call", CALL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("delimiter", DELIMITER, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("delimiters", DELIMITERS, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("depends", DEPENDS, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("depth", DEPTH, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("desc", DESC, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("detach", DETACH, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("dictionary", DICTIONARY, UNRESERVED_KEYWORD, BARE_LABEL)
EXPR_KIND_CALL_ARGUMENT, /* procedure argument in CALL */
EXPR_KIND_COPY_WHERE, /* WHERE condition in COPY FROM */
EXPR_KIND_GENERATED_COLUMN, /* generation expression for a column */
+ EXPR_KIND_CYCLE_MARK, /* cycle mark value */
} ParseExprKind;
Oid p_varcollid; /* OID of collation, or InvalidOid */
Index p_varnosyn; /* rangetable index of syntactic referent */
AttrNumber p_varattnosyn; /* attribute number of syntactic referent */
+ bool p_dontexpand; /* not included in star expansion */
};
/* Support for parser_errposition_callback function */
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * rewriteSearchCycle.h
+ * Support for rewriting SEARCH and CYCLE clauses.
+ *
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/rewrite/rewriteSearchCycle.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef REWRITESEARCHCYCLE_H
+#define REWRITESEARCHCYCLE_H
+
+#include "nodes/parsenodes.h"
+
+extern CommonTableExpr *rewriteSearchAndCycle(CommonTableExpr *cte);
+
+#endif /* REWRITESEARCHCYCLE_H */
16 | {3,7,11,16} | (16,"{3,7,11,16}")
(16 rows)
+-- SEARCH clause
+create temp table graph0( f int, t int, label text );
+insert into graph0 values
+ (1, 2, 'arc 1 -> 2'),
+ (1, 3, 'arc 1 -> 3'),
+ (2, 3, 'arc 2 -> 3'),
+ (1, 4, 'arc 1 -> 4'),
+ (4, 5, 'arc 4 -> 5');
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set seq
+select * from search_graph order by seq;
+ f | t | label | seq
+---+---+------------+-------------------
+ 1 | 2 | arc 1 -> 2 | {"(1,2)"}
+ 2 | 3 | arc 2 -> 3 | {"(1,2)","(2,3)"}
+ 1 | 3 | arc 1 -> 3 | {"(1,3)"}
+ 1 | 4 | arc 1 -> 4 | {"(1,4)"}
+ 4 | 5 | arc 4 -> 5 | {"(1,4)","(4,5)"}
+ 2 | 3 | arc 2 -> 3 | {"(2,3)"}
+ 4 | 5 | arc 4 -> 5 | {"(4,5)"}
+(7 rows)
+
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union distinct
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set seq
+select * from search_graph order by seq;
+ f | t | label | seq
+---+---+------------+-------------------
+ 1 | 2 | arc 1 -> 2 | {"(1,2)"}
+ 2 | 3 | arc 2 -> 3 | {"(1,2)","(2,3)"}
+ 1 | 3 | arc 1 -> 3 | {"(1,3)"}
+ 1 | 4 | arc 1 -> 4 | {"(1,4)"}
+ 4 | 5 | arc 4 -> 5 | {"(1,4)","(4,5)"}
+ 2 | 3 | arc 2 -> 3 | {"(2,3)"}
+ 4 | 5 | arc 4 -> 5 | {"(4,5)"}
+(7 rows)
+
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search breadth first by f, t set seq
+select * from search_graph order by seq;
+ f | t | label | seq
+---+---+------------+---------
+ 1 | 2 | arc 1 -> 2 | (0,1,2)
+ 1 | 3 | arc 1 -> 3 | (0,1,3)
+ 1 | 4 | arc 1 -> 4 | (0,1,4)
+ 2 | 3 | arc 2 -> 3 | (0,2,3)
+ 4 | 5 | arc 4 -> 5 | (0,4,5)
+ 2 | 3 | arc 2 -> 3 | (1,2,3)
+ 4 | 5 | arc 4 -> 5 | (1,4,5)
