Fix ALTER COLUMN TYPE to preserve the tablespace and reloptions of indexes

it affects.  The original coding neglected tablespace entirely (causing
the indexes to move to the database's default tablespace) and for an index
belonging to a UNIQUE or PRIMARY KEY constraint, it would actually try to
assign the parent table's reloptions to the index :-(.  Per bug #3672 and
subsequent investigation.

8.0 and 8.1 did not have reloptions, but the tablespace bug is present.

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 613d7982456a69cfb5aee3409a086a902584eb09..ba24ba96f6c7351f713507202b0e168050058f0e 100644 (file)
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -54,6 +54,7 @@
 #include "catalog/pg_opclass.h"
 #include "catalog/pg_operator.h"
 #include "catalog/pg_trigger.h"
+#include "commands/tablespace.h"
 #include "executor/spi.h"
 #include "funcapi.h"
 #include "lib/stringinfo.h"
@@ -157,12 +158,13 @@ static char *pg_get_viewdef_worker(Oid viewoid, int prettyFlags);
 static void decompile_column_index_array(Datum column_index_array, Oid relId,
                                                         StringInfo buf);
 static char *pg_get_ruledef_worker(Oid ruleoid, int prettyFlags);
-static char *pg_get_indexdef_worker(Oid indexrelid, int colno,
+static char *pg_get_indexdef_worker(Oid indexrelid, int colno, bool showTblSpc,
                                           int prettyFlags);
 static char *pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
                                                        int prettyFlags);
 static char *pg_get_expr_worker(text *expr, Oid relid, char *relname,
                                   int prettyFlags);
+static Oid     get_constraint_index(Oid constraintId);
 static void make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
                         int prettyFlags);
 static void make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
@@ -596,6 +598,10 @@ pg_get_triggerdef(PG_FUNCTION_ARGS)
  * In the extended version, there is a colno argument as well as pretty bool.
  *     if colno == 0, we want a complete index definition.
  *     if colno > 0, we only want the Nth index key's variable or expression.
+ *
+ * Note that the SQL-function versions of this omit any info about the
+ * index tablespace; this is intentional because pg_dump wants it that way.
+ * However pg_get_indexdef_string() includes index tablespace if not default.
  * ----------
  */
 Datum
@@ -603,7 +609,8 @@ pg_get_indexdef(PG_FUNCTION_ARGS)
 {
        Oid                     indexrelid = PG_GETARG_OID(0);
 
-       PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, 0, 0)));
+       PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, 0,
+                                                                                                                  false, 0)));
 }
 
 Datum
@@ -615,18 +622,20 @@ pg_get_indexdef_ext(PG_FUNCTION_ARGS)
        int                     prettyFlags;
 
        prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : 0;
-       PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, colno, prettyFlags)));
+       PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, colno,
+                                                                                                                false, prettyFlags)));
 }
 
 /* Internal version that returns a palloc'd C string */
 char *
 pg_get_indexdef_string(Oid indexrelid)
 {
-       return pg_get_indexdef_worker(indexrelid, 0, 0);
+       return pg_get_indexdef_worker(indexrelid, 0, true, 0);
 }
 
 static char *
-pg_get_indexdef_worker(Oid indexrelid, int colno, int prettyFlags)
+pg_get_indexdef_worker(Oid indexrelid, int colno, bool showTblSpc,
+                                          int prettyFlags)
 {
        HeapTuple       ht_idx;
        HeapTuple       ht_idxrel;
@@ -784,6 +793,19 @@ pg_get_indexdef_worker(Oid indexrelid, int colno, int prettyFlags)
        {
                appendStringInfoChar(&buf, ')');
 
+               /*
+                * If it's in a nondefault tablespace, say so, but only if requested
+                */
+               if (showTblSpc)
+               {
+                       Oid                     tblspc;
+
+                       tblspc = get_rel_tablespace(indexrelid);
+                       if (OidIsValid(tblspc))
+                               appendStringInfo(&buf, " TABLESPACE %s",
+                                                                quote_identifier(get_tablespace_name(tblspc)));
+               }
+
                /*
                 * If it's a partial index, decompile and append the predicate
                 */
@@ -1012,6 +1034,7 @@ pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
                        {
                                Datum           val;
                                bool            isnull;
+                               Oid                     indexId;
 
                                /* Start off the constraint definition */
                                if (conForm->contype == CONSTRAINT_PRIMARY)
@@ -1029,6 +1052,20 @@ pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
                                decompile_column_index_array(val, conForm->conrelid, &buf);
 
