executor: make projection executor unparallel for insert/update/delete (#30290)

[ti-srebot]

cherry-pick #30290 to release-5.1
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# In tidb repo:
git pr https://github.com/pingcap/tidb/pull/30386

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git push git@github.com:ti-srebot/tidb.git pr/30386:release-5.1-4fbbd5a77df2

---

What problem does this PR solve?

Issue Number: close #26832

Problem Summary:

The memdb is not thread-safe, and that's the root cause of issue 26832

What is changed and how it works?

In insert/update/delete statement, do not use the parallel projection, choose the unparallel one intead.

This can avoid the concurrent visit of the memdb in issue 26832.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

I try to add some unit test code like this and run it with -race flag, but can't reproduce.

+func (s *testSuite8) TestIssues26832DataRace(c *C) {
+       tk := testkit.NewTestKit(c, s.store)
+       tk.MustExec("use test")
+       tk.MustExec("drop table if exists t")
+       tk.MustExec("create table t (a int unique)")
+       tk.MustExec(`CREATE TABLE IF NOT EXISTS order_line (
+               ol_o_id INT NOT NULL,
+               ol_d_id INT NOT NULL,
+               ol_w_id INT NOT NULL,
+               ol_i_id INT NOT NULL,
+               ol_delivery_d INT,
+               PRIMARY KEY(ol_w_id, ol_d_id, ol_o_id)) partition by hash(ol_w_id) partitions 10`)
+       for i:=0; i<1000; i++ {
+               tk.MustExec("insert into order_line value (?, ?, ?, ?, ?)", i, i, i, i, i)
+       }
+
+       for i:=0; i<1000; i++ {
+               v := rand.Intn(1000)
+               tk.MustExec(`UPDATE order_line SET ol_delivery_d = ol_delivery_d + 1 WHERE (ol_w_id, ol_d_id, ol_o_id) IN (
+       (?,?,?),(?,?,?),(?,?,?),(?,?,?),(?,?,?),(?,?,?),(?,?,?),(?,?,?),(?,?,?),(?,?,?))`,
+                       v,v,v,
+                       v,v,v,
+                       v,v,v,
+                       v,v,v,
+                       v,v,v,
+                       v,v,v,
+                       v,v,v,
+                       v,v,v,
+                       v,v,v,
+                       v,v,v)
+       }
+}

and then, I try the TPCC on my local machine, and with no luck ... it doesn't reproduce

tiup bench tpcc --warehouses 10 --parts 10 prepare -T 16 -D bench
tiup bench tpcc --warehouses 10 --parts 10 run -T 16 -D bench

This change is simple enough, so maybe we can merge it first and see whether it reproduce in the future.

Side effects

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

It should not impact the write performance in most cases, because the insert/update/delete is unparalleled
and be the bottleneck, the change of projection does't change this fact.

Documentation

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

Release note

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• bb7133
• cfzjywxk

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[ti-srebot]

/run-all-tests

[ti-srebot]

@tiancaiamao you're already a collaborator in bot's repo.

[bb7133]

LGTM

[bb7133]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 21ed81d

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