lightning: replace information_schema query when importing table schema with separate show create table

[D3Hunter]

What problem does this PR solve?

Issue Number: ref #58141

Problem Summary:

What changed and how does it work?

info schema V2 only store one copy of schema object in memory, so read/write need to lock, if we read too much and takes too long, it affects write, i.e. schema reloading during DDL execution, we can mitigate this by using finer-grained lock, but we cannot avoid it completely with current strategy. so in lightning, we remove related queries, and avoid create table twice by IF NOT EXIST, and check table existence on error by SHOW CREATE TABLE, to make schema import part faster

we also found that the query to information_schema.tables is getting slower over time, and cause lightning dispatch jobs slower, we can fix it too by replace the query.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)

import 100K DB and total 200K tables, time reduced from 55m27 -> 19m20

before

after

• 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

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[codecov]

Codecov Report

Attention: Patch coverage is 85.10638% with 7 lines in your changes missing coverage. Please review.

Project coverage is 73.7541%. Comparing base (42d4fae) to head (ff0795f).
Report is 20 commits behind head on master.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #58636        +/-   ##
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+ Coverage   73.1093%   73.7541%   +0.6447%     
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  Files          1676       1706        +30     
  Lines        463354     472131      +8777     
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+ Hits         338755     348216      +9461     
+ Misses       103788     102378      -1410     
- Partials      20811      21537       +726     

Flag	Coverage Δ
integration	45.6783% <65.9574%> (?)
unit	72.2921% <85.1063%> (-0.0141%)	⬇️

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Components	Coverage Δ
dumpling	52.6910% <ø> (ø)
parser	∅ <ø> (∅)
br	45.8023% <ø> (ø)

Copilot reviewed 2 out of 7 changed files in this pull request and generated no comments.

Files not reviewed (5)

• lightning/tests/lightning_character_sets/run.sh: Language not supported
• lightning/tests/lightning_no_schema/data/noschema.invalid-schema.sql: Language not supported
• lightning/tests/lightning_no_schema/data/noschema.invalid.sql: Language not supported
• lightning/tests/lightning_no_schema/run.sh: Language not supported
• pkg/lightning/mydump/BUILD.bazel: Language not supported

Comments suppressed due to low confidence (1)

pkg/lightning/mydump/schema_import.go:259

• Ensure that the new error handling logic in 'runCreateTableJob' and 'runCommonJob' is covered by tests.

func (si *SchemaImporter) runCreateTableJob(ctx context.Context, p *parser.Parser, job *schemaJob) error {

[lance6716]

the package name errno is enough

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: lance6716

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-01-03 03:22:42.95985695 +0000 UTC m=+666298.315861491: ☑️ agreed by lance6716.