executor: disable paging for small limit (#41120)

[ti-chi-bot]

This is an automated cherry-pick of #41120

What problem does this PR solve?

Issue Number: close #40741

What is changed and how it works?

• disable paging for small limit DAG requests.

set @@tidb_enable_paging = 1;
use test;
drop table if exists ge1;

CREATE TABLE `ge1` (
  `actor_login` varchar(40) NOT NULL DEFAULT '',
  `id` bigint(20) NOT NULL DEFAULT '0',
  `type` varchar(29) NOT NULL DEFAULT 'Event',
  `action` varchar(11) NOT NULL DEFAULT '',
  `created_at` datetime NOT NULL DEFAULT '1970-01-01 00:00:00',
  `repo_id` bigint(20) NOT NULL DEFAULT '0',
  KEY (`repo_id`,`type`,`action`,`created_at`,`actor_login`))
PARTITION BY LIST COLUMNS(`type`)
( PARTITION `watch_event` VALUES IN ('WatchEvent'));

insert into ge1 value  ('xxy'        , 26332576530 , 'WatchEvent' , 'started' , '2023-01-10 12:00:06' , 41986369 ),
('DuWen'        , 26332576530 , 'WatchEvent' , 'started' , '2023-01-10 12:00:06' , 200039032 ),
('zzt'        , 26332576530 , 'WatchEvent' , 'started' , '2023-01-10 12:00:06' , 41986369 ),
('mmw'        , 26332576530 , 'WatchEvent' , 'started' , '2023-01-10 12:00:06' , 41986369 );

original

MySQL [test]> trace SELECT actor_login FROM ge1 WHERE type = 'WatchEvent' AND action = 'started' AND repo_id = 41986369 ORDER BY created_at limit 1;
+-------------------------------------------------------------------------+-----------------+------------+
| operation                                                               | startTS         | duration   |
+-------------------------------------------------------------------------+-----------------+------------+
| trace                                                                   | 02:00:03.937238 | 4.160278ms |
|   ├─session.ExecuteStmt                                                 | 02:00:03.937249 | 1.022849ms |
|   │ ├─executor.Compile                                                  | 02:00:03.937269 | 678.481µs  |
|   │ └─session.runStmt                                                   | 02:00:03.937989 | 248.746µs  |
|   │   └─distsql.Select                                                  | 02:00:03.938113 | 39.583µs   |
|   │     └─regionRequest.SendReqCtx                                      | 02:00:03.938255 | 978.998µs  |
|   │       ├─rpcClient.SendRequest, region ID: 15, type: Cop             | 02:00:03.938295 | 921.254µs  |
|   │       │ └─tikv.RPC                                                  | 02:00:03.938297 | 442.072µs  |
|   │       │   └─tikv.Wait                                               | 02:00:03.938297 | 77.812µs   |
|   │       │     └─tikv.GetSnapshot                                      | 02:00:03.938297 | 77.812µs   |
|   │       └─regionRequest.SendReqCtx                                    | 02:00:03.939272 | 577.443µs  |
|   │         ├─rpcClient.SendRequest, region ID: 15, type: Cop           | 02:00:03.939283 | 548.32µs   |
|   │         │ └─tikv.RPC                                                | 02:00:03.939284 | 190.851µs  |
|   │         │   └─tikv.Wait                                             | 02:00:03.939284 | 16.581µs   |
|   │         │     └─tikv.GetSnapshot                                    | 02:00:03.939284 | 16.581µs   |
|   │         └─regionRequest.SendReqCtx                                  | 02:00:03.939881 | 719.966µs  |
|   │           ├─rpcClient.SendRequest, region ID: 15, type: Cop         | 02:00:03.939891 | 675.607µs  |
|   │           │ └─tikv.RPC                                              | 02:00:03.939892 | 358.912µs  |
|   │           │   └─tikv.Wait                                           | 02:00:03.939892 | 37.794µs   |
|   │           │     └─tikv.GetSnapshot                                  | 02:00:03.939892 | 37.794µs   |
|   │           └─regionRequest.SendReqCtx                                | 02:00:03.940661 | 558.226µs  |
|   │             └─rpcClient.SendRequest, region ID: 15, type: Cop       | 02:00:03.940681 | 524.14µs   |
|   │               └─tikv.RPC                                            | 02:00:03.940682 | 213.454µs  |
|   │                 └─tikv.Wait                                         | 02:00:03.940682 | 19.889µs   |
|   │                   └─tikv.GetSnapshot                                | 02:00:03.940682 | 19.889µs   |
|   ├─*executor.ProjectionExec.Next                                       | 02:00:03.938283 | 3.030583ms |
|   │ └─*executor.TopNExec.Next                                           | 02:00:03.938286 | 3.016226ms |
|   │   ├─*executor.IndexReaderExecutor.Next                              | 02:00:03.938299 | 1.045114ms |
|   │   ├─*executor.IndexReaderExecutor.Next                              | 02:00:03.939370 | 1.897819ms |
|   │   └─*executor.IndexReaderExecutor.Next                              | 02:00:03.941282 | 5.307µs    |
|   └─*executor.ProjectionExec.Next                                       | 02:00:03.941323 | 18.616µs   |
|     └─*executor.TopNExec.Next                                           | 02:00:03.941325 | 12.205µs   |
+-------------------------------------------------------------------------+-----------------+------------+

