planner: add unit test for tidb_opt_prefer_range_scan variable

[xiaodong-ji]

What problem does this PR solve?

Problem Summary:

What is changed and how it works?

What's Changed: add unit test for tidb_opt_prefer_range_scan variable.

Related changes

• PR: planner: support variable to prefer index scan #18996

Check List

Tests

• Unit test

Release note

• add unit test for tidb_opt_prefer_range_scan variable

[xiaodong-ji]

/run-check_dev_2

[xiaodong-ji]

/run-check_dev_2

[ti-srebot]

@winoros, @qw4990, @hanfei1991, PTAL.

[ti-srebot]

@winoros, @qw4990, @hanfei1991, PTAL.

[ti-srebot]

@winoros, @qw4990, @hanfei1991, PTAL.

[winoros]

lgtm

[qw4990]

LGTM

[qw4990]

/merge

[ti-srebot]

Your auto merge job has been accepted, waiting for:

• 20744

[ti-srebot]

/run-all-tests

[lzmhhh123]

The test is often failed:

[2020-11-23T09:45:42.107Z] physical_plan_test.go:1731:

[2020-11-23T09:45:42.107Z]     tk.MustQuery("explain " + ts).Check(testkit.Rows(output[i].Plan...))

[2020-11-23T09:45:42.107Z] /home/jenkins/agent/workspace/tidb_ghpr_check_2/go/src/github.com/pingcap/tidb/util/testkit/testkit.go:63:

[2020-11-23T09:45:42.107Z]     res.c.Assert(resBuff.String(), check.Equals, needBuff.String(), res.comment)

[2020-11-23T09:45:42.107Z] ... obtained string = "" +

[2020-11-23T09:45:42.107Z] ...     "[IndexLookUp_7 1441.12 root  ]\n" +

[2020-11-23T09:45:42.107Z] ...     "[├─IndexRangeScan_5(Build) 1441.12 cop[tikv] table:test, index:idx_age(age) range:[5,5], keep order:false]\n" +

[2020-11-23T09:45:42.108Z] ...     "[└─TableRowIDScan_6(Probe) 1441.12 cop[tikv] table:test keep order:false]\n"

[2020-11-23T09:45:42.108Z] ... expected string = "" +

[2020-11-23T09:45:42.108Z] ...     "[IndexLookUp_7 2048.00 root  ]\n" +

[2020-11-23T09:45:42.108Z] ...     "[├─IndexRangeScan_5(Build) 2048.00 cop[tikv] table:test, index:idx_age(age) range:[5,5], keep order:false]\n" +

[2020-11-23T09:45:42.108Z] ...     "[└─TableRowIDScan_6(Probe) 2048.00 cop[tikv] table:test keep order:false]\n"

Could you take a look?

[xiaodong-ji]

The test is often failed:

[2020-11-23T09:45:42.107Z] physical_plan_test.go:1731:

[2020-11-23T09:45:42.107Z]     tk.MustQuery("explain " + ts).Check(testkit.Rows(output[i].Plan...))

[2020-11-23T09:45:42.107Z] /home/jenkins/agent/workspace/tidb_ghpr_check_2/go/src/github.com/pingcap/tidb/util/testkit/testkit.go:63:

[2020-11-23T09:45:42.107Z]     res.c.Assert(resBuff.String(), check.Equals, needBuff.String(), res.comment)

[2020-11-23T09:45:42.107Z] ... obtained string = "" +

[2020-11-23T09:45:42.107Z] ...     "[IndexLookUp_7 1441.12 root  ]\n" +

[2020-11-23T09:45:42.107Z] ...     "[├─IndexRangeScan_5(Build) 1441.12 cop[tikv] table:test, index:idx_age(age) range:[5,5], keep order:false]\n" +

[2020-11-23T09:45:42.108Z] ...     "[└─TableRowIDScan_6(Probe) 1441.12 cop[tikv] table:test keep order:false]\n"

[2020-11-23T09:45:42.108Z] ... expected string = "" +

[2020-11-23T09:45:42.108Z] ...     "[IndexLookUp_7 2048.00 root  ]\n" +

[2020-11-23T09:45:42.108Z] ...     "[├─IndexRangeScan_5(Build) 2048.00 cop[tikv] table:test, index:idx_age(age) range:[5,5], keep order:false]\n" +

[2020-11-23T09:45:42.108Z] ...     "[└─TableRowIDScan_6(Probe) 2048.00 cop[tikv] table:test keep order:false]\n"

Could you take a look?

This error is caused by the wrong number of rows in the table