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pathkeys fixes
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0ff2733355
commit
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@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/nodes/print.c,v 1.22 1999/02/13 23:16:00 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/nodes/print.c,v 1.23 1999/02/20 19:02:40 momjian Exp $
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*
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* HISTORY
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* AUTHOR DATE MAJOR EVENT
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@ -213,20 +213,28 @@ print_expr(Node *expr, List *rtable)
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/*
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* print_pathkeys -
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* temporary here. where is keys list of lists
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* pathkeys list of list of Var's
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*/
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void
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print_pathkeys(List *pathkeys, List *rtable)
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{
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List *k;
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List *i, *k;
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printf("(");
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foreach(k, pathkeys)
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foreach(i, pathkeys)
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{
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Node *var = lfirst((List *) lfirst(k));
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List pathkey = lfirst(i));
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print_expr(var, rtable);
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if (lnext(k))
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printf("(");
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foreach(k, pathkey)
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{
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Node *var = lfirst(k);
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print_expr(var, rtable);
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if (lnext(k))
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printf(", ");
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}
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printf(") ");
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if (lnext(i))
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printf(", ");
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}
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printf(")\n");
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@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/optimizer/path/pathkeys.c,v 1.4 1999/02/20 18:01:01 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/optimizer/path/pathkeys.c,v 1.5 1999/02/20 19:02:41 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -54,7 +54,19 @@ static List *new_matching_subkeys(Var *subkey, List *considered_subkeys,
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* { {tab1.col1, tab2.col1} }. This allows future joins to use either Var
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* as a pre-sorted key to prevent Mergejoins from having to re-sort the Path.
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* They are equal, so they are both primary sort keys. This is why pathkeys
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* is a List of Lists. -- bjm
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* is a List of Lists.
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*
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* For multi-key sorts, if the outer is sorted by a multi-key index, the
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* multi-key index remains after the join. If the inner has a multi-key
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* sort, only the primary key of the inner is added to the result.
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* Mergejoins only join on the primary key. Currently, non-primary keys
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* in the pathkeys List are of limited value.
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*
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* HashJoin has similar functionality. NestJoin does not perform sorting,
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* and allows non-equajoins, so it does not allow useful pathkeys.
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*
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* -- bjm
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*
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*/
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/****************************************************************************
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@ -92,10 +104,10 @@ static List *new_matching_subkeys(Var *subkey, List *considered_subkeys,
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*/
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List *
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order_joinkeys_by_pathkeys(List *pathkeys,
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List *joinkeys,
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List *joinclauses,
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int outer_or_inner,
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List **matchedJoinClausesPtr)
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List *joinkeys,
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List *joinclauses,
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int outer_or_inner,
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List **matchedJoinClausesPtr)
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{
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List *matched_joinkeys = NIL;
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List *matched_joinclauses = NIL;
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@ -103,6 +115,10 @@ order_joinkeys_by_pathkeys(List *pathkeys,
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List *i = NIL;
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int matched_joinkey_index = -1;
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/*
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* Reorder the joinkeys by picking out one that matches each pathkey,
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* and create a new joinkey/joinclause list in pathkey order
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*/
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foreach(i, pathkeys)
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{
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pathkey = lfirst(i);
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@ -118,10 +134,18 @@ order_joinkeys_by_pathkeys(List *pathkeys,
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matched_joinclauses = lappend(matched_joinclauses, joinclause);
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}
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else
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{
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/* A pathkey could not be matched. */
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break;
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}
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/*
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* Did we fail to match all the joinkeys?
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* Extra pathkeys are no problem.
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*/
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if (length(joinkeys) != length(matched_joinkeys))
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{
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*matchedJoinClausesPtr = NIL;
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return NIL;
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}
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}
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*matchedJoinClausesPtr = matched_joinclauses;
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@ -133,6 +157,8 @@ order_joinkeys_by_pathkeys(List *pathkeys,
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* match_pathkey_joinkeys
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* Returns the 0-based index into 'joinkeys' of the first joinkey whose
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* outer or inner subkey matches any subkey of 'pathkey'.
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*
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* All these keys are equivalent, so any of them can match. See above.
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*/
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static int
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match_pathkey_joinkeys(List *pathkey,
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@ -141,8 +167,7 @@ match_pathkey_joinkeys(List *pathkey,
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{
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Var *path_subkey;
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int pos;
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List *i = NIL;
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List *x = NIL;
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List *i, *x;
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JoinKey *jk;
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foreach(i, pathkey)
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@ -152,8 +177,7 @@ match_pathkey_joinkeys(List *pathkey,
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foreach(x, joinkeys)
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{
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jk = (JoinKey *) lfirst(x);
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if (var_equal(path_subkey,
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extract_join_key(jk, outer_or_inner)))
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if (var_equal(path_subkey, extract_join_key(jk, outer_or_inner)))
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return pos;
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pos++;
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}
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@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.38 1999/02/20 18:01:02 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.39 1999/02/20 19:02:42 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -205,7 +205,7 @@ better_path(Path *new_path, List *unique_paths, bool *is_new)
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{
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/*
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* Replace pathkeys that match exactly, {{1,2}}, {{1,2}}
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* Replace pathkeys {{1,2}}with {{1,2,3}}} if the latter is not
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* Replace pathkeys {{1,2}} with {{1,2,3}}} if the latter is not
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* more expensive and replace unordered path with ordered
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* path if it is not more expensive. Favor sorted keys
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* over unsorted keys in the same way.
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@ -6,7 +6,7 @@
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*
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* Copyright (c) 1994, Regents of the University of California
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*
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* $Id: relation.h,v 1.27 1999/02/20 16:28:20 momjian Exp $
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* $Id: relation.h,v 1.28 1999/02/20 19:02:43 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -142,8 +142,7 @@ typedef struct Path
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PathOrder *pathorder;
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List *pathkeys; /*
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* This is a List of List of Var nodes.
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List *pathkeys; /* This is a List of List of Var nodes.
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* See the top of optimizer/path/pathkeys.c
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* for more information.
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*/
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