[Fix](Nereids) Fix problem of infer predicates not completely #22145
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Contributor
Author
|
run buildall |
Contributor
|
(From new machine)TeamCity pipeline, clickbench performance test result: |
morrySnow
approved these changes
Jul 24, 2023
github-actions
bot
added
the
approved
Contributor
|
PR approved by at least one committer and no changes requested. |
Contributor
|
PR approved by anyone and no changes requested. |
englefly
approved these changes
Jul 25, 2023
xiaokang
pushed a commit
that referenced
this pull request
Jul 25, 2023
Problem:
When inferring predicate in nereids, new inferred predicates can not be the source of next round. For example:
create table tt1(c1 int, c2 int) distributed by hash(c1) properties('replication_num'='1');
create table tt2(c1 int, c2 int) distributed by hash(c1) properties('replication_num'='1');
create table tt3(c1 int, c2 int) distributed by hash(c1) properties('replication_num'='1');
explain select * from tt1 left join tt2 on tt1.c1 = tt2.c1 left join tt3 on tt2.c1 = tt3.c1 where tt1.c1 = 123;
we expect to get t33.c1 = 123, but we can just get t22.c1 = 123. Because when infer tt1.c1 = 123 and tt2.c1 = tt3.c1, we can
not get any relationship of these two predicates.
Solution:
We need to cache middle results of source predicates like t22.c1 = 123 in example.
morrySnow
added a commit
to morrySnow/incubator-doris
that referenced
this pull request
Aug 24, 2023
We use two facilities to do predicate infer: PredicatePropagation and PullUpPredicates. In the prvious implementation, we use a set to save the intermediate result of PredicatePropagation. The purpose is infer new predicate though two equal relation. However, it is the wrong way. Because it could infer wrong predicate through outer join. For example ```sql select a.c1 from a left join b on a.c2 = b.c2 and a.c1 = '1' left join c on a.c2 = c.c2 and a.c1 = '2' inner join d on a.c3=d.c3 ``` the predicates `a.c1 = '1'` and `a.c1 = '2'` should not be inferred as filter to relation `a`. This PR: 1. revert the change from PR apache#22145, commit 3c58e9b 2. Remove the unreasonable restrict in PullupPredicate. 3. Use new Filter node rather than new otherCondition on join node to save infer predicates
morrySnow
added a commit
that referenced
this pull request
Aug 25, 2023
We use two facilities to do predicate infer: PredicatePropagation and PullUpPredicates. In the prvious implementation, we use a set to save the intermediate result of PredicatePropagation. The purpose is infer new predicate though two equal relation. However, it is the wrong way. Because it could infer wrong predicate through outer join. For example ```sql select a.c1 from a left join b on a.c2 = b.c2 and a.c1 = '1' left join c on a.c2 = c.c2 and a.c1 = '2' inner join d on a.c3=d.c3 ``` the predicates `a.c1 = '1'` and `a.c1 = '2'` should not be inferred as filter to relation `a`. This PR: 1. revert the change from PR #22145, commit 3c58e9b 2. Remove the unreasonable restrict in PullupPredicate. 3. Use new Filter node rather than new otherCondition on join node to save infer predicates
xiaokang
pushed a commit
that referenced
this pull request
Aug 25, 2023
We use two facilities to do predicate infer: PredicatePropagation and PullUpPredicates. In the prvious implementation, we use a set to save the intermediate result of PredicatePropagation. The purpose is infer new predicate though two equal relation. However, it is the wrong way. Because it could infer wrong predicate through outer join. For example ```sql select a.c1 from a left join b on a.c2 = b.c2 and a.c1 = '1' left join c on a.c2 = c.c2 and a.c1 = '2' inner join d on a.c3=d.c3 ``` the predicates `a.c1 = '1'` and `a.c1 = '2'` should not be inferred as filter to relation `a`. This PR: 1. revert the change from PR #22145, commit 3c58e9b 2. Remove the unreasonable restrict in PullupPredicate. 3. Use new Filter node rather than new otherCondition on join node to save infer predicates
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
5 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Proposed changes
Problem:
When inferring predicate in nereids, new inferred predicates can not be the source of next round. For example:
create table tt1(c1 int, c2 int) distributed by hash(c1) properties('replication_num'='1');
create table tt2(c1 int, c2 int) distributed by hash(c1) properties('replication_num'='1');
create table tt3(c1 int, c2 int) distributed by hash(c1) properties('replication_num'='1');
explain select * from tt1 left join tt2 on tt1.c1 = tt2.c1 left join tt3 on tt2.c1 = tt3.c1 where tt1.c1 = 123;
we expect to get t33.c1 = 123, but we can just get t22.c1 = 123. Because when infer tt1.c1 = 123 and tt2.c1 = tt3.c1, we can
not get any relationship of these two predicates.
Solution:
We need to cache middle results of source predicates like t22.c1 = 123 in example.
Further comments
If this is a relatively large or complex change, kick off the discussion at dev@doris.apache.org by explaining why you chose the solution you did and what alternatives you considered, etc...