executor: fix unordered trace events in row format

[lucklove]

The trace statement can print out a trace tree, however, in row
format, the tree is unordered, where earlier events may be placed
behind.

Signed-off-by: lucklove [email protected]

What problem does this PR solve?

The trace statement may result unordered events tree, for example:

 MySQL  localhost:4000  SQL > trace format='row' select * from mysql.user limit 1;
+------------------------------------------+-----------------+-----------+
| operation                                | startTS         | duration  |
+------------------------------------------+-----------------+-----------+
| trace                                    | 16:22:29.456361 | 763.741µs |
|   ├─*executor.LimitExec.Next             | 16:22:29.456875 | 226.354µs |
|   │ └─*executor.TableReaderExecutor.Next | 16:22:29.456877 | 209.508µs |
|   ├─*executor.LimitExec.Next             | 16:22:29.457109 | 904ns     |
|   └─session.Execute                      | 16:22:29.456371 | 487.914µs |
|     ├─executor.Compile                   | 16:22:29.456448 | 265.957µs |
|     │ └─session.getTxnFuture             | 16:22:29.456455 | 1.173µs   |
|     ├─session.runStmt                    | 16:22:29.456725 | 101.817µs |
|     │ ├─TableReaderExecutor.Open         | 16:22:29.456750 | 37.667µs  |
|     │ │ └─distsql.Select                 | 16:22:29.456765 | 15.333µs  |
|     │ └─session.CommitTxn                | 16:22:29.456813 | 10.098µs  |
|     │   └─session.doCommitWitRetry       | 16:22:29.456815 | 1.873µs   |
|     └─session.ParseSQL                   | 16:22:29.456377 | 12.654µs  |
+------------------------------------------+-----------------+-----------+

session.ParseSQL is behind session.Compile, it's not correct.

What is changed and how it works?

Sort sub events before appending them into chunk.

Check List

Tests

• Unit test
• Manual test

trace select * from mysql.user limit 1;

Code changes

Side effects

Related changes

• Need to cherry-pick to the release branch

Release note

• fix unordered trace events in row format.

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

Merging #12314 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master    #12314   +/-   ##
=========================================
  Coverage   81.082%   81.082%           
=========================================
  Files          454       454           
  Lines        99128     99128           
=========================================
  Hits         80375     80375           
  Misses       12953     12953           
  Partials      5800      5800

[XuHuaiyu]

PTAL @tiancaiamao

[tiancaiamao]

LGTM

[tiancaiamao]

Once upon a time, the result is sorted, until I remove it by mistake. @lucklove
https://github.com/pingcap/tidb/pull/11633/files#diff-249234629b44bb39716865035fc89d8eL94

[XuHuaiyu]

LGTM

[zz-jason]

LGTM

[sre-bot]

Your auto merge job has been accepted, waiting for 12199, 12292

[sre-bot]

/run-all-tests

[sre-bot]

cherry pick to release-3.0 failed

[zz-jason]

@lucklove the bot failed to cherry pick this PR to release 3.0 and 3.1, could you manually in your spare time?

[lucklove]

@zz-jason OK, I'll do it

[sre-bot]

cherry pick to release-3.1 failed