Fix: could not pull up equivalence class using projected target list

Ignore RelabelType nodes on top in pullUpExpr_mutator.

Author: yjhjstz

src/backend/cdb/cdbpullup.c

@@ -124,7 +124,9 @@ pullUpExpr_mutator(Node *node, void *context)
 			foreach(cell, ctx->targetlist)
 			{
 				tlistexpr = (Expr *) lfirst(cell);
-
+				/* Ignore RelabelType nodes on top */
+				while (tlistexpr && IsA(tlistexpr, RelabelType))
+					tlistexpr = ((RelabelType *) tlistexpr)->arg;
 				/*
 				 * We don't use equal(), because we want to ignore typmod.
 				 * A projection sometimes loses typmod, and that's OK.

src/test/regress/input/appendonly.source

@@ -879,3 +879,18 @@ insert into fix_ao_truncate_last_sequence select 1, 1 from generate_series(1, 5)
 select count(*) from fix_ao_truncate_last_sequence;
 abort;
 
+create table fix_issue_605
+(
+c1 varchar(8),
+c2 varchar(12) collate "C",
+c3 varchar(10),
+c4 varchar(30)
+)
+with (appendonly=true,compresstype=zstd,compresslevel=5)
+distributed by (c1,c3,c4)
+partition by range(c1)
+(partition p1990 start('19900101') inclusive,
+default partition other
+);
+
+select c3::varchar from fix_issue_605 where c1='20190830' order by c2;

src/test/regress/output/appendonly.source

@@ -1741,3 +1741,21 @@ select count(*) from fix_ao_truncate_last_sequence;
 (1 row)
 
 abort;
+create table fix_issue_605
+(
+c1 varchar(8),
+c2 varchar(12) collate "C",
+c3 varchar(10),
+c4 varchar(30)
+)
+with (appendonly=true,compresstype=zstd,compresslevel=5)
+distributed by (c1,c3,c4)
+partition by range(c1)
+(partition p1990 start('19900101') inclusive,
+default partition other
+);
+select c3::varchar from fix_issue_605 where c1='20190830' order by c2;
+ c3 
+----
+(0 rows)
+