+(7 rows)
+
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union distinct
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search breadth first by f, t set seq
+select * from search_graph order by seq;
+ f | t | label | seq
+---+---+------------+---------
+ 1 | 2 | arc 1 -> 2 | (0,1,2)
+ 1 | 3 | arc 1 -> 3 | (0,1,3)
+ 1 | 4 | arc 1 -> 4 | (0,1,4)
+ 2 | 3 | arc 2 -> 3 | (0,2,3)
+ 4 | 5 | arc 4 -> 5 | (0,4,5)
+ 2 | 3 | arc 2 -> 3 | (1,2,3)
+ 4 | 5 | arc 4 -> 5 | (1,4,5)
+(7 rows)
+
+-- various syntax errors
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by foo, tar set seq
+select * from search_graph;
+ERROR: search column "foo" not in WITH query column list
+LINE 7: ) search depth first by foo, tar set seq
+ ^
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set label
+select * from search_graph;
+ERROR: search sequence column name "label" already used in WITH query column list
+LINE 7: ) search depth first by f, t set label
+ ^
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t, f set seq
+select * from search_graph;
+ERROR: search column "f" specified more than once
+LINE 7: ) search depth first by f, t, f set seq
+ ^
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set seq
+select * from search_graph order by seq;
+ERROR: with a SEARCH or CYCLE clause, the left side of the UNION must be a SELECT
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ (select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t)
+) search depth first by f, t set seq
+select * from search_graph order by seq;
+ERROR: with a SEARCH or CYCLE clause, the right side of the UNION must be a SELECT
+-- test ruleutils and view expansion
+create temp view v_search as
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set seq
+select f, t, label from search_graph;
+select pg_get_viewdef('v_search');
+ pg_get_viewdef
+------------------------------------------------
+ WITH RECURSIVE search_graph(f, t, label) AS (+
+ SELECT g.f, +
+ g.t, +
+ g.label +
+ FROM graph0 g +
+ UNION ALL +
+ SELECT g.f, +
+ g.t, +
+ g.label +
+ FROM graph0 g, +
+ search_graph sg +
+ WHERE (g.f = sg.t) +
+ ) SEARCH DEPTH FIRST BY f, t SET seq +
+ SELECT search_graph.f, +
+ search_graph.t, +
+ search_graph.label +
+ FROM search_graph;
+(1 row)
+
+select * from v_search;
+ f | t | label
+---+---+------------
+ 1 | 2 | arc 1 -> 2
+ 1 | 3 | arc 1 -> 3
+ 2 | 3 | arc 2 -> 3
+ 1 | 4 | arc 1 -> 4
+ 4 | 5 | arc 4 -> 5
+ 2 | 3 | arc 2 -> 3
+ 4 | 5 | arc 4 -> 5
+(7 rows)
+
--
-- test cycle detection
--
5 | 1 | arc 5 -> 1 | t | {"(5,1)","(1,4)","(4,5)","(5,1)"}
(25 rows)
+-- CYCLE clause
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to true default false using path
+select * from search_graph;
+ f | t | label | is_cycle | path
+---+---+------------+----------+-------------------------------------------
+ 1 | 2 | arc 1 -> 2 | f | {"(1,2)"}
+ 1 | 3 | arc 1 -> 3 | f | {"(1,3)"}
+ 2 | 3 | arc 2 -> 3 | f | {"(2,3)"}
+ 1 | 4 | arc 1 -> 4 | f | {"(1,4)"}
+ 4 | 5 | arc 4 -> 5 | f | {"(4,5)"}
+ 5 | 1 | arc 5 -> 1 | f | {"(5,1)"}
+ 1 | 2 | arc 1 -> 2 | f | {"(5,1)","(1,2)"}
+ 1 | 3 | arc 1 -> 3 | f | {"(5,1)","(1,3)"}
+ 1 | 4 | arc 1 -> 4 | f | {"(5,1)","(1,4)"}
