executor,sessionctx: enable coprocessor paging and make TestCoprocessorPagingSize stable

[tiancaiamao]

What problem does this PR solve?

Issue Number: close #38158

Problem Summary:

TestCoprocessorPagingSize assume the coprocessor paging protocol, otherwise it become unstable.

In #37920, the tidb_enable_paging default value is changed to false, to workaround a TPCH Q17 performance regression #37768.

Now that I've found the root cause #38012 of TPCH Q17, it can be change back.

What is changed and how it works?

Set @@tidb_enable_paging default to true and make TestCoprocessorPagingSize code more stable.

Check List

Tests

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

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

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• XuHuaiyu
• hawkingrei

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[hawkingrei]

/check-issue-triage-complete

[hawkingrei]

@tiancaiamao PTAL

    result.go:49: 
        	Error Trace:	/home/jenkins/.tidb/tmp/63a9840cd0739f2c243bb46478607469/sandbox/processwrapper-sandbox/6358/execroot/__main__/bazel-out/k8-fastbuild/bin/planner/core/core_test_/core_test.runfiles/__main__/planner/core/result.go:49
        	            				/home/jenkins/.tidb/tmp/63a9840cd0739f2c243bb46478607469/sandbox/processwrapper-sandbox/6358/execroot/__main__/bazel-out/k8-fastbuild/bin/planner/core/core_test_/core_test.runfiles/__main__/planner/core/physical_plan_test.go:2341
        	Error:      	Not equal: 
        	            	expected: "[Projection 250.00 root  test.ta.name, Column#13]\n[└─Apply 250.00 root  CARTESIAN left outer join]\n[  ├─IndexLookUp(Build) 250.00 root  ]\n[  │ ├─IndexRangeScan(Build) 250.00 cop[tikv] table:ta, index:idx_ta_name(name) range:[\"chad999\",\"chad99:\"), keep order:false, stats:pseudo]\n[  │ └─TableRowIDScan(Probe) 250.00 cop[tikv] table:ta keep order:false, stats:pseudo]\n[  └─MaxOneRow(Probe) 1.00 root  ]\n[    └─HashAgg 1.00 root  funcs:sum(Column#17)->Column#13]\n[      └─IndexLookUp 1.00 root  ]\n[        ├─IndexRangeScan(Build) 10.00 cop[tikv] table:tb, index:idx_tb_id(id) range: decided by [eq(test.ta.id, test.tb.id)], keep order:false, stats:pseudo]\n[        └─HashAgg(Probe) 1.00 cop[tikv]  funcs:sum(test.tb.code)->Column#17]\n[          └─TableRowIDScan 10.00 cop[tikv] table:tb keep order:false, stats:pseudo]\n"
        	            	actual  : "[Projection 250.00 root  test.ta.name, Column#13]\n[└─Apply 250.00 root  CARTESIAN left outer join]\n[  ├─IndexLookUp(Build) 250.00 root  ]\n[  │ ├─IndexRangeScan(Build) 250.00 cop[tikv] table:ta, index:idx_ta_name(name) range:[\"chad999\",\"chad99:\"), keep order:false, stats:pseudo]\n[  │ └─TableRowIDScan(Probe) 250.00 cop[tikv] table:ta keep order:false, stats:pseudo]\n[  └─MaxOneRow(Probe) 1.00 root  ]\n[    └─StreamAgg 1.00 root  funcs:sum(Column#21)->Column#13]\n[      └─Projection 10.00 root  cast(test.tb.code, decimal(10,0) BINARY)->Column#21]\n[        └─IndexLookUp 10.00 root  ]\n[          ├─IndexRangeScan(Build) 10.00 cop[tikv] table:tb, index:idx_tb_id(id) range: decided by [eq(test.ta.id, test.tb.id)], keep order:false, stats:pseudo]\n[          └─TableRowIDScan(Probe) 10.00 cop[tikv] table:tb keep order:false, stats:pseudo]\n"
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -6,7 +6,7 @@
        	            	 [  └─MaxOneRow(Probe) 1.00 root  ]
        	            	-[    └─HashAgg 1.00 root  funcs:sum(Column#17)->Column#13]
        	            	-[      └─IndexLookUp 1.00 root  ]
        	            	-[        ├─IndexRangeScan(Build) 10.00 cop[tikv] table:tb, index:idx_tb_id(id) range: decided by [eq(test.ta.id, test.tb.id)], keep order:false, stats:pseudo]
        	            	-[        └─HashAgg(Probe) 1.00 cop[tikv]  funcs:sum(test.tb.code)->Column#17]
        	            	-[          └─TableRowIDScan 10.00 cop[tikv] table:tb keep order:false, stats:pseudo]
        	            	+[    └─StreamAgg 1.00 root  funcs:sum(Column#21)->Column#13]
        	            	+[      └─Projection 10.00 root  cast(test.tb.code, decimal(10,0) BINARY)->Column#21]
        	            	+[        └─IndexLookUp 10.00 root  ]
        	            	+[          ├─IndexRangeScan(Build) 10.00 cop[tikv] table:tb, index:idx_tb_id(id) range: decided by [eq(test.ta.id, test.tb.id)], keep order:false, stats:pseudo]
        	            	+[          └─TableRowIDScan(Probe) 10.00 cop[tikv] table:tb keep order:false, stats:pseudo]
        	            	 
        	Test:       	TestNoDecorrelateHint
        	Messages:   	sql:explain format = 'brief' SELECT ta.NAME,(SELECT /*+ no_decorrelate() */ sum(tb.CODE) FROM tb WHERE ta.id = tb.id) tb_sum_code FROM ta WHERE ta.NAME LIKE 

[XuHuaiyu]

Is this affected by paging?

[tiancaiamao]

Yes, it seems that the optimizer consider the new plan is better with paging available.

[XuHuaiyu]

/merge

[ti-chi-bot]

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

Commit hash: 6abeb7e

[sre-bot]

TiDB MergeCI notify

🔴 Bad News! New failing [1] after this pr merged.
These new failed integration tests seem to be caused by the current PR, please try to fix these new failed integration tests, thanks!

CI Name	Result	Duration	Compare with Parent commit
idc-jenkins-ci-tidb/integration-ddl-test	🟥 failed 1, success 5, total 6	5 min 28 sec	New failing
idc-jenkins-ci-tidb/common-test	🔴 failed 1, success 10, total 11	16 min	Existing failure
idc-jenkins-ci/integration-cdc-test	🟢 all 37 tests passed	27 min	Existing passed
idc-jenkins-ci-tidb/integration-common-test	🟢 all 17 tests passed	12 min	Existing passed
idc-jenkins-ci-tidb/tics-test	🟢 all 1 tests passed	9 min 47 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-1	🟢 all 26 tests passed	5 min 5 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-2	🟢 all 28 tests passed	4 min 57 sec	Existing passed
idc-jenkins-ci-tidb/mybatis-test	🟢 all 1 tests passed	3 min 30 sec	Existing passed
idc-jenkins-ci-tidb/integration-compatibility-test	🟢 all 1 tests passed	2 min 47 sec	Existing passed
idc-jenkins-ci-tidb/plugin-test	🟢 build success, plugin test success	4min	Existing passed