OceanBase統計情報管理実践ガイド

本ガイドでは、完全なサンプルを通じて、OceanBaseにおけるテーブルの統計情報の収集、クエリ、エクスポート、復元、および管理方法を説明します。これには、テーブル構造の作成、統計情報の操作、履歴管理までの全プロセスが含まれます。

以下のサンプルは、デフォルトでMySQLモードに基づいています。Oracleモードでも操作方法は完全に互換性があり、関連する内容は省略します。

ステップ1：テストテーブルを作成し、データを挿入する

obclient> CREATE TABLE test.t_subpart (c1 INT, c2 INT, c3 INT) PARTITION BY HASH(c1)
   SUBPARTITION BY HASH(c2)
   SUBPARTITION TEMPLATE
    (
      SUBPARTITION sp0,
      SUBPARTITION sp1,
      SUBPARTITION sp2
    )
    PARTITIONS 3;
Query OK, 0 rows affected

obclient> INSERT INTO test.t_subpart WITH RECURSIVE numbers AS (SELECT 0 AS n UNION ALL
 SELECT n + 1 FROM numbers WHERE n < 999
 )
 SELECT n, MOD(n, 1000), MOD(n, 2000) FROM numbers;
Query OK, 10000 rows affected
Records: 10000  Duplicates: 0  Warnings: 0

obclient> SELECT COUNT(*) FROM test.t_subpart;
+----------+
| COUNT(*) |
+----------+
|    10000 |
+----------+
1 row in set

ステップ2：テーブルの統計情報を収集する

obclient> CALL DBMS_STATS.GATHER_TABLE_STATS('test', 't_subpart', method_opt=>'FOR ALL COLUMNS SIZE 5', granularity=>'ALL', degree=>4);
Query OK, 0 rows affected

ステップ3：統計情報のクエリ

1. テーブルレベルの統計情報をクエリします。

   obclient> SELECT TABLE_NAME, OBJECT_TYPE, NUM_ROWS, AVG_ROW_LEN FROM oceanbase.DBA_TAB_STATISTICS WHERE TABLE_NAME = 'T_SUBPART' AND OWNER = 'TEST' ORDER BY 1, 2, 3;
   +------------+--------------+----------+-------------+
   | TABLE_NAME | OBJECT_TYPE  | NUM_ROWS | AVG_ROW_LEN |
   +------------+--------------+----------+-------------+
   | t_subpart  | PARTITION    |      333 |          60 |
   | t_subpart  | PARTITION    |      333 |          60 |
   | t_subpart  | PARTITION    |      334 |          60 |
   | t_subpart  | SUBPARTITION |        0 |           0 |
   | t_subpart  | SUBPARTITION |        0 |           0 |
   | t_subpart  | SUBPARTITION |        0 |           0 |
   | t_subpart  | SUBPARTITION |        0 |           0 |
   | t_subpart  | SUBPARTITION |        0 |           0 |
   | t_subpart  | SUBPARTITION |        0 |           0 |
   | t_subpart  | SUBPARTITION |      333 |          60 |
   | t_subpart  | SUBPARTITION |      333 |          60 |
   | t_subpart  | SUBPARTITION |      334 |          60 |
   | t_subpart  | TABLE        |     1000 |          60 |
   +------------+--------------+----------+-------------+
   13 rows in set
   

2. 列レベルの統計情報をクエリします。

   obclient> SELECT TABLE_NAME, COLUMN_NAME, NUM_DISTINCT, LOW_VALUE, HIGH_VALUE, DENSITY, NUM_NULLS, NUM_BUCKETS, SAMPLE_SIZE, AVG_COL_LEN, HISTOGRAM FROM oceanbase.DBA_TAB_COL_STATISTICS WHERE table_name ='T_SUBPART' AND OWNER = 'TEST' ORDER BY 1, 2, 3;
   ++------------+-------------+--------------+-----------+------------+---------+-----------+-------------+-------------+-------------+-----------+
   | TABLE_NAME | COLUMN_NAME | NUM_DISTINCT | LOW_VALUE | HIGH_VALUE | DENSITY | NUM_NULLS | NUM_BUCKETS | SAMPLE_SIZE | AVG_COL_LEN | HISTOGRAM |
   +------------+-------------+--------------+-----------+------------+---------+-----------+-------------+-------------+-------------+-----------+
   | t_subpart  | c1          |         1012 | 0         | 999        |       0 |         0 |           5 |        1000 |          20 | HYBRID    |
   | t_subpart  | c2          |         1012 | 0         | 999        |       0 |         0 |           5 |        1000 |          20 | HYBRID    |
   | t_subpart  | c3          |         1012 | 0         | 999        |       0 |         0 |           5 |        1000 |          20 | HYBRID    |
   +------------+-------------+--------------+-----------+------------+---------+-----------+-------------+-------------+-------------+-----------+
   3 rows in set
   
