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Redesign DISTINCT ON as discussed in pgsql-sql 1/25/00: syntax is now
SELECT DISTINCT ON (expr [, expr ...]) targetlist ... and there is a check to make sure that the user didn't specify an ORDER BY that's incompatible with the DISTINCT operation. Reimplement nodeUnique and nodeGroup to use the proper datatype-specific equality function for each column being compared --- they used to do bitwise comparisons or convert the data to text strings and strcmp(). (To add insult to injury, they'd look up the conversion functions once for each tuple...) Parse/plan representation of DISTINCT is now a list of SortClause nodes. initdb forced by querytree change...
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@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.80 2000/01/26 05:56:32 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.81 2000/01/27 18:11:28 tgl Exp $
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*
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* NOTES
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* Most of the read functions for plan nodes are tested. (In fact, they
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@ -111,12 +111,8 @@ _readQuery()
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token = lsptok(NULL, &length); /* get unionall */
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local_node->unionall = (token[0] == 't') ? true : false;
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token = lsptok(NULL, &length); /* skip :uniqueFlag */
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token = lsptok(NULL, &length); /* get uniqueFlag */
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if (length == 0)
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local_node->uniqueFlag = NULL;
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else
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local_node->uniqueFlag = debackslash(token, length);
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token = lsptok(NULL, &length); /* skip :distinctClause */
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local_node->distinctClause = nodeRead(true);
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token = lsptok(NULL, &length); /* skip :sortClause */
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local_node->sortClause = nodeRead(true);
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@ -624,33 +620,6 @@ _readAgg()
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return local_node;
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}
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/* ----------------
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* _readUnique
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*
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* For some reason, unique is a subclass of Noname.
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*/
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static Unique *
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_readUnique()
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{
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Unique *local_node;
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char *token;
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int length;
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local_node = makeNode(Unique);
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_getPlan((Plan *) local_node);
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token = lsptok(NULL, &length); /* eat :nonameid */
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token = lsptok(NULL, &length); /* get :nonameid */
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local_node->nonameid = atol(token);
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token = lsptok(NULL, &length); /* eat :keycount */
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token = lsptok(NULL, &length); /* get :keycount */
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local_node->keycount = atoi(token);
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return local_node;
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}
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/* ----------------
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* _readHash
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*
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@ -1847,8 +1816,6 @@ parsePlanString(void)
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return_value = _readSubLink();
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else if (length == 3 && strncmp(token, "AGG", length) == 0)
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return_value = _readAgg();
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else if (length == 6 && strncmp(token, "UNIQUE", length) == 0)
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return_value = _readUnique();
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else if (length == 4 && strncmp(token, "HASH", length) == 0)
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return_value = _readHash();
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else if (length == 6 && strncmp(token, "RESDOM", length) == 0)
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