IT unstable case TestPreparePlanCacheNotForCacheTable

[aytrack]

Bug Report

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1. Minimal reproduce step (Required)

in ci https://ci.pingcap.net/blue/organizations/jenkins/tidb_ghpr_coverage/detail/tidb_ghpr_coverage/1422/pipeline

2021-12-01T09:44:33.665Z] FAIL: integration_test.go:6217: testIntegrationSerialSuite.TestPreparePlanCacheNotForCacheTable
[2021-12-01T09:44:33.665Z] 
[2021-12-01T09:44:33.665Z] integration_test.go:6235:
[2021-12-01T09:44:33.665Z]     // already read cache after reading first time
[2021-12-01T09:44:33.665Z]     tk.MustQuery("explain format = 'brief' select * from t where a = 1").Check(testkit.Rows(
[2021-12-01T09:44:33.666Z]         "Projection 10.00 root  test.t.a",
[2021-12-01T09:44:33.666Z]         "└─UnionScan 10.00 root  eq(test.t.a, 1)",
[2021-12-01T09:44:33.666Z]         "  └─TableReader 10.00 root  data:Selection",
[2021-12-01T09:44:33.666Z]         "    └─Selection 10.00 cop[tikv]  eq(test.t.a, 1)",
[2021-12-01T09:44:33.666Z]         "      └─TableFullScan 10000.00 cop[tikv] table:t keep order:false, stats:pseudo"))
[2021-12-01T09:44:33.666Z] /home/jenkins/agent/workspace/tidb_ghpr_coverage/go/src/github.com/pingcap/tidb/util/testkit/testkit.go:67:
[2021-12-01T09:44:33.666Z]     res.c.Assert(resBuff.String(), check.Equals, needBuff.String(), res.comment)
[2021-12-01T09:44:33.666Z] ... obtained string = "" +
[2021-12-01T09:44:33.666Z] ...     "[TableReader 10.00 root  data:Selection]\n" +
[2021-12-01T09:44:33.666Z] ...     "[└─Selection 10.00 cop[tikv]  eq(test.t.a, 1)]\n" +
[2021-12-01T09:44:33.666Z] ...     "[  └─TableFullScan 10000.00 cop[tikv] table:t keep order:false, stats:pseudo]\n"
[2021-12-01T09:44:33.666Z] ... expected string = "" +
[2021-12-01T09:44:33.666Z] ...     "[Projection 10.00 root  test.t.a]\n" +
[2021-12-01T09:44:33.666Z] ...     "[└─UnionScan 10.00 root  eq(test.t.a, 1)]\n" +
[2021-12-01T09:44:33.666Z] ...     "[  └─TableReader 10.00 root  data:Selection]\n" +
[2021-12-01T09:44:33.666Z] ...     "[    └─Selection 10.00 cop[tikv]  eq(test.t.a, 1)]\n" +
[2021-12-01T09:44:33.666Z] ...     "[      └─TableFullScan 10000.00 cop[tikv] table:t keep order:false, stats:pseudo]\n"
[2021-12-01T09:44:33.666Z] ... sql:explain format = 'brief' select * from t where a = 1, args:[]
[2021-12-01T09:44:33.666Z] 

2. What did you expect to see? (Required)

3. What did you see instead (Required)

4. What is your TiDB version? (Required)

[Reminiscent]

@sylzd @tiancaiamao PTAL

[yudongusa]

@Reminiscent @tiancaiamao Was the root cause identified?

[tiancaiamao]

I'm not sure, it's still a developing feature, after #30206 I will take a look.
Maybe it will disappear by itself...

If this fails a lot in our CI I'll give it a higher priority.

@yudongusa

[yudongusa]

I'm not sure, it's still a developing feature, after #30206 I will take a look. Maybe it will disappear by itself...

If this fails a lot in our CI I'll give it a higher priority.

@yudongusa

Ok, we can check back with the new feature. I removed bug label first as discussed with QA team since it will be handled by features.

[tiancaiamao]

Close, this is an issue during developing, it never reproduce recently.