   obclient> SELECT TABLE_NAME, PARTITION_NAME, COLUMN_NAME, ENDPOINT_NUMBER, ENDPOINT_VALUE, ENDPOINT_ACTUAL_VALUE, ENDPOINT_ACTUAL_VALUE_RAW, ENDPOINT_REPEAT_COUNT from oceanbase.DBA_PART_HISTOGRAMS WHERE table_name ='T_SUBPART' AND OWNER = 'TEST' ORDER BY 1, 2, 3;
   +------------+----------------+-------------+-----------------+----------------+-----------------------+---------------------------+-----------------------+
   | TABLE_NAME | PARTITION_NAME | COLUMN_NAME | ENDPOINT_NUMBER | ENDPOINT_VALUE | ENDPOINT_ACTUAL_VALUE | ENDPOINT_ACTUAL_VALUE_RAW | ENDPOINT_REPEAT_COUNT |
   +------------+----------------+-------------+-----------------+----------------+-----------------------+---------------------------+-----------------------+
   | t_subpart  | p0             | c1          |               1 |           NULL | 0                     | 04053F0000                |                     1 |
   | t_subpart  | p0             | c1          |             334 |           NULL | 999                   | 04053F00E707              |                     1 |
   | t_subpart  | p0             | c1          |              85 |           NULL | 252                   | 04053F00FC01              |                     1 |
   | t_subpart  | p0             | c1          |             252 |           NULL | 753                   | 04053F00F105              |                     1 |
   | t_subpart  | p0             | c1          |             169 |           NULL | 504                   | 04053F00F803              |                     1 |
   | t_subpart  | p0             | c2          |              85 |           NULL | 252                   | 04053F00FC01              |                     1 |
   | t_subpart  | p0             | c2          |               1 |           NULL | 0                     | 04053F0000                |                     1 |
   | t_subpart  | p0             | c2          |             169 |           NULL | 504                   | 04053F00F803              |                     1 |
   | t_subpart  | p0             | c2          |             252 |           NULL | 753                   | 04053F00F105              |                     1 |
   | t_subpart  | p0             | c2          |             334 |           NULL | 999                   | 04053F00E707              |                     1 |
   | t_subpart  | p0             | c3          |             334 |           NULL | 999                   | 04053F00E707              |                     1 |
   | t_subpart  | p0             | c3          |               1 |           NULL | 0                     | 04053F0000                |                     1 |
   | t_subpart  | p0             | c3          |              85 |           NULL | 252                   | 04053F00FC01              |                     1 |
   | t_subpart  | p0             | c3          |             169 |           NULL | 504                   | 04053F00F803              |                     1 |
   | t_subpart  | p0             | c3          |             252 |           NULL | 753                   | 04053F00F105              |                     1 |
   | t_subpart  | p1             | c1          |             251 |           NULL | 751                   | 04053F00EF05              |                     1 |
   | t_subpart  | p1             | c1          |             333 |           NULL | 997                   | 04053F00E507              |                     1 |
   | t_subpart  | p1             | c1          |             168 |           NULL | 502                   | 04053F00F603              |                     1 |
   | t_subpart  | p1             | c1          |              85 |           NULL | 253                   | 04053F00FD01              |                     1 |
   | t_subpart  | p1             | c1          |               1 |           NULL | 1                     | 04053F0001                |                     1 |
