Convert planner's AggInfo and AggTransInfo structs to proper Nodes.

This is mostly just to get outfuncs.c support for them, so that
the agginfos and aggtransinfos lists can be dumped when dumping
the contents of PlannerInfo.

While here, improve some related comments; notably, clean up
obsolete comments left over from when preprocess_minmax_aggregates
had to make its own scan of the query tree.

Discussion: https://postgr.es/m/742479.1658160504@sss.pgh.pa.us

diff --git a/src/backend/optimizer/plan/planagg.c b/src/backend/optimizer/plan/planagg.c
index 9330908cbf1ba06a8cb7f7a97c0bd8169ef4940f..e0e357960f2378546bf8382fbb649bc281df2f4a 100644 (file)
--- a/src/backend/optimizer/plan/planagg.c
+++ b/src/backend/optimizer/plan/planagg.c
@@ -137,8 +137,8 @@ preprocess_minmax_aggregates(PlannerInfo *root)
        return;
 
    /*
-    * Scan the tlist and HAVING qual to find all the aggregates and verify
-    * all are MIN/MAX aggregates.  Stop as soon as we find one that isn't.
+    * Examine all the aggregates and verify all are MIN/MAX aggregates.  Stop
+    * as soon as we find one that isn't.
     */
    aggs_list = NIL;
    if (!can_minmax_aggs(root, &aggs_list))
@@ -227,24 +227,24 @@ preprocess_minmax_aggregates(PlannerInfo *root)
 
 /*
  * can_minmax_aggs
- *     Walk through all the aggregates in the query, and check
- *     if they are all MIN/MAX aggregates.  If so, build a list of the
- *     distinct aggregate calls in the tree.
+ *     Examine all the aggregates in the query, and check if they are
+ *     all MIN/MAX aggregates.  If so, build a list of MinMaxAggInfo
+ *     nodes for them.
  *
  * Returns false if a non-MIN/MAX aggregate is found, true otherwise.
- *
- * This does not descend into subqueries, and so should be used only after
- * reduction of sublinks to subplans.  There mustn't be outer-aggregate
- * references either.
  */
 static bool
 can_minmax_aggs(PlannerInfo *root, List **context)
 {
    ListCell   *lc;
 
+   /*
+    * This function used to have to scan the query for itself, but now we can
+    * just thumb through the AggInfo list made by preprocess_aggrefs.
+    */
    foreach(lc, root->agginfos)
    {
-       AggInfo    *agginfo = (AggInfo *) lfirst(lc);
+       AggInfo    *agginfo = lfirst_node(AggInfo, lc);
        Aggref     *aggref = agginfo->representative_aggref;
        Oid         aggsortop;
        TargetEntry *curTarget;

diff --git a/src/backend/optimizer/prep/prepagg.c b/src/backend/optimizer/prep/prepagg.c
index 404a5f1dac80abac8e751dc164904e0a37f78f1e..5b12937eada4c9c3aa57a89a6012661015245ff1 100644 (file)
--- a/src/backend/optimizer/prep/prepagg.c
+++ b/src/backend/optimizer/prep/prepagg.c
@@ -223,13 +223,13 @@ preprocess_aggref(Aggref *aggref, PlannerInfo *root)
    aggno = find_compatible_agg(root, aggref, &same_input_transnos);
    if (aggno != -1)
    {
-       AggInfo    *agginfo = list_nth(root->agginfos, aggno);
+       AggInfo    *agginfo = list_nth_node(AggInfo, root->agginfos, aggno);
 
        transno = agginfo->transno;
    }
    else
    {
-       AggInfo    *agginfo = palloc(sizeof(AggInfo));
+       AggInfo    *agginfo = makeNode(AggInfo);
 
        agginfo->finalfn_oid = aggfinalfn;
        agginfo->representative_aggref = aggref;
@@ -266,7 +266,7 @@ preprocess_aggref(Aggref *aggref, PlannerInfo *root)
                                        same_input_transnos);
        if (transno == -1)
        {
-           AggTransInfo *transinfo = palloc(sizeof(AggTransInfo));
+           AggTransInfo *transinfo = makeNode(AggTransInfo);
 
            transinfo->args = aggref->args;
            transinfo->aggfilter = aggref->aggfilter;
@@ -381,7 +381,7 @@ find_compatible_agg(PlannerInfo *root, Aggref *newagg,
    aggno = -1;
    foreach(lc, root->agginfos)
    {
-       AggInfo    *agginfo = (AggInfo *) lfirst(lc);
+       AggInfo    *agginfo = lfirst_node(AggInfo, lc);
        Aggref     *existingRef;
 
        aggno++;
@@ -452,7 +452,9 @@ find_compatible_trans(PlannerInfo *root, Aggref *newagg, bool shareable,
    foreach(lc, transnos)
    {
        int         transno = lfirst_int(lc);
-       AggTransInfo *pertrans = (AggTransInfo *) list_nth(root->aggtransinfos, transno);
+       AggTransInfo *pertrans = list_nth_node(AggTransInfo,
+                                              root->aggtransinfos,
+                                              transno);
 
