diff options
Diffstat (limited to 'src/backend/optimizer/util/plancat.c')
| -rw-r--r-- | src/backend/optimizer/util/plancat.c | 105 |
1 files changed, 66 insertions, 39 deletions
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c index 36223be93fd..3f4fe661717 100644 --- a/src/backend/optimizer/util/plancat.c +++ b/src/backend/optimizer/util/plancat.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/util/plancat.c,v 1.83 2003/05/28 16:03:56 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/util/plancat.c,v 1.84 2003/06/29 23:05:04 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -26,6 +26,7 @@ #include "nodes/makefuncs.h" #include "optimizer/clauses.h" #include "optimizer/plancat.h" +#include "optimizer/tlist.h" #include "parser/parsetree.h" #include "rewrite/rewriteManip.h" #include "utils/builtins.h" @@ -44,7 +45,8 @@ * Given the Oid of the relation, return the following info into fields * of the RelOptInfo struct: * - * varlist list of physical columns (expressed as Vars) + * min_attr lowest valid AttrNumber + * max_attr highest valid AttrNumber * indexlist list of IndexOptInfos for relation's indexes * pages number of pages * tuples number of tuples @@ -52,49 +54,15 @@ void get_relation_info(Oid relationObjectId, RelOptInfo *rel) { - Relation relation; Index varno = rel->relid; + Relation relation; bool hasindex; - List *varlist = NIL; List *indexinfos = NIL; - int attrno, - numattrs; relation = heap_open(relationObjectId, AccessShareLock); - /* - * Make list of physical Vars. But if there are any dropped columns, - * punt and set varlist to NIL. (XXX Ideally we would like to include - * dropped columns so that the varlist models the physical tuples - * of the relation. However this creates problems for ExecTypeFromTL, - * which may be asked to build a tupdesc for a tlist that includes vars - * of no-longer-existent types. In theory we could dig out the required - * info from the pg_attribute entries of the relation, but that data is - * not readily available to ExecTypeFromTL. For now, punt and don't - * apply the physical-tlist optimization when there are dropped cols.) - */ - numattrs = RelationGetNumberOfAttributes(relation); - - for (attrno = 1; attrno <= numattrs; attrno++) - { - Form_pg_attribute att_tup = relation->rd_att->attrs[attrno - 1]; - - if (att_tup->attisdropped) - { - /* found a dropped col, so punt */ - varlist = NIL; - break; - } - - varlist = lappend(varlist, - makeVar(varno, - attrno, - att_tup->atttypid, - att_tup->atttypmod, - 0)); - } - - rel->varlist = varlist; + rel->min_attr = FirstLowInvalidHeapAttributeNumber + 1; + rel->max_attr = RelationGetNumberOfAttributes(relation); /* * Make list of indexes. Ignore indexes on system catalogs if told to. @@ -200,6 +168,65 @@ get_relation_info(Oid relationObjectId, RelOptInfo *rel) } /* + * build_physical_tlist + * + * Build a targetlist consisting of exactly the relation's user attributes, + * in order. The executor can special-case such tlists to avoid a projection + * step at runtime, so we use such tlists preferentially for scan nodes. + * + * Exception: if there are any dropped columns, we punt and return NIL. + * Ideally we would like to handle the dropped-column case too. However this + * creates problems for ExecTypeFromTL, which may be asked to build a tupdesc + * for a tlist that includes vars of no-longer-existent types. In theory we + * could dig out the required info from the pg_attribute entries of the + * relation, but that data is not readily available to ExecTypeFromTL. + * For now, we don't apply the physical-tlist optimization when there are + * dropped cols. + */ +List * +build_physical_tlist(Query *root, RelOptInfo *rel) +{ + Index varno = rel->relid; + RangeTblEntry *rte = rt_fetch(varno, root->rtable); + Relation relation; + FastList tlist; + int attrno, + numattrs; + + FastListInit(&tlist); + + Assert(rte->rtekind == RTE_RELATION); + + relation = heap_open(rte->relid, AccessShareLock); + + numattrs = RelationGetNumberOfAttributes(relation); + + for (attrno = 1; attrno <= numattrs; attrno++) + { + Form_pg_attribute att_tup = relation->rd_att->attrs[attrno - 1]; + + if (att_tup->attisdropped) + { + /* found a dropped col, so punt */ + FastListInit(&tlist); + break; + } + + FastAppend(&tlist, + create_tl_element(makeVar(varno, + attrno, + att_tup->atttypid, + att_tup->atttypmod, + 0), + attrno)); + } + + heap_close(relation, AccessShareLock); + + return FastListValue(&tlist); +} + +/* * restriction_selectivity * * Returns the selectivity of a specified restriction operator clause. |