+ 2 | 3 | arc 2 -> 3 | f | {"(1,2)","(2,3)"}
+ 4 | 5 | arc 4 -> 5 | f | {"(1,4)","(4,5)"}
+ 5 | 1 | arc 5 -> 1 | f | {"(4,5)","(5,1)"}
+ 1 | 2 | arc 1 -> 2 | f | {"(4,5)","(5,1)","(1,2)"}
+ 1 | 3 | arc 1 -> 3 | f | {"(4,5)","(5,1)","(1,3)"}
+ 1 | 4 | arc 1 -> 4 | f | {"(4,5)","(5,1)","(1,4)"}
+ 2 | 3 | arc 2 -> 3 | f | {"(5,1)","(1,2)","(2,3)"}
+ 4 | 5 | arc 4 -> 5 | f | {"(5,1)","(1,4)","(4,5)"}
+ 5 | 1 | arc 5 -> 1 | f | {"(1,4)","(4,5)","(5,1)"}
+ 1 | 2 | arc 1 -> 2 | f | {"(1,4)","(4,5)","(5,1)","(1,2)"}
+ 1 | 3 | arc 1 -> 3 | f | {"(1,4)","(4,5)","(5,1)","(1,3)"}
+ 1 | 4 | arc 1 -> 4 | t | {"(1,4)","(4,5)","(5,1)","(1,4)"}
+ 2 | 3 | arc 2 -> 3 | f | {"(4,5)","(5,1)","(1,2)","(2,3)"}
+ 4 | 5 | arc 4 -> 5 | t | {"(4,5)","(5,1)","(1,4)","(4,5)"}
+ 5 | 1 | arc 5 -> 1 | t | {"(5,1)","(1,4)","(4,5)","(5,1)"}
+ 2 | 3 | arc 2 -> 3 | f | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"}
+(25 rows)
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union distinct
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to 'Y' default 'N' using path
+select * from search_graph;
+ f | t | label | is_cycle | path
+---+---+------------+----------+-------------------------------------------
+ 1 | 2 | arc 1 -> 2 | N | {"(1,2)"}
+ 1 | 3 | arc 1 -> 3 | N | {"(1,3)"}
+ 2 | 3 | arc 2 -> 3 | N | {"(2,3)"}
+ 1 | 4 | arc 1 -> 4 | N | {"(1,4)"}
+ 4 | 5 | arc 4 -> 5 | N | {"(4,5)"}
+ 5 | 1 | arc 5 -> 1 | N | {"(5,1)"}
+ 1 | 2 | arc 1 -> 2 | N | {"(5,1)","(1,2)"}
+ 1 | 3 | arc 1 -> 3 | N | {"(5,1)","(1,3)"}
+ 1 | 4 | arc 1 -> 4 | N | {"(5,1)","(1,4)"}
+ 2 | 3 | arc 2 -> 3 | N | {"(1,2)","(2,3)"}
+ 4 | 5 | arc 4 -> 5 | N | {"(1,4)","(4,5)"}
+ 5 | 1 | arc 5 -> 1 | N | {"(4,5)","(5,1)"}
+ 1 | 2 | arc 1 -> 2 | N | {"(4,5)","(5,1)","(1,2)"}
+ 1 | 3 | arc 1 -> 3 | N | {"(4,5)","(5,1)","(1,3)"}
+ 1 | 4 | arc 1 -> 4 | N | {"(4,5)","(5,1)","(1,4)"}
+ 2 | 3 | arc 2 -> 3 | N | {"(5,1)","(1,2)","(2,3)"}
+ 4 | 5 | arc 4 -> 5 | N | {"(5,1)","(1,4)","(4,5)"}
+ 5 | 1 | arc 5 -> 1 | N | {"(1,4)","(4,5)","(5,1)"}
+ 1 | 2 | arc 1 -> 2 | N | {"(1,4)","(4,5)","(5,1)","(1,2)"}
+ 1 | 3 | arc 1 -> 3 | N | {"(1,4)","(4,5)","(5,1)","(1,3)"}
+ 1 | 4 | arc 1 -> 4 | Y | {"(1,4)","(4,5)","(5,1)","(1,4)"}
+ 2 | 3 | arc 2 -> 3 | N | {"(4,5)","(5,1)","(1,2)","(2,3)"}
+ 4 | 5 | arc 4 -> 5 | Y | {"(4,5)","(5,1)","(1,4)","(4,5)"}
+ 5 | 1 | arc 5 -> 1 | Y | {"(5,1)","(1,4)","(4,5)","(5,1)"}
+ 2 | 3 | arc 2 -> 3 | N | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"}
+(25 rows)
+
+-- multiple CTEs
+with recursive
+graph(f, t, label) as (
+ values (1, 2, 'arc 1 -> 2'),
+ (1, 3, 'arc 1 -> 3'),
+ (2, 3, 'arc 2 -> 3'),
+ (1, 4, 'arc 1 -> 4'),
+ (4, 5, 'arc 4 -> 5'),
+ (5, 1, 'arc 5 -> 1')
+),
+search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to true default false using path
+select f, t, label from search_graph;
+ f | t | label
+---+---+------------
+ 1 | 2 | arc 1 -> 2
+ 1 | 3 | arc 1 -> 3
+ 2 | 3 | arc 2 -> 3
+ 1 | 4 | arc 1 -> 4
+ 4 | 5 | arc 4 -> 5
+ 5 | 1 | arc 5 -> 1
+ 2 | 3 | arc 2 -> 3
+ 4 | 5 | arc 4 -> 5
+ 5 | 1 | arc 5 -> 1
+ 1 | 4 | arc 1 -> 4
+ 1 | 3 | arc 1 -> 3
+ 1 | 2 | arc 1 -> 2
+ 5 | 1 | arc 5 -> 1
+ 1 | 4 | arc 1 -> 4