                                appendStringInfo(&buf, ")");
+
+                               indexId = get_constraint_index(constraintId);
+
+                               /* XXX why do we only print this bit if fullCommand? */
+                               if (fullCommand && OidIsValid(indexId))
+                               {
+                                       Oid                     tblspc;
+
+                                       tblspc = get_rel_tablespace(indexId);
+                                       if (OidIsValid(tblspc))
+                                               appendStringInfo(&buf, " USING INDEX TABLESPACE %s",
+                                                                                quote_identifier(get_tablespace_name(tblspc)));
+                               }
+
                                break;
                        }
                case CONSTRAINT_CHECK:
@@ -1339,7 +1376,69 @@ pg_get_serial_sequence(PG_FUNCTION_ARGS)
 }
 
 
-/* ----------
+/*
+ * get_constraint_index
+ *             Given the OID of a unique or primary-key constraint, return the
+ *             OID of the underlying unique index.
+ *
+ * Return InvalidOid if the index couldn't be found; this suggests the
+ * given OID is bogus, but we leave it to caller to decide what to do.
+ */
+static Oid
+get_constraint_index(Oid constraintId)
+{
+       Oid                     indexId = InvalidOid;
+       Relation        depRel;
+       ScanKeyData key[3];
+       SysScanDesc scan;
+       HeapTuple       tup;
+
+       /* Search the dependency table for the dependent index */
+       depRel = heap_open(DependRelationId, AccessShareLock);
+
+       ScanKeyInit(&key[0],
+                               Anum_pg_depend_refclassid,
+                               BTEqualStrategyNumber, F_OIDEQ,
+                               ObjectIdGetDatum(ConstraintRelationId));
+       ScanKeyInit(&key[1],
+                               Anum_pg_depend_refobjid,
+                               BTEqualStrategyNumber, F_OIDEQ,
+                               ObjectIdGetDatum(constraintId));
+       ScanKeyInit(&key[2],
+                               Anum_pg_depend_refobjsubid,
+                               BTEqualStrategyNumber, F_INT4EQ,
+                               Int32GetDatum(0));
+
+       scan = systable_beginscan(depRel, DependReferenceIndexId, true,
+                                                         SnapshotNow, 3, key);
+
+       while (HeapTupleIsValid(tup = systable_getnext(scan)))
+       {
+               Form_pg_depend deprec = (Form_pg_depend) GETSTRUCT(tup);
+
+               /*
+                * We assume any internal dependency of an index on the constraint
+                * must be what we are looking for.  (The relkind test is just
+                * paranoia; there shouldn't be any such dependencies otherwise.)
+                */
+               if (deprec->classid == RelationRelationId &&
+                       deprec->objsubid == 0 &&
+                       deprec->deptype == DEPENDENCY_INTERNAL &&
+                       get_rel_relkind(deprec->objid) == RELKIND_INDEX)
+               {
+                       indexId = deprec->objid;
+                       break;
+               }
+       }
+
+       systable_endscan(scan);
+       heap_close(depRel, AccessShareLock);
+
+       return indexId;
+}
+
+
+/*
  * deparse_expression                  - General utility for deparsing expressions
  *
  * calls deparse_expression_pretty with all prettyPrinting disabled

diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index 309ce0a39456b8e5e3b475f7a2fb6fa0b3c6116c..3df1fc222a14a204d1009a545bdb04b4577b40f9 100644 (file)
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -1068,6 +1068,35 @@ get_rel_relkind(Oid relid)
                return '\0';
 }
 
+/*
+ * get_rel_tablespace
+ *
+ *             Returns the pg_tablespace OID associated with a given relation.
+ *
+ * Note: InvalidOid might mean either that we couldn't find the relation,
+ * or that it is in the database's default tablespace.
+ */
+Oid
+get_rel_tablespace(Oid relid)
+{
+       HeapTuple       tp;
+
+       tp = SearchSysCache(RELOID,
+                                               ObjectIdGetDatum(relid),
+                                               0, 0, 0);
+       if (HeapTupleIsValid(tp))
+       {
+               Form_pg_class reltup = (Form_pg_class) GETSTRUCT(tp);
+               Oid                     result;
+
+               result = reltup->reltablespace;
+               ReleaseSysCache(tp);
+               return result;
+       }
+       else
+               return InvalidOid;
+}
+
 
 /*                             ---------- TYPE CACHE ----------                                                 */
 

diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 5320d2ad06dfadcbcb68f6bfcc9506ce9f6c4563..5da3f3a37498d5b860c720eca7c7a3a0893c92cb 100644 (file)
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -66,6 +66,7 @@ extern char *get_rel_name(Oid relid);
 extern Oid     get_rel_namespace(Oid relid);
 extern Oid     get_rel_type_id(Oid relid);
 extern char get_rel_relkind(Oid relid);
+extern Oid     get_rel_tablespace(Oid relid);
 extern bool get_typisdefined(Oid typid);
 extern int16 get_typlen(Oid typid);
 extern bool get_typbyval(Oid typid);