   | t_subpart  | p1             | c2          |             333 |           NULL | 997                   | 04053F00E507              |                     1 |
   | t_subpart  | p1             | c2          |             251 |           NULL | 751                   | 04053F00EF05              |                     1 |
   | t_subpart  | p1             | c2          |               1 |           NULL | 1                     | 04053F0001                |                     1 |
   | t_subpart  | p1             | c2          |             168 |           NULL | 502                   | 04053F00F603              |                     1 |
   | t_subpart  | p1             | c2          |              85 |           NULL | 253                   | 04053F00FD01              |                     1 |
   | t_subpart  | p1             | c3          |             333 |           NULL | 997                   | 04053F00E507              |                     1 |
   | t_subpart  | p1             | c3          |             251 |           NULL | 751                   | 04053F00EF05              |                     1 |
   | t_subpart  | p1             | c3          |             168 |           NULL | 502                   | 04053F00F603              |                     1 |
   | t_subpart  | p1             | c3          |              85 |           NULL | 253                   | 04053F00FD01              |                     1 |
   | t_subpart  | p1             | c3          |               1 |           NULL | 1                     | 04053F0001                |                     1 |
   | t_subpart  | p2             | c1          |             251 |           NULL | 752                   | 04053F00F005              |                     1 |
   | t_subpart  | p2             | c1          |               1 |           NULL | 2                     | 04053F0002                |                     1 |
   | t_subpart  | p2             | c1          |              85 |           NULL | 254                   | 04053F00FE01              |                     1 |
   | t_subpart  | p2             | c1          |             168 |           NULL | 503                   | 04053F00F703              |                     1 |
   | t_subpart  | p2             | c1          |             333 |           NULL | 998                   | 04053F00E607              |                     1 |
   | t_subpart  | p2             | c2          |              85 |           NULL | 254                   | 04053F00FE01              |                     1 |
   | t_subpart  | p2             | c2          |             333 |           NULL | 998                   | 04053F00E607              |                     1 |
   | t_subpart  | p2             | c2          |               1 |           NULL | 2                     | 04053F0002                |                     1 |
   | t_subpart  | p2             | c2          |             251 |           NULL | 752                   | 04053F00F005              |                     1 |
   | t_subpart  | p2             | c2          |             168 |           NULL | 503                   | 04053F00F703              |                     1 |
   | t_subpart  | p2             | c3          |              85 |           NULL | 254                   | 04053F00FE01              |                     1 |
   | t_subpart  | p2             | c3          |             168 |           NULL | 503                   | 04053F00F703              |                     1 |
   | t_subpart  | p2             | c3          |               1 |           NULL | 2                     | 04053F0002                |                     1 |
   | t_subpart  | p2             | c3          |             251 |           NULL | 752                   | 04053F00F005              |                     1 |
   | t_subpart  | p2             | c3          |             333 |           NULL | 998                   | 04053F00E607              |                     1 |
   

