NotificationsYou must be signed in to change notification settings
Fork6
Star31

Commit4c49611

Richard Guo

committed

Remove code setting wrap_non_vars to true for UNION ALL subqueries

In pull_up_simple_subquery and pull_up_constant_function, there iscode that sets wrap_non_vars to true when dealing with an appendrelmember. The goal is to wrap subquery outputs that are not simple Varsin PlaceHolderVars, ensuring that what we pull up doesn't get mergedinto a surrounding expression during later processing, which couldcause it to fail to match the expression actually available from theappendrel.However, this is unnecessary. When pulling up an appendrel childsubquery, the only part of the upper query that could reference theappendrel child yet is the translated_vars list of the associatedAppendRelInfo that we just made for this child. Furthermore, we donot want to force use of PHVs in the AppendRelInfo, as there is noouter join between. In fact, perform_pullup_replace_vars always setswrap_non_vars to false before performing pullup_replace_vars on theAppendRelInfo.This patch simply removes the code that sets wrap_non_vars to true forUNION ALL subqueries.Author: Richard Guo <guofenglinux@gmail.com>Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>Discussion:https://postgr.es/m/CAMbWs4-VXDEi1v+hZYLxpOv0riJxHsCkCH1f46tLnhonEAyGCQ@mail.gmail.com

1 parentd3b2e5e commit4c49611Copy full SHA for 4c49611

File tree

1 file changed

-25

lines changed

src/backend/optimizer/prep
- prepjointree.c

1 file changed

-25

lines changed

`‎src/backend/optimizer/prep/prepjointree.c`

Lines changed: 8 additions & 25 deletions

Original file line number	Diff line number	Diff line change
`@@ -1440,24 +1440,14 @@ pull_up_simple_subquery(PlannerInfo root, Node jtnode, RangeTblEntry *rte,`
`1440`	`1440`	`rvcontext.rv_cache=palloc0((list_length(subquery->targetList)+1)*`
`1441`	`1441`	`sizeof(Node*));`
`1442`	`1442`
`1443`		`-/*`
`1444`		`- * If we are dealing with an appendrel member then anything that's not a`
`1445`		`- * simple Var has to be turned into a PlaceHolderVar. We force this to`
`1446`		`- * ensure that what we pull up doesn't get merged into a surrounding`
`1447`		`- * expression during later processing and then fail to match the`
`1448`		`- * expression actually available from the appendrel.`
`1449`		`- */`
`1450`		`-if (containing_appendrel!=NULL)`
`1451`		`-rvcontext.wrap_non_vars= true;`
`1452`		`-`
`1453`	`1443`	`/*`
`1454`	`1444`	`* If the parent query uses grouping sets, we need a PlaceHolderVar for`
`1455`		`- * anything that's not a simple Var.Again, thisensures that expressions`
`1456`		`- *retaintheir separate identity so that they will match grouping set`
`1457`		`- *columnswhen appropriate. (It'd be sufficient to wrap values used in`
`1458`		`- *groupingset columns, and do so only in non-aggregated portions of the`
`1459`		`- *tlist andhavingQual, but that would require a lot of infrastructure`
`1460`		`- *thatpullup_replace_vars hasn't currently got.)`
	`1445`	`+ * anything that's not a simple Var.Thisensures that expressions retain`
	`1446`	`+ * their separate identity so that they will match grouping set columns`
	`1447`	`+ * when appropriate. (It'd be sufficient to wrap values used in grouping`
	`1448`	`+ * set columns, and do so only in non-aggregated portions of the tlist and`
	`1449`	`+ * havingQual, but that would require a lot of infrastructure that`
	`1450`	`+ * pullup_replace_vars hasn't currently got.)`
`1461`	`1451`	`*/`
`1462`	`1452`	`if (parse->groupingSets)`
`1463`	`1453`	`rvcontext.wrap_non_vars= true;`
`@@ -2159,17 +2149,10 @@ pull_up_constant_function(PlannerInfo root, Node jtnode,`
`2159`	`2149`	`rvcontext.rv_cache=palloc0((list_length(rvcontext.targetlist)+1)*`
`2160`	`2150`	`sizeof(Node*));`
`2161`	`2151`
`2162`		`-/*`
`2163`		`- * If we are dealing with an appendrel member then anything that's not a`
`2164`		`- * simple Var has to be turned into a PlaceHolderVar. (See comments in`
`2165`		`- * pull_up_simple_subquery().)`
`2166`		`- */`
`2167`		`-if (containing_appendrel!=NULL)`
`2168`		`-rvcontext.wrap_non_vars= true;`
`2169`		`-`
`2170`	`2152`	`/*`
`2171`	`2153`	`* If the parent query uses grouping sets, we need a PlaceHolderVar for`
`2172`		`- * anything that's not a simple Var.`
	`2154`	`+ * anything that's not a simple Var. (See comments in`
	`2155`	`+ * pull_up_simple_subquery().)`
`2173`	`2156`	`*/`
`2174`	`2157`	`if (parse->groupingSets)`
`2175`	`2158`	`rvcontext.wrap_non_vars= true;`

0 commit comments

Comments

(0)

Movatterモバイル変換

Navigation Menu

Search code, repositories, users, issues, pull requests...

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Commit4c49611

File tree

1 file changed

1 file changed

`‎src/backend/optimizer/prep/prepjointree.c`

0 commit comments