diff options
Diffstat (limited to 'src/backend/optimizer/path/allpaths.c')
| -rw-r--r-- | src/backend/optimizer/path/allpaths.c | 69 |
1 files changed, 40 insertions, 29 deletions
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index 243ff7c5a72..afb3259e736 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 1.73 2001/05/08 17:25:28 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.74 2001/05/20 20:28:18 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -35,8 +35,8 @@ static void set_base_rel_pathlists(Query *root); static void set_plain_rel_pathlist(Query *root, RelOptInfo *rel, RangeTblEntry *rte); static void set_inherited_rel_pathlist(Query *root, RelOptInfo *rel, - RangeTblEntry *rte, - List *inheritlist); + Index rti, RangeTblEntry *rte, + List *inheritlist); static RelOptInfo *make_one_rel_by_joins(Query *root, int levels_needed, List *initial_rels); @@ -69,7 +69,7 @@ make_one_rel(Query *root) rel = make_fromexpr_rel(root, root->jointree); /* - * The result should join all the query's rels. + * The result should join all the query's base rels. */ Assert(length(rel->relids) == length(root->base_rel_list)); @@ -190,10 +190,11 @@ set_base_rel_pathlists(Query *root) /* Select cheapest path (pretty easy in this case...) */ set_cheapest(rel); } - else if ((inheritlist = expand_inherted_rtentry(root, rti)) != NIL) + else if ((inheritlist = expand_inherted_rtentry(root, rti, true)) + != NIL) { /* Relation is root of an inheritance tree, process specially */ - set_inherited_rel_pathlist(root, rel, rte, inheritlist); + set_inherited_rel_pathlist(root, rel, rti, rte, inheritlist); } else { @@ -210,8 +211,6 @@ set_base_rel_pathlists(Query *root) static void set_plain_rel_pathlist(Query *root, RelOptInfo *rel, RangeTblEntry *rte) { - List *indices = find_secondary_indexes(rte->relid); - /* Mark rel with estimated output rows, width, etc */ set_baserel_size_estimates(root, rel); @@ -230,13 +229,9 @@ set_plain_rel_pathlist(Query *root, RelOptInfo *rel, RangeTblEntry *rte) create_tidscan_paths(root, rel); /* Consider index paths for both simple and OR index clauses */ - create_index_paths(root, rel, indices); + create_index_paths(root, rel); - /* - * Note: create_or_index_paths depends on create_index_paths to have - * marked OR restriction clauses with relevant indices; this is why it - * doesn't need to be given the list of indices. - */ + /* create_index_paths must be done before create_or_index_paths */ create_or_index_paths(root, rel, rel->baserestrictinfo); /* Now find the cheapest of the paths for this rel */ @@ -248,14 +243,26 @@ set_plain_rel_pathlist(Query *root, RelOptInfo *rel, RangeTblEntry *rte) * Build access paths for a inheritance tree rooted at rel * * inheritlist is a list of RT indexes of all tables in the inheritance tree, - * including the parent itself. Note we will not come here unless there's - * at least one child in addition to the parent. + * including a duplicate of the parent itself. Note we will not come here + * unless there's at least one child in addition to the parent. + * + * NOTE: the passed-in rel and RTE will henceforth represent the appended + * result of the whole inheritance tree. The members of inheritlist represent + * the individual tables --- in particular, the inheritlist member that is a + * duplicate of the parent RTE represents the parent table alone. + * We will generate plans to scan the individual tables that refer to + * the inheritlist RTEs, whereas Vars elsewhere in the plan tree that + * refer to the original RTE are taken to refer to the append output. + * In particular, this means we have separate RelOptInfos for the parent + * table and for the append output, which is a good thing because they're + * not the same size. */ static void -set_inherited_rel_pathlist(Query *root, RelOptInfo *rel, RangeTblEntry *rte, +set_inherited_rel_pathlist(Query *root, RelOptInfo *rel, + Index rti, RangeTblEntry *rte, List *inheritlist) { - int parentRTindex = lfirsti(rel->relids); + int parentRTindex = rti; Oid parentOID = rte->relid; List *subpaths = NIL; List *il; @@ -268,7 +275,15 @@ set_inherited_rel_pathlist(Query *root, RelOptInfo *rel, RangeTblEntry *rte, elog(ERROR, "SELECT FOR UPDATE is not supported for inherit queries"); /* - * Recompute size estimates for whole inheritance tree + * The executor will check the parent table's access permissions when it + * examines the parent's inheritlist entry. There's no need to check + * twice, so turn off access check bits in the original RTE. + */ + rte->checkForRead = false; + rte->checkForWrite = false; + + /* + * Initialize to compute size estimates for whole inheritance tree */ rel->rows = 0; rel->width = 0; @@ -289,21 +304,17 @@ set_inherited_rel_pathlist(Query *root, RelOptInfo *rel, RangeTblEntry *rte, /* * Make a RelOptInfo for the child so we can do planning. Do NOT - * attach the RelOptInfo to the query's base_rel_list, however. - * - * NOTE: when childRTindex == parentRTindex, we create a second - * RelOptInfo for the same relation. This RelOptInfo will - * represent the parent table alone, whereas the original - * RelOptInfo represents the union of the inheritance tree - * members. + * attach the RelOptInfo to the query's base_rel_list, however, + * since the child is not part of the main join tree. Instead, + * the child RelOptInfo is added to other_rel_list. */ - childrel = make_base_rel(root, childRTindex); + childrel = build_other_rel(root, childRTindex); /* * Copy the parent's targetlist and restriction quals to the - * child, with attribute-number adjustment if needed. We don't + * child, with attribute-number adjustment as needed. We don't * bother to copy the join quals, since we can't do any joining - * here. + * of the individual tables. */ childrel->targetlist = (List *) adjust_inherited_attrs((Node *) rel->targetlist, |