Remove reltarget_has_non_vars flag.

Commit b12fd41c6 added a "reltarget_has_non_vars" field to RelOptInfo,
but failed to maintain it accurately.  Since its only purpose was to skip
calls to has_parallel_hazard() in the simple case where a rel's targetlist
is all Vars, and that call is really pretty cheap in that case anyway, it
seems like this is just a case of premature optimization.  Let's drop the
flag and do the calls unconditionally until it's proven that we need more
smarts here.

diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 2796e5353aea1add2da2eb238a4c8ae8a30830cb..c7b4153c0308becb4364c896b6c648d91e567722 100644 (file)
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -2083,7 +2083,6 @@ _outRelOptInfo(StringInfo str, const RelOptInfo *node)
    WRITE_BOOL_FIELD(consider_param_startup);
    WRITE_BOOL_FIELD(consider_parallel);
    WRITE_NODE_FIELD(reltarget);
-   WRITE_BOOL_FIELD(reltarget_has_non_vars);
    WRITE_NODE_FIELD(pathlist);
    WRITE_NODE_FIELD(ppilist);
    WRITE_NODE_FIELD(partial_pathlist);

diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index ff5e39c1aad70ad3f52153c324c1f7f8467e3667..cc8ba61bb0c9ce2ecbf400afcf12fad17f2483c5 100644 (file)
--- a/src/backend/optimizer/path/allpaths.c
+++ b/src/backend/optimizer/path/allpaths.c
@@ -613,12 +613,10 @@ set_rel_consider_parallel(PlannerInfo *root, RelOptInfo *rel,
        return;
 
    /*
-    * If the relation's outputs are not parallel-safe, we must give up. In
-    * the common case where the relation only outputs Vars, this check is
-    * very cheap; otherwise, we have to do more work.
+    * Likewise, if the relation's outputs are not parallel-safe, give up.
+    * (Usually, they're just Vars, but sometimes they're not.)
     */
-   if (rel->reltarget_has_non_vars &&
-       has_parallel_hazard((Node *) rel->reltarget->exprs, false))
+   if (has_parallel_hazard((Node *) rel->reltarget->exprs, false))
        return;
 
    /* We have a winner. */
@@ -984,7 +982,6 @@ set_append_rel_size(PlannerInfo *root, RelOptInfo *rel,
            adjust_appendrel_attrs(root,
                                   (Node *) rel->reltarget->exprs,
                                   appinfo);
-       childrel->reltarget_has_non_vars = rel->reltarget_has_non_vars;
 
        /*
         * We have to make child entries in the EquivalenceClass data

diff --git a/src/backend/optimizer/util/placeholder.c b/src/backend/optimizer/util/placeholder.c
index 5b85a4ddadcd14991b2550697fe8837bb6c83412..b210914b85391c1397762cb0f795a7c1f055c216 100644 (file)
--- a/src/backend/optimizer/util/placeholder.c
+++ b/src/backend/optimizer/util/placeholder.c
@@ -393,7 +393,6 @@ add_placeholders_to_base_rels(PlannerInfo *root)
 
            rel->reltarget->exprs = lappend(rel->reltarget->exprs,
                                            copyObject(phinfo->ph_var));
-           rel->reltarget_has_non_vars = true;
            /* reltarget's cost and width fields will be updated later */
        }
    }
@@ -428,7 +427,6 @@ add_placeholders_to_joinrel(PlannerInfo *root, RelOptInfo *joinrel,
                /* Yup, add it to the output */
                joinrel->reltarget->exprs = lappend(joinrel->reltarget->exprs,
                                                    phinfo->ph_var);
-               joinrel->reltarget_has_non_vars = true;
                joinrel->reltarget->width += phinfo->ph_width;
 
                /*

diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c
index 91cd2b506fb6a6eb8849e7b11d888d69f73b705d..ba185aec1a38ce6f2c3f66c7ba7a40adcc3a0409 100644 (file)
--- a/src/backend/optimizer/util/relnode.c
+++ b/src/backend/optimizer/util/relnode.c
@@ -109,7 +109,6 @@ build_simple_rel(PlannerInfo *root, int relid, RelOptKind reloptkind)
    rel->consider_parallel = false;     /* might get changed later */
    rel->rel_parallel_workers = -1;     /* set up in GetRelationInfo */
    rel->reltarget = create_empty_pathtarget();
-   rel->reltarget_has_non_vars = false;
    rel->pathlist = NIL;
    rel->ppilist = NIL;
    rel->partial_pathlist = NIL;
@@ -397,7 +396,6 @@ build_join_rel(PlannerInfo *root,
    joinrel->consider_param_startup = false;
    joinrel->consider_parallel = false;
    joinrel->reltarget = create_empty_pathtarget();
-   joinrel->reltarget_has_non_vars = false;
    joinrel->pathlist = NIL;
    joinrel->ppilist = NIL;
    joinrel->partial_pathlist = NIL;
@@ -520,8 +518,7 @@ build_join_rel(PlannerInfo *root,
     */
    if (inner_rel->consider_parallel && outer_rel->consider_parallel &&
        !has_parallel_hazard((Node *) restrictlist, false) &&
-       !(joinrel->reltarget_has_non_vars &&
-         has_parallel_hazard((Node *) joinrel->reltarget->exprs, false)))
+       !has_parallel_hazard((Node *) joinrel->reltarget->exprs, false))
        joinrel->consider_parallel = true;
 
    /*

diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h
index 7ca1e253b9eae8dd8e2834aec59b831778cbc114..cafd69622988714738a330bfc1e9999f4691a9e8 100644 (file)
--- a/src/include/nodes/relation.h
+++ b/src/include/nodes/relation.h
@@ -490,8 +490,6 @@ typedef struct RelOptInfo
 
    /* default result targetlist for Paths scanning this relation */
    struct PathTarget *reltarget;       /* list of Vars/Exprs, cost, width */
-   bool        reltarget_has_non_vars; /* true if any expression in
-                                        * PathTarget is a non-Var */
 
    /* materialization information */
    List       *pathlist;       /* Path structures */