+------------+----------------+-------------+-----------------+----------------+-----------------------+---------------------------+-----------------------+ 45 rows in set

## ステップ4：統計情報ユーザーテーブルを作成する

```sql
obclient> CALL DBMS_STATS.CREATE_STAT_TABLE('test', 'test_stat');
Query OK, 0 rows affected

obclient> DESC test.test_stat;
+----------+---------------+------+------+---------+-------+
| Field    | Type          | Null | Key  | Default | Extra |
+----------+---------------+------+------+---------+-------+
| STATID   | varchar(128)  | YES  |      | NULL    |       |
| TYPE     | char(1)       | YES  |      | NULL    |       |
| VERSION  | decimal(10,0) | YES  |      | NULL    |       |
| FLAGS    | decimal(10,0) | YES  |      | NULL    |       |
| C1       | varchar(128)  | YES  |      | NULL    |       |
| C2       | varchar(128)  | YES  |      | NULL    |       |
| C3       | varchar(128)  | YES  |      | NULL    |       |
| C4       | varchar(128)  | YES  |      | NULL    |       |
| C5       | varchar(128)  | YES  |      | NULL    |       |
| C6       | varchar(128)  | YES  |      | NULL    |       |
| N1       | decimal(10,0) | YES  |      | NULL    |       |
| N2       | double        | YES  |      | NULL    |       |
| N3       | decimal(10,0) | YES  |      | NULL    |       |
| N4       | decimal(10,0) | YES  |      | NULL    |       |
| N5       | decimal(10,0) | YES  |      | NULL    |       |
| N6       | decimal(10,0) | YES  |      | NULL    |       |
| N7       | decimal(10,0) | YES  |      | NULL    |       |
| N8       | decimal(10,0) | YES  |      | NULL    |       |
| N9       | decimal(10,0) | YES  |      | NULL    |       |
| N10      | decimal(10,0) | YES  |      | NULL    |       |
| N11      | decimal(10,0) | YES  |      | NULL    |       |
| N12      | decimal(10,0) | YES  |      | NULL    |       |
| N13      | decimal(10,0) | YES  |      | NULL    |       |
| D1       | timestamp(6)  | YES  |      | NULL    |       |
| T1       | timestamp     | YES  |      | NULL    |       |
| R1       | text          | YES  |      | NULL    |       |
| R2       | text          | YES  |      | NULL    |       |
| R3       | text          | YES  |      | NULL    |       |
| CH1      | varchar(1000) | YES  |      | NULL    |       |
| CL1      | blob          | YES  |      | NULL    |       |
| BL1      | blob          | YES  |      | NULL    |       |
| OB_SPEC1 | decimal(10,0) | YES  |      | NULL    |       |
| OB_SPEC2 | decimal(10,0) | YES  |      | NULL    |       |
| OB_SPEC3 | varchar(4096) | YES  |      | NULL    |       |
+----------+---------------+------+------+---------+-------+
34 rows in set

ステップ5：統計情報のエクスポートとインポート

1. 統計情報をユーザーテーブルにエクスポートします。

   obclient> CALL DBMS_STATS.EXPORT_TABLE_STATS('test', 't_subpart', stattab=>'test_stat', statown=>'test');
   Query OK, 0 rows affected
   
   obclient> SELECT COUNT(*) FROM test.test_stat;
   +----------+
   | COUNT(*) |
   +----------+
   |      136 |
   +----------+
   1 row in set
   

2. 統計情報を削除します。

   obclient> CALL DBMS_STATS.DELETE_TABLE_STATS('test', 't_subpart');
   Query OK, 0 rows affected
   
   obclient> SELECT TABLE_NAME, OBJECT_TYPE, NUM_ROWS, AVG_ROW_LEN FROM oceanbase.DBA_TAB_STATISTICS WHERE table_name = 'T_SUBPART' and OWNER = 'TEST' ORDER BY 1, 2, 3;
   +------------+--------------+----------+-------------+
   | TABLE_NAME | OBJECT_TYPE  | NUM_ROWS | AVG_ROW_LEN |
   +------------+--------------+----------+-------------+
   | T_SUBPART  | PARTITION    |     NULL |        NULL |
   | T_SUBPART  | PARTITION    |     NULL |        NULL |
   | T_SUBPART  | PARTITION    |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | TABLE        |     NULL |        NULL |
   +------------+--------------+----------+-------------+
   13 rows in set
   

3. 統計情報を設定します。

   obclient> CALL DBMS_STATS.SET_TABLE_STATS('test', 't_subpart', numrows=>10000);
   Query OK, 0 rows affected
   
   obclient> SELECT TABLE_NAME, OBJECT_TYPE, NUM_ROWS, AVG_ROW_LEN FROM oceanbase.DBA_TAB_STATISTICS WHERE table_name = 'T_SUBPART' AND OWNER = 'TEST' ORDER BY 1, 2, 3;
   +------------+--------------+----------+-------------+
   | TABLE_NAME | OBJECT_TYPE  | NUM_ROWS | AVG_ROW_LEN |
   +------------+--------------+----------+-------------+
   | T_SUBPART  | PARTITION    |     NULL |        NULL |
   | T_SUBPART  | PARTITION    |     NULL |        NULL |
   | T_SUBPART  | PARTITION    |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | SUBPARTITION |     NULL |        NULL |