+ 1 | 3 | arc 1 -> 3
+ 1 | 2 | arc 1 -> 2
+ 4 | 5 | arc 4 -> 5
+ 2 | 3 | arc 2 -> 3
+ 1 | 4 | arc 1 -> 4
+ 1 | 3 | arc 1 -> 3
+ 1 | 2 | arc 1 -> 2
+ 4 | 5 | arc 4 -> 5
+ 2 | 3 | arc 2 -> 3
+ 5 | 1 | arc 5 -> 1
+ 2 | 3 | arc 2 -> 3
+(25 rows)
+
+-- star expansion
+with recursive a as (
+ select 1 as b
+ union all
+ select * from a
+) cycle b set c to true default false using p
+select * from a;
+ b | c | p
+---+---+-----------
+ 1 | f | {(1)}
+ 1 | t | {(1),(1)}
+(2 rows)
+
+-- search+cycle
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set seq
+ cycle f, t set is_cycle to true default false using path
+select * from search_graph;
+ f | t | label | seq | is_cycle | path
+---+---+------------+-------------------------------------------+----------+-------------------------------------------
+ 1 | 2 | arc 1 -> 2 | {"(1,2)"} | f | {"(1,2)"}
+ 1 | 3 | arc 1 -> 3 | {"(1,3)"} | f | {"(1,3)"}
+ 2 | 3 | arc 2 -> 3 | {"(2,3)"} | f | {"(2,3)"}
+ 1 | 4 | arc 1 -> 4 | {"(1,4)"} | f | {"(1,4)"}
+ 4 | 5 | arc 4 -> 5 | {"(4,5)"} | f | {"(4,5)"}
+ 5 | 1 | arc 5 -> 1 | {"(5,1)"} | f | {"(5,1)"}
+ 1 | 2 | arc 1 -> 2 | {"(5,1)","(1,2)"} | f | {"(5,1)","(1,2)"}
+ 1 | 3 | arc 1 -> 3 | {"(5,1)","(1,3)"} | f | {"(5,1)","(1,3)"}
+ 1 | 4 | arc 1 -> 4 | {"(5,1)","(1,4)"} | f | {"(5,1)","(1,4)"}
+ 2 | 3 | arc 2 -> 3 | {"(1,2)","(2,3)"} | f | {"(1,2)","(2,3)"}
+ 4 | 5 | arc 4 -> 5 | {"(1,4)","(4,5)"} | f | {"(1,4)","(4,5)"}
+ 5 | 1 | arc 5 -> 1 | {"(4,5)","(5,1)"} | f | {"(4,5)","(5,1)"}
+ 1 | 2 | arc 1 -> 2 | {"(4,5)","(5,1)","(1,2)"} | f | {"(4,5)","(5,1)","(1,2)"}
+ 1 | 3 | arc 1 -> 3 | {"(4,5)","(5,1)","(1,3)"} | f | {"(4,5)","(5,1)","(1,3)"}
+ 1 | 4 | arc 1 -> 4 | {"(4,5)","(5,1)","(1,4)"} | f | {"(4,5)","(5,1)","(1,4)"}
+ 2 | 3 | arc 2 -> 3 | {"(5,1)","(1,2)","(2,3)"} | f | {"(5,1)","(1,2)","(2,3)"}
+ 4 | 5 | arc 4 -> 5 | {"(5,1)","(1,4)","(4,5)"} | f | {"(5,1)","(1,4)","(4,5)"}
+ 5 | 1 | arc 5 -> 1 | {"(1,4)","(4,5)","(5,1)"} | f | {"(1,4)","(4,5)","(5,1)"}
+ 1 | 2 | arc 1 -> 2 | {"(1,4)","(4,5)","(5,1)","(1,2)"} | f | {"(1,4)","(4,5)","(5,1)","(1,2)"}
+ 1 | 3 | arc 1 -> 3 | {"(1,4)","(4,5)","(5,1)","(1,3)"} | f | {"(1,4)","(4,5)","(5,1)","(1,3)"}
+ 1 | 4 | arc 1 -> 4 | {"(1,4)","(4,5)","(5,1)","(1,4)"} | t | {"(1,4)","(4,5)","(5,1)","(1,4)"}
+ 2 | 3 | arc 2 -> 3 | {"(4,5)","(5,1)","(1,2)","(2,3)"} | f | {"(4,5)","(5,1)","(1,2)","(2,3)"}
+ 4 | 5 | arc 4 -> 5 | {"(4,5)","(5,1)","(1,4)","(4,5)"} | t | {"(4,5)","(5,1)","(1,4)","(4,5)"}
+ 5 | 1 | arc 5 -> 1 | {"(5,1)","(1,4)","(4,5)","(5,1)"} | t | {"(5,1)","(1,4)","(4,5)","(5,1)"}
+ 2 | 3 | arc 2 -> 3 | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"} | f | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"}
+(25 rows)
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) search breadth first by f, t set seq
+ cycle f, t set is_cycle to true default false using path
+select * from search_graph;
+ f | t | label | seq | is_cycle | path
+---+---+------------+---------+----------+-------------------------------------------
+ 1 | 2 | arc 1 -> 2 | (0,1,2) | f | {"(1,2)"}
+ 1 | 3 | arc 1 -> 3 | (0,1,3) | f | {"(1,3)"}
+ 2 | 3 | arc 2 -> 3 | (0,2,3) | f | {"(2,3)"}
