Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Optimise hash joins #14644

Merged
merged 18 commits into from
Dec 12, 2023
Merged

Optimise hash joins #14644

merged 18 commits into from
Dec 12, 2023

Conversation

systay
Copy link
Collaborator

@systay systay commented Nov 30, 2023 •
edited
Loading

Description

We recently added support for more queries by using hash joins when a nested loop join is not possible to use.

At the moment these queries would work, but only by moving the data to the vtgate proxy and there doing the necessary operations on the data. This makes a lot of queries intractable - they work only on toy datasets and would time out on real data sizes.

This PR adds logic to push most of the work down to mysql.

Related Issue(s)

PR that introduced hash joins: #14448

Checklist

  • "Backport to:" labels have been added if this change should be back-ported
  • Tests were added or are not required
  • Did the new or modified tests pass consistently locally and on the CI
  • Documentation was added or is not required

@vitess-bot vitess-bot
Copy link
Contributor

vitess-bot bot commented Nov 30, 2023

Review Checklist

Hello reviewers! 👋 Please follow this checklist when reviewing this Pull Request.

General

  • Ensure that the Pull Request has a descriptive title.
  • Ensure there is a link to an issue (except for internal cleanup and flaky test fixes), new features should have an RFC that documents use cases and test cases.

Tests

  • Bug fixes should have at least one unit or end-to-end test, enhancement and new features should have a sufficient number of tests.

Documentation

  • Apply the release notes (needs details) label if users need to know about this change.
  • New features should be documented.
  • There should be some code comments as to why things are implemented the way they are.
  • There should be a comment at the top of each new or modified test to explain what the test does.

New flags

  • Is this flag really necessary?
  • Flag names must be clear and intuitive, use dashes (-), and have a clear help text.

If a workflow is added or modified:

  • Each item in Jobs should be named in order to mark it as required.
  • If the workflow needs to be marked as required, the maintainer team must be notified.

Backward compatibility

  • Protobuf changes should be wire-compatible.
  • Changes to _vt tables and RPCs need to be backward compatible.
  • RPC changes should be compatible with vitess-operator
  • If a flag is removed, then it should also be removed from vitess-operator and arewefastyet, if used there.
  • vtctl command output order should be stable and awk-able.

@vitess-bot vitess-bot bot added NeedsDescriptionUpdate The description is not clear or comprehensive enough, and needs work NeedsIssue A linked issue is missing for this Pull Request NeedsWebsiteDocsUpdate What it says labels Nov 30, 2023
@github-actions github-actions bot added this to the v19.0.0 milestone Nov 30, 2023
@systay systay added Type: Enhancement Logical improvement (somewhere between a bug and feature) Component: Query Serving and removed NeedsDescriptionUpdate The description is not clear or comprehensive enough, and needs work NeedsWebsiteDocsUpdate What it says NeedsIssue A linked issue is missing for this Pull Request labels Nov 30, 2023
@systay systay force-pushed the hash-join-pushing branch from a40c08f to ef546e7 Compare December 6, 2023 06:56
@systay systay force-pushed the hash-join-pushing branch from 15bcdba to 5ba9cd4 Compare December 7, 2023 13:20
@systay systay force-pushed the hash-join-pushing branch from 5ba9cd4 to 9d37cc8 Compare December 7, 2023 14:05
@systay systay force-pushed the hash-join-pushing branch from fcd773c to a41459a Compare December 8, 2023 08:44
@systay systay marked this pull request as ready for review December 8, 2023 08:45
GuptaManan100
GuptaManan100 reviewed Dec 8, 2023
View reviewed changes
go/test/endtoend/vtgate/queries/aggregation/aggregation_test.go
"t2.shardKey",
}

// quickly construct a big number of left join aggregation queries that have to be executed using the hash join
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

nice

go/vt/vtgate/planbuilder/operators/hash_join.go Outdated Show resolved Hide resolved
go/vt/vtgate/planbuilder/operators/hash_join.go Outdated
inOffset = op.AddColumn(ctx, false, false, aeWrap(expr))
}

// we turn the
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Looks like an incomplete comment

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

so, the idea was that we

go/vt/vtgate/planbuilder/testdata/aggr_cases.json Outdated Show resolved Hide resolved
systay added 3 commits December 8, 2023 12:40
@systay
refactor: rename method and clean up comment
ac88590 
Signed-off-by: Andres Taylor <[email protected]>
@systay
Merge remote-tracking branch 'upstream/main' into hash-join-pushing
f0f8ca0 
Signed-off-by: Andres Taylor <[email protected]>
@systay
test: fix test expectation that got copied wrongly
ca8dc6e 
also changing the reading of the json test files so
that our plan tests fail if they don't
follow the expected format

Signed-off-by: Andres Taylor <[email protected]>
@systay systay force-pushed the hash-join-pushing branch from c345522 to ca8dc6e Compare December 9, 2023 15:14
@systay systay merged commit 18181f6 into vitessio:main Dec 12, 2023
116 checks passed
@systay systay deleted the hash-join-pushing branch December 12, 2023 07:57
ejortegau pushed a commit to slackhq/vitess that referenced this pull request Dec 13, 2023
@systay @GuptaManan100 @ejortegau
Optimise hash joins (vitessio#14644)
75e06df 
Co-authored-by: Manan Gupta <[email protected]>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Reviewers

@GuptaManan100 GuptaManan100 GuptaManan100 approved these changes

@frouioui frouioui frouioui approved these changes

@harshit-gangal harshit-gangal Awaiting requested review from harshit-gangal harshit-gangal is a code owner

@arthurschreiber arthurschreiber Awaiting requested review from arthurschreiber arthurschreiber is a code owner

Assignees
No one assigned
Labels
Component: Query Serving Type: Enhancement Logical improvement (somewhere between a bug and feature)
Projects
None yet
Milestone
v19.0.0
Development

Successfully merging this pull request may close these issues.
3 participants
@systay @frouioui @GuptaManan100