diff options
Diffstat (limited to 'src/backend/optimizer/path/allpaths.c')
| -rw-r--r-- | src/backend/optimizer/path/allpaths.c | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index e6791dddd69..cd04af9f821 100644 --- a/src/backend/optimizer/path/allpaths.c +++ b/src/backend/optimizer/path/allpaths.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.102 2003/04/24 23:43:09 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.103 2003/06/29 23:05:04 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -235,6 +235,9 @@ set_inherited_rel_pathlist(Query *root, RelOptInfo *rel, RangeTblEntry *childrte; Oid childOID; RelOptInfo *childrel; + List *reltlist; + List *parentvars; + List *childvars; childrte = rt_fetch(childRTindex, root->rtable); childOID = childrte->relid; @@ -251,21 +254,24 @@ set_inherited_rel_pathlist(Query *root, RelOptInfo *rel, * Copy the parent's targetlist and restriction quals to the * child, with attribute-number adjustment as needed. We don't * bother to copy the join quals, since we can't do any joining of - * the individual tables. + * the individual tables. Also, we just zap attr_needed rather + * than trying to adjust it; it won't be looked at in the child. */ - childrel->targetlist = (List *) - adjust_inherited_attrs((Node *) rel->targetlist, + reltlist = FastListValue(&rel->reltargetlist); + reltlist = (List *) + adjust_inherited_attrs((Node *) reltlist, parentRTindex, parentOID, childRTindex, childOID); + FastListFromList(&childrel->reltargetlist, reltlist); + childrel->attr_needed = NULL; childrel->baserestrictinfo = (List *) adjust_inherited_attrs((Node *) rel->baserestrictinfo, parentRTindex, parentOID, childRTindex, childOID); - childrel->baserestrictcost = rel->baserestrictcost; /* * Now compute child access paths, and save the cheapest. @@ -274,10 +280,27 @@ set_inherited_rel_pathlist(Query *root, RelOptInfo *rel, subpaths = lappend(subpaths, childrel->cheapest_total_path); - /* Also update total size estimates */ + /* + * Propagate size information from the child back to the parent. + * For simplicity, we use the largest widths from any child as the + * parent estimates. + */ rel->rows += childrel->rows; if (childrel->width > rel->width) rel->width = childrel->width; + + childvars = FastListValue(&childrel->reltargetlist); + foreach(parentvars, FastListValue(&rel->reltargetlist)) + { + Var *parentvar = (Var *) lfirst(parentvars); + Var *childvar = (Var *) lfirst(childvars); + int parentndx = parentvar->varattno - rel->min_attr; + int childndx = childvar->varattno - childrel->min_attr; + + if (childrel->attr_widths[childndx] > rel->attr_widths[parentndx]) + rel->attr_widths[parentndx] = childrel->attr_widths[childndx]; + childvars = lnext(childvars); + } } /* |