   | T_SUBPART  | TABLE        |    10000 |           0 |
   +------------+--------------+----------+-------------+
   13 rows in set
   

ステップ6：統計情報のロックとアンロック

1. 統計情報をロックします。

   obclient> CALL DBMS_STATS.LOCK_TABLE_STATS('test', 't_subpart');
   Query OK, 0 rows affected
   
   obclient> SELECT TABLE_NAME, OBJECT_TYPE, NUM_ROWS, AVG_ROW_LEN,STATTYPE_LOCKED FROM oceanbase.DBA_TAB_STATISTICS WHERE table_name = 'T_SUBPART' and OWNER = 'TEST' ORDER BY 1, 2, 3;
   +------------+--------------+----------+-------------+-----------------+
   | TABLE_NAME | OBJECT_TYPE  | NUM_ROWS | AVG_ROW_LEN | STATTYPE_LOCKED |
   +------------+--------------+----------+-------------+-----------------+
   | T_SUBPART  | PARTITION    |        0 |           0 | ALL             |
   | T_SUBPART  | PARTITION    |        0 |           0 | ALL             |
   | T_SUBPART  | PARTITION    |        0 |           0 | ALL             |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | ALL             |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | ALL             |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | ALL             |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | ALL             |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | ALL             |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | ALL             |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | ALL             |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | ALL             |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | ALL             |
   | T_SUBPART  | TABLE        |    10000 |           0 | ALL             |
   +------------+--------------+----------+-------------+-----------------+
   13 rows in set
   
   obclient> CALL DBMS_STATS.GATHER_TABLE_STATS('test', 't_subpart', method_opt=>'FOR ALL COLUMNS SIZE 5', granularity=>'ALL', degree=>4);
   ERROR 5935 (HY000): object statistics are locked
   

2. 統計情報のロックを解除します。

   obclient> CALL DBMS_STATS.UNLOCK_TABLE_STATS('test', 't_subpart');
   Query OK, 0 rows affected
   
   obclient> SELECT TABLE_NAME, OBJECT_TYPE, NUM_ROWS, AVG_ROW_LEN,STATTYPE_LOCKED FROM oceanbase.DBA_TAB_STATISTICS WHERE table_name = 'T_SUBPART' AND OWNER = 'TEST' ORDER BY 1, 2, 3;
   +------------+--------------+----------+-------------+-----------------+
   | TABLE_NAME | OBJECT_TYPE  | NUM_ROWS | AVG_ROW_LEN | STATTYPE_LOCKED |
   +------------+--------------+----------+-------------+-----------------+
   | T_SUBPART  | PARTITION    |        0 |           0 | NULL            |
   | T_SUBPART  | PARTITION    |        0 |           0 | NULL            |
   | T_SUBPART  | PARTITION    |        0 |           0 | NULL            |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | NULL            |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | NULL            |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | NULL            |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | NULL            |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | NULL            |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | NULL            |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | NULL            |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | NULL            |
   | T_SUBPART  | SUBPARTITION |        0 |           0 | NULL            |
   | T_SUBPART  | TABLE        |    10000 |           0 | NULL            |
   +------------+--------------+----------+-------------+-----------------+
   13 rows in set
   

ステップ7：統計情報履歴の管理

1. 統計情報をインポートします。

   obclient> CALL DBMS_STATS.IMPORT_TABLE_STATS('test', 't_subpart', stattab=>'test_stat', statown=>'test');
   Query OK, 0 rows affected
   
   obclient> SELECT TABLE_NAME, OBJECT_TYPE, NUM_ROWS, AVG_ROW_LEN,STATTYPE_LOCKED FROM oceanbase.DBA_TAB_STATISTICS WHERE table_name = 'T_SUBPART' AND OWNER = 'TEST' ORDER BY 1, 2, 3;
   +------------+--------------+----------+-------------+-----------------+
   | TABLE_NAME | OBJECT_TYPE  | NUM_ROWS | AVG_ROW_LEN | STATTYPE_LOCKED |
   +------------+--------------+----------+-------------+-----------------+
   | t_subpart  | PARTITION    |      333 |          60 | NULL            |
   | t_subpart  | PARTITION    |      333 |          60 | NULL            |
   | t_subpart  | PARTITION    |      334 |          60 | NULL            |
   | t_subpart  | SUBPARTITION |        0 |           0 | NULL            |