MySQL [test]> explain analyze  SELECT actor_login FROM ge1 WHERE type = 'WatchEvent' AND action = 'started' AND repo_id = 41986369 ORDER BY created_at limit 1;
+-------------------------------+---------+---------+-----------+-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+-----------+------+
| id                            | estRows | actRows | task      | access object                                                                                   | execution info                                                                                                                                                                                                                       | operator info                                                                                           | memory    | disk |
+-------------------------------+---------+---------+-----------+-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+-----------+------+
| Projection_9                  | 0.00    | 1       | root      |                                                                                                 | time:2.86ms, loops:2, Concurrency:OFF                                                                                                                                                                                                | test.ge1.actor_login                                                                                    | 2.61 KB   | N/A  |
| └─TopN_10                     | 0.00    | 1       | root      |                                                                                                 | time:2.86ms, loops:2                                                                                                                                                                                                                 | test.ge1.created_at, offset:0, count:1                                                                  | 708 Bytes | N/A  |
|   └─IndexReader_17            | 0.00    | 3       | root      |                                                                                                 | time:2.82ms, loops:3, cop_task: {num: 4, max: 929.3µs, min: 536µs, avg: 670.4µs, p95: 929.3µs, max_proc_keys: 1, p95_proc_keys: 1, rpc_num: 4, rpc_time: 2.62ms, copr_cache_hit_ratio: 0.00, distsql_concurrency: 1}                 | index:Limit_16                                                                                          | 747 Bytes | N/A  |
|     └─Limit_16                | 0.00    | 3       | cop[tikv] |                                                                                                 | tikv_task:{proc max:0s, min:0s, avg: 0s, p80:0s, p95:0s, iters:4, tasks:4}, scan_detail: {total_process_keys: 3, total_process_keys_size: 459, total_keys: 7, get_snapshot_time: 118µs, rocksdb: {key_skipped_count: 3, block: {}}}  | offset:0, count:1                                                                                       | N/A       | N/A  |
|       └─IndexRangeScan_15     | 0.00    | 3       | cop[tikv] | table:ge1, partition:watch_event, index:repo_id(repo_id, type, action, created_at, actor_login) | tikv_task:{proc max:0s, min:0s, avg: 0s, p80:0s, p95:0s, iters:4, tasks:4}                                                                                                                                                           | range:[41986369 "WatchEvent" "started",41986369 "WatchEvent" "started"], keep order:false, stats:pseudo | N/A       | N/A  |
+-------------------------------+---------+---------+-----------+-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+-----------+------+

after

MySQL [test]> trace SELECT actor_login FROM ge1 WHERE type = 'WatchEvent' AND action = 'started' AND repo_id = 41986369 ORDER BY created_at limit 1;