        /*
         * if the transfns or transition state types are not the same then the
@@ -541,7 +543,7 @@ get_agg_clause_costs(PlannerInfo *root, AggSplit aggsplit, AggClauseCosts *costs
 
    foreach(lc, root->aggtransinfos)
    {
-       AggTransInfo *transinfo = (AggTransInfo *) lfirst(lc);
+       AggTransInfo *transinfo = lfirst_node(AggTransInfo, lc);
 
        /*
         * Add the appropriate component function execution costs to
@@ -645,7 +647,7 @@ get_agg_clause_costs(PlannerInfo *root, AggSplit aggsplit, AggClauseCosts *costs
 
    foreach(lc, root->agginfos)
    {
-       AggInfo    *agginfo = (AggInfo *) lfirst(lc);
+       AggInfo    *agginfo = lfirst_node(AggInfo, lc);
        Aggref     *aggref = agginfo->representative_aggref;
 
        /*

diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index 69ba254372dd98ce2aaf7a595653d35e84f7ae18..e650af5ff29f5a1c1365f92f9a9101bbba5f98b8 100644 (file)
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -442,15 +442,15 @@ struct PlannerInfo
     * Information about aggregates. Filled by preprocess_aggrefs().
     */
    /* AggInfo structs */
-   List       *agginfos pg_node_attr(read_write_ignore);
+   List       *agginfos;
    /* AggTransInfo structs */
-   List       *aggtransinfos pg_node_attr(read_write_ignore);
-   /* number w/ DISTINCT/ORDER BY/WITHIN GROUP */
-   int         numOrderedAggs pg_node_attr(read_write_ignore);
+   List       *aggtransinfos;
+   /* number of aggs with DISTINCT/ORDER BY/WITHIN GROUP */
+   int         numOrderedAggs;
    /* does any agg not support partial mode? */
-   bool        hasNonPartialAggs pg_node_attr(read_write_ignore);
+   bool        hasNonPartialAggs;
    /* is any partial agg non-serializable? */
-   bool        hasNonSerialAggs pg_node_attr(read_write_ignore);
+   bool        hasNonSerialAggs;
 
    /*
     * These fields are used only when hasRecursion is true:
@@ -3121,6 +3121,10 @@ typedef struct JoinCostWorkspace
  */
 typedef struct AggInfo
 {
+   pg_node_attr(no_copy_equal, no_read)
+
+   NodeTag     type;
+
    /*
     * Link to an Aggref expr this state value is for.
     *
@@ -3129,6 +3133,7 @@ typedef struct AggInfo
     */
    Aggref     *representative_aggref;
 
+   /* Transition state number for this aggregate */
    int         transno;
 
    /*
@@ -3137,9 +3142,8 @@ typedef struct AggInfo
     */
    bool        shareable;
 
-   /* Oid of the final function or InvalidOid */
+   /* Oid of the final function, or InvalidOid if none */
    Oid         finalfn_oid;
-
 } AggInfo;
 
 /*
@@ -3151,34 +3155,40 @@ typedef struct AggInfo
  */
 typedef struct AggTransInfo
 {
+   pg_node_attr(no_copy_equal, no_read)
+
+   NodeTag     type;
+
+   /* Inputs for this transition state */
    List       *args;
    Expr       *aggfilter;
 
    /* Oid of the state transition function */
    Oid         transfn_oid;
 
-   /* Oid of the serialization function or InvalidOid */
+   /* Oid of the serialization function, or InvalidOid if none */
    Oid         serialfn_oid;
 
-   /* Oid of the deserialization function or InvalidOid */
+   /* Oid of the deserialization function, or InvalidOid if none */
    Oid         deserialfn_oid;
 
-   /* Oid of the combine function or InvalidOid */
+   /* Oid of the combine function, or InvalidOid if none */
    Oid         combinefn_oid;
 
    /* Oid of state value's datatype */
    Oid         aggtranstype;
+
+   /* Additional data about transtype */
    int32       aggtranstypmod;
    int         transtypeLen;
    bool        transtypeByVal;
+
+   /* Space-consumption estimate */
    int32       aggtransspace;
 
-   /*
-    * initial value from pg_aggregate entry
-    */
-   Datum       initValue;
+   /* Initial value from pg_aggregate entry */
+   Datum       initValue pg_node_attr(read_write_ignore);
    bool        initValueIsNull;
-
 } AggTransInfo;
 
 #endif                         /* PATHNODES_H */