+ 1 | 4 | arc 1 -> 4 | (0,1,4) | f | {"(1,4)"}
+ 4 | 5 | arc 4 -> 5 | (0,4,5) | f | {"(4,5)"}
+ 5 | 1 | arc 5 -> 1 | (0,5,1) | f | {"(5,1)"}
+ 1 | 2 | arc 1 -> 2 | (1,1,2) | f | {"(5,1)","(1,2)"}
+ 1 | 3 | arc 1 -> 3 | (1,1,3) | f | {"(5,1)","(1,3)"}
+ 1 | 4 | arc 1 -> 4 | (1,1,4) | f | {"(5,1)","(1,4)"}
+ 2 | 3 | arc 2 -> 3 | (1,2,3) | f | {"(1,2)","(2,3)"}
+ 4 | 5 | arc 4 -> 5 | (1,4,5) | f | {"(1,4)","(4,5)"}
+ 5 | 1 | arc 5 -> 1 | (1,5,1) | f | {"(4,5)","(5,1)"}
+ 1 | 2 | arc 1 -> 2 | (2,1,2) | f | {"(4,5)","(5,1)","(1,2)"}
+ 1 | 3 | arc 1 -> 3 | (2,1,3) | f | {"(4,5)","(5,1)","(1,3)"}
+ 1 | 4 | arc 1 -> 4 | (2,1,4) | f | {"(4,5)","(5,1)","(1,4)"}
+ 2 | 3 | arc 2 -> 3 | (2,2,3) | f | {"(5,1)","(1,2)","(2,3)"}
+ 4 | 5 | arc 4 -> 5 | (2,4,5) | f | {"(5,1)","(1,4)","(4,5)"}
+ 5 | 1 | arc 5 -> 1 | (2,5,1) | f | {"(1,4)","(4,5)","(5,1)"}
+ 1 | 2 | arc 1 -> 2 | (3,1,2) | f | {"(1,4)","(4,5)","(5,1)","(1,2)"}
+ 1 | 3 | arc 1 -> 3 | (3,1,3) | f | {"(1,4)","(4,5)","(5,1)","(1,3)"}
+ 1 | 4 | arc 1 -> 4 | (3,1,4) | t | {"(1,4)","(4,5)","(5,1)","(1,4)"}
+ 2 | 3 | arc 2 -> 3 | (3,2,3) | f | {"(4,5)","(5,1)","(1,2)","(2,3)"}
+ 4 | 5 | arc 4 -> 5 | (3,4,5) | t | {"(4,5)","(5,1)","(1,4)","(4,5)"}
+ 5 | 1 | arc 5 -> 1 | (3,5,1) | t | {"(5,1)","(1,4)","(4,5)","(5,1)"}
+ 2 | 3 | arc 2 -> 3 | (4,2,3) | f | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"}
+(25 rows)
+
+-- various syntax errors
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle foo, tar set is_cycle to true default false using path
+select * from search_graph;
+ERROR: cycle column "foo" not in WITH query column list
+LINE 7: ) cycle foo, tar set is_cycle to true default false using pa...
+ ^
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to true default 55 using path
+select * from search_graph;
+ERROR: CYCLE types boolean and integer cannot be matched
+LINE 7: ) cycle f, t set is_cycle to true default 55 using path
+ ^
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to point '(1,1)' default point '(0,0)' using path
+select * from search_graph;
+ERROR: could not identify an equality operator for type point
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set label to true default false using path
+select * from search_graph;
+ERROR: cycle mark column name "label" already used in WITH query column list
+LINE 7: ) cycle f, t set label to true default false using path
+ ^
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to true default false using label
+select * from search_graph;
+ERROR: cycle path column name "label" already used in WITH query column list
+LINE 7: ) cycle f, t set is_cycle to true default false using label
+ ^
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set foo to true default false using foo
+select * from search_graph;
+ERROR: cycle mark column name and cycle path column name are the same
+LINE 7: ) cycle f, t set foo to true default false using foo
+ ^
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t, f set is_cycle to true default false using path
+select * from search_graph;
+ERROR: cycle column "f" specified more than once
+LINE 7: ) cycle f, t, f set is_cycle to true default false using pat...
