NotificationsYou must be signed in to change notification settings
Fork6
Star31

Commitbf31535

committed

Don't Memoize lateral joins with volatile join conditions

The use of Memoize was already disabled in normal joins when the joinconditions had volatile functions per the code inmatch_opclause_to_indexcol(). Ordinarily, the parameterization for theinner side of a nested loop will be an Index Scan or at least eventuallylead to an index scan (perhaps nested several joins deep). However, forlateral joins, that's not the case and seq scans can be parameterizedtoo, so we can't rely on match_opclause_to_indexcol().Here we explicitly check the parameterization for volatile functions anddon't consider the generation of a Memoize path when such functionsare present.Author: Richard GuoDiscussion:https://postgr.es/m/CAMbWs49nHFnHbpepLsv_yF3qkpCS4BdB-v8HoJVv8_=Oat0u_w@mail.gmail.comBackpatch-through: 14, where Memoize was introduced

1 parent7c9f0c0 commitbf31535Copy full SHA for bf31535

File tree

1 file changed

+17

-0

lines changed

src/backend/optimizer/path
- joinpath.c

1 file changed

+17

-0

lines changed

`‎src/backend/optimizer/path/joinpath.c`

Lines changed: 17 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -595,6 +595,23 @@ get_memoize_path(PlannerInfo root, RelOptInfo innerrel,`
`595`	`595`	`returnNULL;`
`596`	`596`	`}`
`597`	`597`
	`598`	`+/*`
	`599`	`+ * Also check the parameterized path restrictinfos for volatile functions.`
	`600`	`+ * Indexed functions must be immutable so shouldn't have any volatile`
	`601`	`+ * functions, however, with a lateral join the inner scan may not be an`
	`602`	`+ * index scan.`
	`603`	`+ */`
	`604`	`+if (inner_path->param_info!=NULL)`
	`605`	`+{`
	`606`	`+foreach(lc,inner_path->param_info->ppi_clauses)`
	`607`	`+{`
	`608`	`+RestrictInforinfo= (RestrictInfo)lfirst(lc);`
	`609`	`+`
	`610`	`+if (contain_volatile_functions((Node*)rinfo))`
	`611`	`+returnNULL;`
	`612`	`+}`
	`613`	`+}`
	`614`	`+`
`598`	`615`	`/*`
`599`	`616`	`* When considering a partitionwise join, we have clauses that reference`
`600`	`617`	`* the outerrel's top parent not outerrel itself.`

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!

Commitbf31535

File tree

1 file changed

1 file changed

`‎src/backend/optimizer/path/joinpath.c`

0 commit comments