diff options
Diffstat (limited to 'src/backend/optimizer/path/pathkey.c')
| -rw-r--r-- | src/backend/optimizer/path/pathkey.c | 115 |
1 files changed, 56 insertions, 59 deletions
diff --git a/src/backend/optimizer/path/pathkey.c b/src/backend/optimizer/path/pathkey.c index 50196f03795..92b27a774b2 100644 --- a/src/backend/optimizer/path/pathkey.c +++ b/src/backend/optimizer/path/pathkey.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/path/Attic/pathkey.c,v 1.1 1999/02/18 19:58:52 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/path/Attic/pathkey.c,v 1.2 1999/02/19 02:05:15 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -27,9 +27,9 @@ static int match_pathkey_joinkeys(List *pathkey, List *joinkeys, - int which_subkey); + int outer_or_inner); static bool every_func(List *joinkeys, List *pathkey, - int which_subkey); + int outer_or_inner); static List *new_join_pathkey(List *subkeys, List *considered_subkeys, List *join_rel_tlist, List *joinclauses); static List *new_matching_subkeys(Var *subkey, List *considered_subkeys, @@ -54,7 +54,7 @@ static List *new_matching_subkeys(Var *subkey, List *considered_subkeys, * ( (outer inner) (outer inner) ... ) * 'joinclauses' is a list of clauses corresponding to the join keys in * 'joinkeys' - * 'which_subkey' is a flag that selects the desired subkey of a join key + * 'outer_or_inner' is a flag that selects the desired subkey of a join key * in 'joinkeys' * * Returns the join keys and corresponding join clauses in a list if all @@ -72,7 +72,7 @@ List * match_pathkeys_joinkeys(List *pathkeys, List *joinkeys, List *joinclauses, - int which_subkey, + int outer_or_inner, List **matchedJoinClausesPtr) { List *matched_joinkeys = NIL; @@ -84,19 +84,17 @@ match_pathkeys_joinkeys(List *pathkeys, foreach(i, pathkeys) { pathkey = lfirst(i); - matched_joinkey_index = match_pathkey_joinkeys(pathkey, joinkeys, which_subkey); + matched_joinkey_index = match_pathkey_joinkeys(pathkey, joinkeys, + outer_or_inner); if (matched_joinkey_index != -1) { List *xjoinkey = nth(matched_joinkey_index, joinkeys); List *joinclause = nth(matched_joinkey_index, joinclauses); - /* XXX was "push" function */ - matched_joinkeys = lappend(matched_joinkeys, xjoinkey); - matched_joinkeys = nreverse(matched_joinkeys); + matched_joinkeys = lcons(xjoinkey, matched_joinkeys); + matched_joinclauses = lcons(joinclause, matched_joinclauses); - matched_joinclauses = lappend(matched_joinclauses, joinclause); - matched_joinclauses = nreverse(matched_joinclauses); joinkeys = LispRemove(xjoinkey, joinkeys); } else @@ -111,6 +109,7 @@ match_pathkeys_joinkeys(List *pathkeys, return nreverse(matched_joinkeys); } + /* * match_pathkey_joinkeys * Returns the 0-based index into 'joinkeys' of the first joinkey whose @@ -119,7 +118,7 @@ match_pathkeys_joinkeys(List *pathkeys, static int match_pathkey_joinkeys(List *pathkey, List *joinkeys, - int which_subkey) + int outer_or_inner) { Var *path_subkey; int pos; @@ -135,7 +134,7 @@ match_pathkey_joinkeys(List *pathkey, { jk = (JoinKey *) lfirst(x); if (var_equal(path_subkey, - extract_join_subkey(jk, which_subkey))) + extract_join_key(jk, outer_or_inner))) return pos; pos++; } @@ -143,6 +142,7 @@ match_pathkey_joinkeys(List *pathkey, return -1; /* no index found */ } + /* * match_paths_joinkeys * Attempts to find a path in 'paths' whose keys match a set of join @@ -159,53 +159,16 @@ match_pathkey_joinkeys(List *pathkey, * must correspond * 'paths' is a list