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author | Thomas G. Lockhart <lockhart@fourpalms.org> | 2002-07-04 15:24:11 +0000 |
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committer | Thomas G. Lockhart <lockhart@fourpalms.org> | 2002-07-04 15:24:11 +0000 |
commit | 68d9fbeb5511d846ce3a6f66b8955d3ca55a4b76 (patch) | |
tree | 2c916fdd1c617a90fdd143e6f68ea9c48d19f296 /src/backend/nodes/outfuncs.c | |
parent | c7eea66c392cd3f5c914ed135d01a2e20ecb1f92 (diff) | |
download | postgresql-68d9fbeb5511d846ce3a6f66b8955d3ca55a4b76.tar.gz postgresql-68d9fbeb5511d846ce3a6f66b8955d3ca55a4b76.zip |
Implement the IS DISTINCT FROM operator per SQL99.
Reused the Expr node to hold DISTINCT which strongly resembles
the existing OP info. Define DISTINCT_EXPR which strongly resembles
the existing OPER_EXPR opType, but with handling for NULLs required
by SQL99.
We have explicit support for single-element DISTINCT comparisons
all the way through to the executor. But, multi-element DISTINCTs
are handled by expanding into a comparison tree in gram.y as is done for
other row comparisons. Per discussions, it might be desirable to move
this into one or more purpose-built nodes to be handled in the backend.
Define the optional ROW keyword and token per SQL99.
This allows single-element row constructs, which were formerly disallowed
due to shift/reduce conflicts with parenthesized a_expr clauses.
Define the SQL99 TREAT() function. Currently, use as a synonym for CAST().
Diffstat (limited to 'src/backend/nodes/outfuncs.c')
-rw-r--r-- | src/backend/nodes/outfuncs.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c index d11cedf3e5f..2b292635186 100644 --- a/src/backend/nodes/outfuncs.c +++ b/src/backend/nodes/outfuncs.c @@ -5,7 +5,7 @@ * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Header: /cvsroot/pgsql/src/backend/nodes/outfuncs.c,v 1.160 2002/06/20 20:29:29 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/nodes/outfuncs.c,v 1.161 2002/07/04 15:23:53 thomas Exp $ * * NOTES * Every (plan) node in POSTGRES has an associated "out" routine which @@ -719,6 +719,9 @@ _outExpr(StringInfo str, Expr *node) case OP_EXPR: opstr = "op"; break; + case DISTINCT_EXPR: + opstr = "distinct"; + break; case FUNC_EXPR: opstr = "func"; break; |