sysvar: tidb_enable_column_tracking only takes effect when tidb_persist_analyze_options is turned on

[Rustin170506]

What problem does this PR solve?

In TiDB we have a global variable called tidb_persist_analyze_options, the default value is true, and it will help us to store the analyze options in the system table mysql.analyze_options.
We know that the Predicate Columns collection feature relies on this system to store the column selection. So if we set tidb_persist_analyze_options to false, the predicate column feature won't work anymore. Every time you need to explicitly ANALYZE TABLE table_name PREDICATE COLUMNS to make sure TiDB only analyses the predicate columns, otherwise auto-analyze it will keep analysing all columns.

So tidb_enable_column_tracking only takes effect when tidb_persist_analyze_options is turned on.

Issue Number: close #53478

Problem Summary:

What changed and how does it work?

I added some checks before we set tidb_enable_column_tracking and tidb_persist_analyze_options. Now, you can only turn on tidb_enable_column_tracking if tidb_persist_analyze_options is turned on.

1. tidb_persist_analyze_options cannot be turned on when tidb_enable_column_tracking is false.
2. tidb_persist_analyze_options cannot be turned off when tidb_enable_column_tracking is on.

Check List

Tests

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

  • I checked and no code files have been changed.

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.

Fixed an issue where tidb_enable_column_tracking may not work when tidb_persist_analyze_options is turned off
修复了 tidb_persist_analyze_options 关闭时可能导致 tidb_enable_column_tracking 无法工作的问题

[Rustin170506]

Tested locally:

1. Start the tidb cluster: tiup playground v8.0.0 --db.binpath /Users/hi-rustin/vsc/tidb/bin/tidb-server

mysql> select tidb_version();
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                                                                      |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v8.2.0-alpha-213-gbc145b3afa
Edition: Community
Git Commit Hash: bc145b3afa4c377792f887d08fb6e94e873929df
Git Branch: rustin-patch-tracking
UTC Build Time: 2024-05-22 08:45:27
GoVersion: go1.21.5
Race Enabled: false
Check Table Before Drop: false
Store: tikv |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

2. Set the tidb_enable_column_tracking to on first:

mysql> set global tidb_enable_column_tracking = 1;
Query OK, 0 rows affected (0.02 sec)

mysql> select @@tidb_enable_column_tracking;
+-------------------------------+
| @@tidb_enable_column_tracking |
+-------------------------------+
|                             1 |
+-------------------------------+
1 row in set (0.00 sec)

3. Try to turn off tidb_persist_analyze_options:

mysql> set global tidb_persist_analyze_options = 0;
ERROR 1105 (HY000): tidb_persist_analyze_options option cannot be set to OFF when tidb_enable_column_tracking is ON, as this will result in the loss of column tracking information

4. Turn off tidb_enable_column_tracking:

mysql> set global tidb_enable_column_tracking = 0;
Query OK, 0 rows affected (0.01 sec)

mysql> select @@tidb_enable_column_tracking;
+-------------------------------+
| @@tidb_enable_column_tracking |
+-------------------------------+
|                             0 |
+--------------------------

5. Turn off tidb_persist_analyze_options:

mysql> set global tidb_persist_analyze_options = 0;
Query OK, 0 rows affected (0.01 sec)

mysql> select @@tidb_persist_analyze_options;
+--------------------------------+
| @@tidb_persist_analyze_options |
+--------------------------------+
|                              0 |
+--------------------------------+
1 row in set (0.00 sec)

6. Try to turn on tidb_enable_column_tracking:

mysql> set global tidb_enable_column_tracking = 1;
ERROR 1105 (HY000): tidb_enable_column_tracking option cannot be set to ON when tidb_persist_analyze_options is set to OFF, as this will prevent the preservation of column tracking information

[codecov]

Codecov Report

Attention: Patch coverage is 89.65517% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 74.7481%. Comparing base (6928519) to head (0108b71).
Report is 11 commits behind head on master.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #53481        +/-   ##
================================================
+ Coverage   72.5278%   74.7481%   +2.2203%     
================================================
  Files          1505       1505                
  Lines        429901     430856       +955     
================================================
+ Hits         311798     322057     +10259     
+ Misses        98809      88950      -9859     
- Partials      19294      19849       +555     

Flag	Coverage Δ
integration	49.5734% <72.4137%> (?)
unit	71.4579% <89.6551%> (+0.0320%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
dumpling	53.9957% <ø> (ø)
parser	∅ <ø> (∅)
br	50.4742% <ø> (+9.0701%)	⬆️

[Rustin170506]

🔢 Self-check (PR reviewed by myself and ready for feedback.)

[Rustin170506]

I am not sure why do we need to check the stmt type here. Because we are already in the set func.

[elsa0520]

LGTM

[hawkingrei]

/test all

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-05-22 09:21:05.805735767 +0000 UTC m=+2249819.562871343: ☑️ agreed by elsa0520.
• 2024-05-23 07:38:32.483466312 +0000 UTC m=+2330066.240601882: ☑️ agreed by hawkingrei.

[easonn7]

/approve

For the short term, tidb_enable_column_tracking looks good to me, but for the long term, I believe only tidb_persist_analyze_options is reasonable. We don't need so many variables with complex dependencies.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: easonn7, elsa0520, hawkingrei

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Needs approval from an approver in each of these files:

• OWNERS [elsa0520,hawkingrei]
• pkg/sessionctx/variable/OWNERS [easonn7]

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[Rustin170506]

/retest

[Rustin170506]

/retest

[Rustin170506]

/retest

[Rustin170506]

/retest