+-------------------------------------------------------------------+-----------------+------------+
| operation                                                         | startTS         | duration   |
+-------------------------------------------------------------------+-----------------+------------+
| trace                                                             | 01:57:53.839381 | 1.999229ms |
|   ├─session.ExecuteStmt                                           | 01:57:53.839391 | 915.645µs  |
|   │ ├─executor.Compile                                            | 01:57:53.839412 | 551.257µs  |
|   │ └─session.runStmt                                             | 01:57:53.839999 | 271.472µs  |
|   │   └─distsql.Select                                            | 01:57:53.840137 | 38.047µs   |
|   │     └─regionRequest.SendReqCtx                                | 01:57:53.840288 | 906.74µs   |
|   │       └─rpcClient.SendRequest, region ID: 15, type: Cop       | 01:57:53.840321 | 857.697µs  |
|   │         └─tikv.RPC                                            | 01:57:53.840323 | 432.854µs  |
|   │           └─tikv.Wait                                         | 01:57:53.840323 | 170.02µs   |
|   │             └─tikv.GetSnapshot                                | 01:57:53.840323 | 170.02µs   |
|   ├─*executor.ProjectionExec.Next                                 | 01:57:53.840316 | 1.008551ms |
|   │ └─*executor.TopNExec.Next                                     | 01:57:53.840318 | 999.017µs  |
|   │   ├─*executor.IndexReaderExecutor.Next                        | 01:57:53.840328 | 920.367µs  |
|   │   └─*executor.IndexReaderExecutor.Next                        | 01:57:53.841277 | 30.717µs   |
|   └─*executor.ProjectionExec.Next                                 | 01:57:53.841333 | 10.162µs   |
|     └─*executor.TopNExec.Next                                     | 01:57:53.841335 | 831ns      |
+-------------------------------------------------------------------+-----------------+------------+

MySQL [test]> explain analyze  SELECT actor_login FROM ge1 WHERE type = 'WatchEvent' AND action = 'started' AND repo_id = 41986369 ORDER BY created_at limit 1;
+-------------------------------+---------+---------+-----------+-------------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+-----------+------+
| id                            | estRows | actRows | task      | access object                                                                                   | execution info                                                                                                                                                                           | operator info                                                                                           | memory    | disk |
+-------------------------------+---------+---------+-----------+-------------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+-----------+------+
| Projection_9                  | 0.00    | 1       | root      |                                                                                                 | time:955.7µs, loops:2, Concurrency:OFF                                                                                                                                                   | test.ge1.actor_login                                                                                    | 2.61 KB   | N/A  |
| └─TopN_10                     | 0.00    | 1       | root      |                                                                                                 | time:950.8µs, loops:2                                                                                                                                                                    | test.ge1.created_at, offset:0, count:1                                                                  | 708 Bytes | N/A  |
|   └─IndexReader_17            | 0.00    | 1       | root      |                                                                                                 | time:932µs, loops:2, cop_task: {num: 1, max: 847.4µs, proc_keys: 1, rpc_num: 1, rpc_time: 790.3µs, copr_cache_hit_ratio: 0.00, distsql_concurrency: 1}                                   | index:Limit_16                                                                                          | 387 Bytes | N/A  |
|     └─Limit_16                | 0.00    | 1       | cop[tikv] |                                                                                                 | tikv_task:{time:0s, loops:1}, scan_detail: {total_process_keys: 1, total_process_keys_size: 153, total_keys: 2, get_snapshot_time: 118.3µs, rocksdb: {key_skipped_count: 1, block: {}}}  | offset:0, count:1                                                                                       | N/A       | N/A  |
|       └─IndexRangeScan_15     | 0.00    | 1       | cop[tikv] | table:ge1, partition:watch_event, index:repo_id(repo_id, type, action, created_at, actor_login) | tikv_task:{time:0s, loops:1}                                                                                                                                                             | range:[41986369 "WatchEvent" "started",41986369 "WatchEvent" "started"], keep order:false, stats:pseudo | N/A       | N/A  |
+-------------------------------+---------+---------+-----------+-------------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+-----------+------+

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.

Fix the issue of performance regression that occurs when TiDB using `paging`

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• XuHuaiyu
• tiancaiamao

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[solotzg]

/test build

[tiancaiamao]

/merge

[ti-chi-bot]

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

Commit hash: e33dd4e

[ti-chi-bot]

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[solotzg]

/test unit-test

[XuHuaiyu]

/merge

[solotzg]

/test unit-test

[tiancaiamao]

/test unit-test