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executor: change the evaluation order of columns in Update and Insert statements (#57123) #58494

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This is an automated cherry-pick of #57123

What problem does this PR solve?

Issue Number: ref #56829

Problem Summary:

In the previous logic, when we use UPDATE or INSERT ON DUPLICATE, the new row will be generated in the following order:

  • Fill all the explicitly set columns.
  • Evaluate all auto-generated columns. For UPDATE and INSERT, they are evaluated in composeGeneratedColumns and doDupRowUpdate respectively.
  • Update on-update-now columns if necessary.

However, auto-generated columns may rely on the on-update-now columns to generate value. For example in #56829 (comment)

CREATE TABLE cache (
  cache_key varchar(512) NOT NULL,
  updated_at datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  expired_at datetime GENERATED ALWAYS AS (if(expires > 0, date_add(updated_at, interval expires second), date_add(updated_at, interval 99 year))) VIRTUAL,
  expires int(11),
  PRIMARY KEY (cache_key) /*T![clustered_index] CLUSTERED */,
  KEY idx_c_on_expired_at (expired_at)
);

expired_at is generated based on the latest timestamp value from updated_at. So we will get wrong expired_at value. Even worse, expired_at is the part of the index idx_c_on_expired_at. So querying data expired_at using index scan and full table scan will get different result, since in full table scan, expired_at is calculated in real-time.

This also explains #56829 (comment) why changing VIRTUAL to STORED will not yield such error, although this value itself is incorrect.

What changed and how does it work?

To address this problem, this PR refactor the logic of INSERT ON DUPLICATE and UPDATE. More specifically:

  • Move the evalation of auto-generated columns in updateRecord.
  • ForeignKey Check is also moved into updateRecord.
  • Extract errorHandler function for UPDATE and INSERT to handle error/warning in updateRecord.

Check List

Tests

  • Unit test
  • Integration test
  • Manual test (add detailed scripts or steps below)
  • No need to test
    • I checked and no code files have been changed.

Side effects

  • Performance regression: Consumes more CPU
  • Performance regression: Consumes more Memory
  • Breaking backward compatibility

Documentation

  • Affects user behaviors
  • Contains syntax changes
  • Contains variable changes
  • Contains experimental features
  • Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

@ti-chi-bot ti-chi-bot added ok-to-test Indicates a PR is ready to be tested. release-note-none Denotes a PR that doesn't merit a release note. size/XXL Denotes a PR that changes 1000+ lines, ignoring generated files. type/cherry-pick-for-release-7.5 This PR is cherry-picked to release-7.5 from a source PR. labels Dec 24, 2024
@ti-chi-bot ti-chi-bot bot added size/XL Denotes a PR that changes 500-999 lines, ignoring generated files. and removed size/XXL Denotes a PR that changes 1000+ lines, ignoring generated files. labels Dec 24, 2024
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codecov bot commented Dec 24, 2024

Codecov Report

Attention: Patch coverage is 79.53488% with 44 lines in your changes missing coverage. Please review.

Please upload report for BASE (release-7.5@f3038bc). Learn more about missing BASE report.

Additional details and impacted files
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##             release-7.5     #58494   +/-   ##
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Flag Coverage Δ
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Flags with carried forward coverage won't be shown. Click here to find out more.

Components Coverage Δ
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parser ∅ <0.0000%> (?)
br 53.8735% <0.0000%> (?)

@Benjamin2037 Benjamin2037 added needs-cherry-pick-release-8.1 Should cherry pick this PR to release-8.1 branch. needs-cherry-pick-release-8.5 Should cherry pick this PR to release-8.5 branch. and removed needs-cherry-pick-release-8.1 Should cherry pick this PR to release-8.1 branch. needs-cherry-pick-release-8.5 Should cherry pick this PR to release-8.5 branch. labels Jan 13, 2025
@ti-chi-bot ti-chi-bot bot added cherry-pick-approved Cherry pick PR approved by release team. and removed do-not-merge/cherry-pick-not-approved labels Feb 10, 2025
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LGTM

@ti-chi-bot ti-chi-bot bot added approved needs-1-more-lgtm Indicates a PR needs 1 more LGTM. labels Feb 27, 2025
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ti-chi-bot bot commented Feb 27, 2025

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Benjamin2037, fzzf678

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@ti-chi-bot ti-chi-bot bot added lgtm and removed needs-1-more-lgtm Indicates a PR needs 1 more LGTM. labels Feb 27, 2025
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ti-chi-bot bot commented Feb 27, 2025

[LGTM Timeline notifier]

Timeline:

  • 2025-02-27 07:46:08.748460711 +0000 UTC m=+514716.701618977: ☑️ agreed by Benjamin2037.
  • 2025-02-27 07:59:08.598217747 +0000 UTC m=+515496.551376008: ☑️ agreed by fzzf678.

@ti-chi-bot ti-chi-bot bot merged commit e34e953 into pingcap:release-7.5 Feb 27, 2025
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4 participants