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Diffstat (limited to 'src/backend/optimizer/util/keys.c')
| -rw-r--r-- | src/backend/optimizer/util/keys.c | 237 |
1 files changed, 0 insertions, 237 deletions
diff --git a/src/backend/optimizer/util/keys.c b/src/backend/optimizer/util/keys.c deleted file mode 100644 index c9a5a9b5ea9..00000000000 --- a/src/backend/optimizer/util/keys.c +++ /dev/null @@ -1,237 +0,0 @@ -/*------------------------------------------------------------------------- - * - * keys.c - * Key manipulation routines - * - * Copyright (c) 1994, Regents of the University of California - * - * - * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/util/Attic/keys.c,v 1.23 1999/07/15 22:39:31 momjian Exp $ - * - *------------------------------------------------------------------------- - */ -#include "postgres.h" - -#include "optimizer/keys.h" - - -static Expr *matching2_tlvar(int var, List *tlist, bool (*test) ()); -static bool equal_indexkey_var(int index_key, Var *var); - -/* - * 1. index key - * one of: - * attnum - * (attnum arrayindex) - * 2. path key - * (subkey1 ... subkeyN) - * where subkeyI is a var node - * note that the 'Keys field is a list of these - * 3. join key - * (outer_subkey inner_subkey) - * where each subkey is a var node - * 4. sort key - * one of: - * SortKey node - * number - * nil - * (may also refer to the 'SortKey field of a SortKey node, - * which looks exactly like an index key) - * - */ - -/* - * match_indexkey_operand - * Returns t iff an index key 'index_key' matches the given clause - * operand. - * - */ -bool -match_indexkey_operand(int indexkey, Var *operand, RelOptInfo *rel) -{ - if (IsA(operand, Var) && - (lfirsti(rel->relids) == operand->varno) && - equal_indexkey_var(indexkey, operand)) - return true; - else - return false; -} - -/* - * equal_indexkey_var - * Returns t iff an index key 'index_key' matches the corresponding - * fields of var node 'var'. - * - */ -static bool -equal_indexkey_var(int index_key, Var *var) -{ - if (index_key == var->varattno) - return true; - else - return false; -} - -/* - * extract_join_key - * Returns the subkey in a join key corresponding to the outer or inner - * relation. - * - */ -Var * -extract_join_key(JoinKey *jk, int outer_or_inner) -{ - Var *retval; - - switch (outer_or_inner) - { - case OUTER: - retval = jk->outer; - break; - case INNER: - retval = jk->inner; - break; - default: /* do nothing */ - elog(DEBUG, "extract_join_key with neither INNER or OUTER"); - retval = NULL; - } - return retval; -} - -/* - * pathkeys_match - * Returns t iff two sets of path keys are equivalent. They are - * equivalent if the first Var nodes match the second Var nodes. - * - * See the top of optimizer/path/pathkeys.c for a description of pathkeys. - * Each pathkey is ordered by its join order, so they not pre-ordered to - * match. We must search them ourselves. - * - * This gets called a lot, so it is optimized. - */ -bool -pathkeys_match(List *keys1, List *keys2, int *better_key) -{ - List *key1, - *key2; - bool key1_subsetof_key2 = true, - key2_subsetof_key1 = true; - - for (key1 = keys1, key2 = keys2; - key1 != NIL && key2 != NIL; - key1 = lnext(key1), key2 = lnext(key2)) - { - List *i; - - if (key1_subsetof_key2) - foreach(i, lfirst(key1)) - { - Var *subkey = lfirst(i); - - if (!member(subkey, lfirst(key2))) - { - key1_subsetof_key2 = false; - break; - } - } - - if (key2_subsetof_key1) - foreach(i, lfirst(key2)) - { - Var *subkey = lfirst(i); - - if (!member(subkey, lfirst(key1))) - { - key2_subsetof_key1 = false; - break; - } - } - if (!key1_subsetof_key2 && !key2_subsetof_key1) - break; /* no need to continue comparisons. */ - } - - if (!key1_subsetof_key2 && !key2_subsetof_key1) - { - *better_key = 0; - return false; - } - if (key1_subsetof_key2 && !key2_subsetof_key1) - { - *better_key = 2; - return true; - } - if (!key1_subsetof_key2 && key2_subsetof_key1) - { - *better_key = 1; - return true; - } - - *better_key = 0; - return true; - -} - -/* - * collect_index_pathkeys - * Creates a list of subkeys by retrieving var nodes corresponding to - * each index key in 'index_keys' from the relation's target list - * 'tlist'. If the key is not in the target list, the key is irrelevant - * and is thrown away. The returned subkey list is of the form: - * ((var1) (var2) ... (varn)) - * - * 'index_keys' is a list of index keys - * 'tlist' is a relation target list - * - * Returns the list of cons'd subkeys. - * - */ -/* This function is identical to matching_tlvar and tlistentry_member. - * They should be merged. - */ -static Expr * -matching2_tlvar(int var, List *tlist, bool (*test) ()) -{ - TargetEntry *tlentry = NULL; - - if (var) - { - List *temp; - - foreach(temp, tlist) - { - if ((*test) (var, get_expr(lfirst(temp)))) - { - tlentry = lfirst(temp); - break; - } - } - } - - if (tlentry) - return (Expr *) get_expr(tlentry); - else - return (Expr *) NULL; -} - - -List * -collect_index_pathkeys(int *index_keys, List *tlist) -{ - List *retval = NIL; - - Assert(index_keys != NULL); - - while (index_keys[0] != 0) - { - Expr *mvar; - - mvar = matching2_tlvar(index_keys[0], - tlist, - equal_indexkey_var); - if (mvar) - retval = lappend(retval, lcons(mvar, NIL)); - index_keys++; - } - return retval; -} |