importinto: cleanup sorted files, writer memory quota, and test

[D3Hunter]

What problem does this PR solve?

Issue Number: ref #46704

Problem Summary:

• cleanup sorted files when task done
• calculate writer memory quota based on index count
• test

What is changed and how it works?

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

[tiprow]

Hi @D3Hunter. Thanks for your PR.

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[codecov]

Codecov Report

Merging #47092 (8b3b6ce) into master (4450ae4) will decrease coverage by 0.2705%.
Report is 13 commits behind head on master.
The diff coverage is 71.7557%.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #47092        +/-   ##
================================================
- Coverage   72.9633%   72.6929%   -0.2705%     
================================================
  Files          1337       1359        +22     
  Lines        399007     405580      +6573     
================================================
+ Hits         291129     294828      +3699     
- Misses        89075      92016      +2941     
+ Partials      18803      18736        -67     

Flag	Coverage Δ
integration	30.4429% <0.0000%> (?)
unit	73.0392% <71.7557%> (+0.0758%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
dumpling	53.9913% <ø> (ø)
parser	84.9620% <ø> (-0.0108%)	⬇️
br	48.7485% <100.0000%> (-4.1912%)	⬇️

[D3Hunter]

/ok-to-test

[Benjamin2037]

LGTM

[D3Hunter]

/retest

[okJiang]

rest lgtm

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

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

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• OWNERS [okJiang]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-09-19 12:28:57.371211852 +0000 UTC m=+606903.338799902: ☑️ agreed by Benjamin2037.
• 2023-09-20 08:47:13.446414765 +0000 UTC m=+679999.414002800: ☑️ agreed by okJiang.