*: global stats consistency for dynamic prune

[chrysan]

What problem does this PR solve?

Issue Number: close #34730

Problem Summary:
Refine the logic of analyze under dynamic prune mode, to avoid inconsistency between partition stats and global stats.
In static mode, we may have different column settings and different persisted analyze options for partitions. That's the root cause of inconsistency.

What is changed and how it works?

mysql> create table t (a int, b int, c int) partition by range (a) (partition p0 values less than (10), partition p1 values less than (20));
Query OK, 0 rows affected (0.00 sec)

mysql> insert into t values (1,1,1), (2,2,2), (11,11,11);
Query OK, 3 rows affected (0.00 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql> set tidb_partition_prune_mode=dynamic;
Query OK, 0 rows affected (0.00 sec)

mysql> analyze table t partition p0 columns b with 1 topn, 1 buckets;
Query OK, 0 rows affected, 2 warnings (0.05 sec)

mysql> show warnings;
+---------+------+--------------------------------------------------------------------------------+
| Level   | Code | Message                                                                        |
+---------+------+--------------------------------------------------------------------------------+
| Warning | 1105 | Ignore columns and options when analyze partition in dynamic mode              |
| Note    | 1105 | Analyze use auto adjusted sample rate 1.000000 for table test.t's partition p0 |
+---------+------+--------------------------------------------------------------------------------+
2 rows in set (0.00 sec)

mysql> analyze table t partition p1 columns c with 1 topn, 1 buckets;
Query OK, 0 rows affected, 2 warnings (0.04 sec)

mysql> show warnings;
+---------+------+--------------------------------------------------------------------------------+
| Level   | Code | Message                                                                        |
+---------+------+--------------------------------------------------------------------------------+
| Warning | 1105 | Ignore columns and options when analyze partition in dynamic mode              |
| Note    | 1105 | Analyze use auto adjusted sample rate 1.000000 for table test.t's partition p1 |
+---------+------+--------------------------------------------------------------------------------+
2 rows in set (0.00 sec)

mysql> select * from t where b>1 and c>1;

mysql> show stats_histograms where table_name like "t";
+---------+------------+----------------+-------------+----------+---------------------+----------------+------------+--------------+-------------+
| Db_name | Table_name | Partition_name | Column_name | Is_index | Update_time         | Distinct_count | Null_count | Avg_col_size | Correlation |
+---------+------------+----------------+-------------+----------+---------------------+----------------+------------+--------------+-------------+
| test    | t          | global         | b           |        0 | 2022-05-17 15:00:56 |              3 |          0 |          0.5 |           0 |
| test    | t          | global         | c           |        0 | 2022-05-17 15:00:56 |              3 |          0 |          0.5 |           0 |
+---------+------------+----------------+-------------+----------+---------------------+----------------+------------+--------------+-------------+
2 rows in set (0.00 sec)

BTW:

mysql> set tidb_partition_prune_mode=dynamic;
Query OK, 0 rows affected, 1 warning (2.25 sec)

mysql> show warnings;
+---------+------+----------------------------------------------------------------------------------------------+
| Level   | Code | Message                                                                                      |
+---------+------+----------------------------------------------------------------------------------------------+
| Warning | 1105 | Please analyze all partition tables again for consistency between partition and global stats |
+---------+------+----------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

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:

• Yisaer
• xuyifangreeneyes

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[sre-bot]

Code Coverage Details: https://codecov.io/github/pingcap/tidb/commit/3b562a7912cd85b00ab33faaab4cadfb26de3d4f

[Yisaer]

I found that there exists lots of duplciated assertion code in unit test, can we extract it as common function?

[xuyifangreeneyes]

rest LGTM

[chrysan]

I found that there exists lots of duplciated assertion code in unit test, can we extract it as common function?

Not too many in common, prefer to keep the flexibility.

[chrysan]

/merge

[ti-chi-bot]

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

Commit hash: bbc8b81

[sre-bot]

TiDB MergeCI notify

🔴 Bad News! [1] CI still failing after this pr merged.
These failed integration tests don't seem to be introduced by the current PR.

CI Name	Result	Duration	Compare with Parent commit
idc-jenkins-ci/integration-cdc-test	🔴 failed 1, success 33, total 34	29 min	Existing failure
idc-jenkins-ci-tidb/integration-common-test	🟢 all 11 tests passed	11 min	Existing passed
idc-jenkins-ci-tidb/integration-compatibility-test	🟢 all 1 tests passed	6 min 32 sec	Existing passed
idc-jenkins-ci-tidb/tics-test	🟢 all 1 tests passed	6 min 1 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-2	🟢 all 28 tests passed	5 min 51 sec	Existing passed
idc-jenkins-ci-tidb/common-test	🟢 all 12 tests passed	5 min 40 sec	Existing passed
idc-jenkins-ci-tidb/integration-ddl-test	🟢 all 6 tests passed	5 min 40 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-1	🟢 all 26 tests passed	5 min 30 sec	Existing passed
idc-jenkins-ci-tidb/mybatis-test	🟢 all 1 tests passed	3 min 34 sec	Existing passed
idc-jenkins-ci-tidb/plugin-test	🟢 build success, plugin test success	4min	Existing passed