of(inner) paths which are to be matched against * each join key in 'joinkeys' - * 'which_subkey' is a flag that selects the desired subkey of a join key + * 'outer_or_inner' is a flag that selects the desired subkey of a join key * in 'joinkeys' * - * Returns the matching path node if one exists, nil otherwise. - */ -static bool -every_func(List *joinkeys, List *pathkey, int which_subkey) -{ - JoinKey *xjoinkey; - Var *temp; - Var *tempkey = NULL; - bool found = false; - List *i = NIL; - List *j = NIL; - - foreach(i, joinkeys) - { - xjoinkey = (JoinKey *) lfirst(i); - found = false; - foreach(j, pathkey) - { - temp = (Var *) lfirst((List *) lfirst(j)); - if (temp == NULL) - continue; - tempkey = extract_join_subkey(xjoinkey, which_subkey); - if (var_equal(tempkey, temp)) - { - found = true; - break; - } - } - if (found == false) - return false; - } - return found; -} - - -/* - * match_paths_joinkeys - - * find the cheapest path that matches the join keys + * Find the cheapest path that matches the join keys */ Path * match_paths_joinkeys(List *joinkeys, PathOrder *ordering, List *paths, - int which_subkey) + int outer_or_inner) { Path *matched_path = NULL; bool key_match = false; @@ -216,13 +179,12 @@ match_paths_joinkeys(List *joinkeys, Path *path = (Path *) lfirst(i); int better_sort; - key_match = every_func(joinkeys, path->pathkeys, which_subkey); + key_match = every_func(joinkeys, path->pathkeys, outer_or_inner); if (pathorder_match(ordering, path->pathorder, &better_sort) && better_sort == 0 && length(joinkeys) == length(path->pathkeys) && key_match) { - if (matched_path) { if (path->path_cost < matched_path->path_cost) @@ -236,7 +198,6 @@ match_paths_joinkeys(List *joinkeys, } - /* * extract_path_keys * Builds a subkey list for a path by pulling one of the subkeys from @@ -245,7 +206,7 @@ match_paths_joinkeys(List *joinkeys, * * 'joinkeys' is a list of join key pairs * 'tlist' is a relation target list - * 'which_subkey' is a flag that selects the desired subkey of a join key + * 'outer_or_inner' is a flag that selects the desired subkey of a join key * in 'joinkeys' * * Returns a list of pathkeys: ((tlvar1)(tlvar2)...(tlvarN)). @@ -254,7 +215,7 @@ match_paths_joinkeys(List *joinkeys, List * extract_path_keys(List *joinkeys, List *tlist, - int which_subkey) + int outer_or_inner) { List *pathkeys = NIL; List *jk; @@ -269,7 +230,7 @@ extract_path_keys(List *joinkeys, /* * find the right Var in the target list for this key */ - var = (Var *) extract_join_subkey(jkey, which_subkey); + var = (Var *) extract_join_key(jkey, outer_or_inner); key = (Var *) matching_tlist_var(var, tlist); /* @@ -291,6 +252,42 @@ extract_path_keys(List *joinkeys, } +/* + * every_func + */ +static bool +every_func(List *joinkeys, List *pathkey, int outer_or_inner) +{ + JoinKey *xjoinkey; + Var *temp; + Var *tempkey = NULL; + bool found = false; + List *i = NIL; + List *j = NIL; + + foreach(i, joinkeys) + { + xjoinkey = (JoinKey *) lfirst(i); + found = false; + foreach(j, pathkey) + { + temp = (Var *) lfirst((List *) lfirst(j)); + if (temp == NULL) + continue; + tempkey = extract_join_key(xjoinkey, outer_or_inner); + if (var_equal(tempkey, temp)) + { + found = true; + break; + } + } + if (found == false) + return false; + } + return found; +} + + /**************************************************************************** * NEW PATHKEY FORMATION ****************************************************************************/ |