+ ^
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set foo
+ cycle f, t set foo to true default false using path
+select * from search_graph;
+ERROR: search sequence column name and cycle mark column name are the same
+LINE 7: ) search depth first by f, t set foo
+ ^
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set foo
+ cycle f, t set is_cycle to true default false using foo
+select * from search_graph;
+ERROR: search_sequence column name and cycle path column name are the same
+LINE 7: ) search depth first by f, t set foo
+ ^
+-- test ruleutils and view expansion
+create temp view v_cycle as
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to true default false using path
+select f, t, label from search_graph;
+select pg_get_viewdef('v_cycle');
+ pg_get_viewdef
+--------------------------------------------------------------------
+ WITH RECURSIVE search_graph(f, t, label) AS ( +
+ SELECT g.f, +
+ g.t, +
+ g.label +
+ FROM graph g +
+ UNION ALL +
+ SELECT g.f, +
+ g.t, +
+ g.label +
+ FROM graph g, +
+ search_graph sg +
+ WHERE (g.f = sg.t) +
+ ) CYCLE f, t SET is_cycle TO true DEFAULT false USING path+
+ SELECT search_graph.f, +
+ search_graph.t, +
+ search_graph.label +
+ FROM search_graph;
+(1 row)
+
+select * from v_cycle;
+ f | t | label
+---+---+------------
+ 1 | 2 | arc 1 -> 2
+ 1 | 3 | arc 1 -> 3
+ 2 | 3 | arc 2 -> 3
+ 1 | 4 | arc 1 -> 4
+ 4 | 5 | arc 4 -> 5
+ 5 | 1 | arc 5 -> 1
+ 1 | 2 | arc 1 -> 2
+ 1 | 3 | arc 1 -> 3
+ 1 | 4 | arc 1 -> 4
+ 2 | 3 | arc 2 -> 3
+ 4 | 5 | arc 4 -> 5
+ 5 | 1 | arc 5 -> 1
+ 1 | 2 | arc 1 -> 2
+ 1 | 3 | arc 1 -> 3
+ 1 | 4 | arc 1 -> 4
+ 2 | 3 | arc 2 -> 3
+ 4 | 5 | arc 4 -> 5
+ 5 | 1 | arc 5 -> 1
+ 1 | 2 | arc 1 -> 2
+ 1 | 3 | arc 1 -> 3
+ 1 | 4 | arc 1 -> 4
+ 2 | 3 | arc 2 -> 3
+ 4 | 5 | arc 4 -> 5
+ 5 | 1 | arc 5 -> 1
+ 2 | 3 | arc 2 -> 3
+(25 rows)
+
--
-- test multiple WITH queries
--
SELECT t1.id, t2.path, t2 FROM t AS t1 JOIN t AS t2 ON
(t1.id=t2.id);
+-- SEARCH clause
+
+create temp table graph0( f int, t int, label text );
+
+insert into graph0 values
+ (1, 2, 'arc 1 -> 2'),
+ (1, 3, 'arc 1 -> 3'),
+ (2, 3, 'arc 2 -> 3'),
+ (1, 4, 'arc 1 -> 4'),
+ (4, 5, 'arc 4 -> 5');
+
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set seq
+select * from search_graph order by seq;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union distinct
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set seq
+select * from search_graph order by seq;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search breadth first by f, t set seq
+select * from search_graph order by seq;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union distinct
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search breadth first by f, t set seq
+select * from search_graph order by seq;
+
+-- various syntax errors
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by foo, tar set seq
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set label
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t, f set seq
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set seq
+select * from search_graph order by seq;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ (select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t)
