From 211e157a51bf94dfcc143e78221951411f87e4b2 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 22 Feb 2013 07:30:21 -0500 Subject: [PATCH] Change postgres_fdw to show casts as casts, not underlying function calls. On reflection this method seems to be exposing an unreasonable amount of implementation detail. It wouldn't matter when talking to a remote server of the identical Postgres version, but it seems likely to make things worse not better if the remote is a different version with different casting infrastructure. Instead adopt ruleutils.c's policy of regurgitating the cast as it was originally specified; including not showing it at all, if it was implicit to start with. (We must do that because for some datatypes explicit and implicit casts have different semantics.) --- contrib/postgres_fdw/deparse.c | 42 +++++++++++++++---- .../postgres_fdw/expected/postgres_fdw.out | 24 +++++------ 2 files changed, 47 insertions(+), 19 deletions(-) diff --git a/contrib/postgres_fdw/deparse.c b/contrib/postgres_fdw/deparse.c index 1f4b2449be..93f2541cfc 100644 --- a/contrib/postgres_fdw/deparse.c +++ b/contrib/postgres_fdw/deparse.c @@ -855,10 +855,6 @@ deparseArrayRef(StringInfo buf, ArrayRef *node, PlannerInfo *root) /* * Deparse given node which represents a function call into buf. - * - * Here not only explicit function calls and explicit casts but also implicit - * casts are deparsed to avoid problems caused by different cast settings - * between local and remote. */ static void deparseFuncExpr(StringInfo buf, FuncExpr *node, PlannerInfo *root) @@ -870,6 +866,37 @@ deparseFuncExpr(StringInfo buf, FuncExpr *node, PlannerInfo *root) bool first; ListCell *arg; + /* + * If the function call came from an implicit coercion, then just show the + * first argument. + */ + if (node->funcformat == COERCE_IMPLICIT_CAST) + { + deparseExpr(buf, (Expr *) linitial(node->args), root); + return; + } + + /* + * If the function call came from a cast, then show the first argument + * plus an explicit cast operation. + */ + if (node->funcformat == COERCE_EXPLICIT_CAST) + { + Oid rettype = node->funcresulttype; + int32 coercedTypmod; + + /* Get the typmod if this is a length-coercion function */ + (void) exprIsLengthCoercion((Node *) node, &coercedTypmod); + + deparseExpr(buf, (Expr *) linitial(node->args), root); + appendStringInfo(buf, "::%s", + format_type_with_typemod(rettype, coercedTypmod)); + return; + } + + /* + * Normal function: display as proname(args). + */ proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(node->funcid)); if (!HeapTupleIsValid(proctup)) elog(ERROR, "cache lookup failed for function %u", node->funcid); @@ -1062,9 +1089,10 @@ static void deparseRelabelType(StringInfo buf, RelabelType *node, PlannerInfo *root) { deparseExpr(buf, node->arg, root); - appendStringInfo(buf, "::%s", - format_type_with_typemod(node->resulttype, - node->resulttypmod)); + if (node->relabelformat != COERCE_IMPLICIT_CAST) + appendStringInfo(buf, "::%s", + format_type_with_typemod(node->resulttype, + node->resulttypmod)); } /* diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out index 9a2c8e83cc..8af496a546 100644 --- a/contrib/postgres_fdw/expected/postgres_fdw.out +++ b/contrib/postgres_fdw/expected/postgres_fdw.out @@ -188,11 +188,11 @@ SELECT * FROM ft1 WHERE false; -- with WHERE clause EXPLAIN (VERBOSE, COSTS false) SELECT * FROM ft1 t1 WHERE t1.c1 = 101 AND t1.c6 = '1' AND t1.c7 >= '1'; - QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------- + QUERY PLAN +------------------------------------------------------------------------------------------------------------------------------------------------ Foreign Scan on public.ft1 t1 Output: c1, c2, c3, c4, c5, c6, c7, c8 - Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE ((c7 >= '1'::bpchar)) AND (("C 1" = 101)) AND ((c6::text = '1'::text)) + Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE ((c7 >= '1'::bpchar)) AND (("C 1" = 101)) AND ((c6 = '1'::text)) (3 rows) SELECT * FROM ft1 t1 WHERE t1.c1 = 101 AND t1.c6 = '1' AND t1.c7 >= '1'; @@ -353,11 +353,11 @@ EXPLAIN (VERBOSE, COSTS false) SELECT * FROM ft1 t1 WHERE c1 IS NOT NULL; -- (3 rows) EXPLAIN (VERBOSE, COSTS false) SELECT * FROM ft1 t1 WHERE round(abs(c1), 0) = 1; -- FuncExpr - QUERY PLAN --------------------------------------------------------------------------------------------------------------------------------- + QUERY PLAN +--------------------------------------------------------------------------------------------------------------------- Foreign Scan on public.ft1 t1 Output: c1, c2, c3, c4, c5, c6, c7, c8 - Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE ((round("numeric"(abs("C 1")), 0) = 1::numeric)) + Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE ((round(abs("C 1"), 0) = 1::numeric)) (3 rows) EXPLAIN (VERBOSE, COSTS false) SELECT * FROM ft1 t1 WHERE c1 = -c1; -- OpExpr(l) @@ -369,11 +369,11 @@ EXPLAIN (VERBOSE, COSTS false) SELECT * FROM ft1 t1 WHERE c1 = -c1; -- (3 rows) EXPLAIN (VERBOSE, COSTS false) SELECT * FROM ft1 t1 WHERE 1 = c1!; -- OpExpr(r) - QUERY PLAN ----------------------------------------------------------------------------------------------------------------- + QUERY PLAN +---------------------------------------------------------------------------------------------------------- Foreign Scan on public.ft1 t1 Output: c1, c2, c3, c4, c5, c6, c7, c8 - Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE ((1::numeric = (int8("C 1") !))) + Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE ((1::numeric = ("C 1" !))) (3 rows) EXPLAIN (VERBOSE, COSTS false) SELECT * FROM ft1 t1 WHERE (c1 IS NOT NULL) IS DISTINCT FROM (c1 IS NOT NULL); -- DistinctExpr @@ -401,11 +401,11 @@ EXPLAIN (VERBOSE, COSTS false) SELECT * FROM ft1 t1 WHERE c1 = (ARRAY[c1,c2,3])[ (3 rows) EXPLAIN (VERBOSE, COSTS false) SELECT * FROM ft1 t1 WHERE c6 = E'foo''s\\bar'; -- check special chars - QUERY PLAN -------------------------------------------------------------------------------------------------------------------- + QUERY PLAN +------------------------------------------------------------------------------------------------------------- Foreign Scan on public.ft1 t1 Output: c1, c2, c3, c4, c5, c6, c7, c8 - Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE ((c6::text = E'foo''s\\bar'::text)) + Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE ((c6 = E'foo''s\\bar'::text)) (3 rows) EXPLAIN (VERBOSE, COSTS false) SELECT * FROM ft1 t1 WHERE c8 = 'foo'; -- can't be sent to remote -- 2.40.0