   | t_subpart  | SUBPARTITION |        0 |           0 | NULL            |
   | t_subpart  | SUBPARTITION |        0 |           0 | NULL            |
   | t_subpart  | SUBPARTITION |        0 |           0 | NULL            |
   | t_subpart  | SUBPARTITION |        0 |           0 | NULL            |
   | t_subpart  | SUBPARTITION |        0 |           0 | NULL            |
   | t_subpart  | SUBPARTITION |      333 |          60 | NULL            |
   | t_subpart  | SUBPARTITION |      333 |          60 | NULL            |
   | t_subpart  | SUBPARTITION |      334 |          60 | NULL            |
   | t_subpart  | TABLE        |     1000 |          60 | NULL            |
   +------------+--------------+----------+-------------+-----------------+
   13 rows in set
   

2. 履歴の統計情報を復元します。

   obclient> SELECT * FROM oceanbase.DBA_TAB_STATS_HISTORY WHERE table_name = 'T_SUBPART' AND OWNER = 'TEST' ORDER BY STATS_UPDATE_TIME;
   +-------+------------+----------------+-------------------+----------------------------+
   | OWNER | TABLE_NAME | PARTITION_NAME | SUBPARTITION_NAME | STATS_UPDATE_TIME          |
   +-------+------------+----------------+-------------------+----------------------------+
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:44:51.248090 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:46:52.326696 |
   +-------+------------+----------------+-------------------+----------------------------+
   66 rows in set
   
   obclient> CALL DBMS_STATS.RESTORE_TABLE_STATS('test', 't_subpart', STR_TO_DATE('2025-06-18 22:03:22', '%Y-%m-%d %H:%i:%s'));
   Query OK, 0 rows affected
   
   obclient> SELECT TABLE_NAME, OBJECT_TYPE, NUM_ROWS, AVG_ROW_LEN, STATTYPE_LOCKED FROM oceanbase.DBA_TAB_STATISTICS WHERE table_name = 'T_SUBPART' and OWNER = 'TEST' ORDER BY 1, 2, 3;
   +-------+------------+----------------+-------------------+----------------------------+
   | OWNER | TABLE_NAME | PARTITION_NAME | SUBPARTITION_NAME | STATS_UPDATE_TIME          |
   +-------+------------+----------------+-------------------+----------------------------+
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:44:51.248090 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:46:52.326696 |
   +-------+------------+----------------+-------------------+----------------------------+
   66 rows in set
   

3. 履歴の統計情報を削除します。

   obclient> CALL DBMS_STATS.PURGE_STATS(STR_TO_DATE('2025-06-18 22:03:22', '%Y-%m-%d %H:%i:%s'));
   Query OK, 0 rows affected
   
   obclient> SELECT * FROM oceanbase.DBA_TAB_STATS_HISTORY WHERE table_name = 'T_SUBPART' AND OWNER = 'TEST' ORDER BY STATS_UPDATE_TIME;
   +-------+------------+----------------+-------------------+----------------------------+
   | OWNER | TABLE_NAME | PARTITION_NAME | SUBPARTITION_NAME | STATS_UPDATE_TIME          |
   +-------+------------+----------------+-------------------+----------------------------+
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:36:19.921257 |
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:44:21.186757 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:44:51.248090 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:45:20.504647 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:46:24.723984 |
   | test  | t_subpart  | NULL           | NULL              | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p2             | p2ssp1            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p1             | p1ssp0            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p2             | p2ssp0            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p0             | NULL              | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p2             | p2ssp2            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p1             | NULL              | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p2             | NULL              | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p1             | p1ssp1            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p0             | p0ssp2            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p1             | p1ssp2            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p0             | p0ssp1            | 2025-06-25 16:46:52.326696 |
   | test  | t_subpart  | p0             | p0ssp0            | 2025-06-25 16:46:52.326696 |
   +-------+------------+----------------+-------------------+----------------------------+
   66 rows in set