+) search depth first by f, t set seq
+select * from search_graph order by seq;
+
+-- test ruleutils and view expansion
+create temp view v_search as
+with recursive search_graph(f, t, label) as (
+ select * from graph0 g
+ union all
+ select g.*
+ from graph0 g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set seq
+select f, t, label from search_graph;
+
+select pg_get_viewdef('v_search');
+
+select * from v_search;
+
--
-- test cycle detection
--
)
select * from search_graph order by path;
+-- CYCLE clause
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to true default false using path
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union distinct
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to 'Y' default 'N' using path
+select * from search_graph;
+
+-- multiple CTEs
+with recursive
+graph(f, t, label) as (
+ values (1, 2, 'arc 1 -> 2'),
+ (1, 3, 'arc 1 -> 3'),
+ (2, 3, 'arc 2 -> 3'),
+ (1, 4, 'arc 1 -> 4'),
+ (4, 5, 'arc 4 -> 5'),
+ (5, 1, 'arc 5 -> 1')
+),
+search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to true default false using path
+select f, t, label from search_graph;
+
+-- star expansion
+with recursive a as (
+ select 1 as b
+ union all
+ select * from a
+) cycle b set c to true default false using p
+select * from a;
+
+-- search+cycle
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set seq
+ cycle f, t set is_cycle to true default false using path
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) search breadth first by f, t set seq
+ cycle f, t set is_cycle to true default false using path
+select * from search_graph;
+
+-- various syntax errors
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle foo, tar set is_cycle to true default false using path
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to true default 55 using path
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to point '(1,1)' default point '(0,0)' using path
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set label to true default false using path
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to true default false using label
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set foo to true default false using foo
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t, f set is_cycle to true default false using path
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set foo
+ cycle f, t set foo to true default false using path
+select * from search_graph;
+
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) search depth first by f, t set foo
+ cycle f, t set is_cycle to true default false using foo
+select * from search_graph;
+
+-- test ruleutils and view expansion
+create temp view v_cycle as
+with recursive search_graph(f, t, label) as (
+ select * from graph g
+ union all
+ select g.*
+ from graph g, search_graph sg
+ where g.f = sg.t
+) cycle f, t set is_cycle to true default false using path
+select f, t, label from search_graph;
+
+select pg_get_viewdef('v_cycle');
+
+select * from v_cycle;
+
--
-- test multiple WITH queries
--
projects / postgresql.git / commitdiff