Note
This view was introduced in V3.2.1.
Purpose
This view displays the histogram information of the partitions of the current user.
Applicability
This view is applicable only to OceanBase Database in Oracle mode.
Columns
| Column | Type | Nullable | Description |
|---|---|---|---|
| TABLE_NAME | VARCHAR2(128) | NO | The name of the table to which the histogram belongs. |
| PARTITION_NAME | VARCHAR2(128) | NO | The name of the partition to which the histogram belongs. |
| COLUMN_NAME | VARCHAR2(128) | NO | The name of the column to which the histogram belongs. |
| ENDPOINT_NUMBER | NUMBER | NO | The cumulative frequency of the bucket. |
| ENDPOINT_VALUE | NUMBER | NO | The normalized value of the bucket endpoint. |
| ENDPOINT_ACTUAL_VALUE | VARCHAR2(4000) | NO | The endpoint value of the bucket. |
| ENDPOINT_ACTUAL_VALUE_RAW | VARCHAR2(4000) | NO | The binary value of the bucket endpoint. |
| ENDPOINT_REPEAT_COUNT | NUMBER | NO | The frequency of the bucket endpoint value. |
Sample query
Query the histogram information of the partitions of the T_SUBPART table in the partitioned tables owned by the current user.
obclient [SYS]> SELECT * FROM SYS.USER_PART_HISTOGRAMS WHERE TABLE_NAME ='T_SUBPART';
The query result is as follows:
+------------+----------------+-------------+-----------------+----------------+-----------------------+---------------------------+-----------------------+
| TABLE_NAME | PARTITION_NAME | COLUMN_NAME | ENDPOINT_NUMBER | ENDPOINT_VALUE | ENDPOINT_ACTUAL_VALUE | ENDPOINT_ACTUAL_VALUE_RAW | ENDPOINT_REPEAT_COUNT |
+------------+----------------+-------------+-----------------+----------------+-----------------------+---------------------------+-----------------------+
| T_SUBPART | P1 | ID | 50 | NULL | 1 | 1 | 50 |
| T_SUBPART | P1 | ID | 100 | NULL | 2 | 2 | 50 |
| T_SUBPART | P1 | ID | 150 | NULL | 3 | 3 | 50 |
| T_SUBPART | P1 | ID | 200 | NULL | 4 | 4 | 50 |
| T_SUBPART | P1 | ID | 250 | NULL | 5 | 5 | 50 |
| T_SUBPART | P1 | ID | 300 | NULL | 6 | 6 | 50 |
| T_SUBPART | P1 | ID | 350 | NULL | 7 | 7 | 50 |
| T_SUBPART | P1 | ID | 400 | NULL | 8 | 8 | 50 |
| T_SUBPART | P1 | ID | 450 | NULL | 9 | 9 | 50 |
| T_SUBPART | P1 | ID | 500 | NULL | 999 | 999 | 50 |
| T_SUBPART | P1 | QUANTITY | 495 | NULL | 1 | 1 | 495 |
| T_SUBPART | P1 | QUANTITY | 500 | NULL | 1000 | 1000 | 5 |
| T_SUBPART | P2 | ID | 30 | NULL | 1 | 1 | 30 |
| T_SUBPART | P2 | ID | 60 | NULL | 2 | 2 | 30 |
| T_SUBPART | P2 | ID | 90 | NULL | 3 | 3 | 30 |
| T_SUBPART | P2 | ID | 120 | NULL | 4 | 4 | 30 |
| T_SUBPART | P2 | ID | 150 | NULL | 5 | 5 | 30 |
| T_SUBPART | P2 | ID | 180 | NULL | 6 | 6 | 30 |
| T_SUBPART | P2 | ID | 210 | NULL | 7 | 7 | 30 |
| T_SUBPART | P2 | ID | 240 | NULL | 8 | 8 | 30 |
| T_SUBPART | P2 | ID | 270 | NULL | 9 | 9 | 30 |
| T_SUBPART | P2 | ID | 300 | NULL | 999 | 999 | 30 |
| T_SUBPART | P2 | QUANTITY | 297 | NULL | 1 | 1 | 297 |
| T_SUBPART | P2 | QUANTITY | 300 | NULL | 1000 | 1000 | 3 |
| T_SUBPART | P3 | ID | 20 | NULL | 1 | 1 | 20 |
| T_SUBPART | P3 | ID | 40 | NULL | 2 | 2 | 20 |
| T_SUBPART | P3 | ID | 60 | NULL | 3 | 3 | 20 |
| T_SUBPART | P3 | ID | 80 | NULL | 4 | 4 | 20 |
| T_SUBPART | P3 | ID | 100 | NULL | 5 | 5 | 20 |
| T_SUBPART | P3 | ID | 120 | NULL | 6 | 6 | 20 |
| T_SUBPART | P3 | ID | 140 | NULL | 7 | 7 | 20 |
| T_SUBPART | P3 | ID | 160 | NULL | 8 | 8 | 20 |
| T_SUBPART | P3 | ID | 180 | NULL | 9 | 9 | 20 |
| T_SUBPART | P3 | ID | 200 | NULL | 999 | 999 | 20 |
| T_SUBPART | P3 | QUANTITY | 198 | NULL | 1 | 1 | 198 |
| T_SUBPART | P3 | QUANTITY | 200 | NULL | 1000 | 1000 | 2 |
+------------+----------------+-------------+-----------------+----------------+-----------------------+---------------------------+-----------------------+
36 rows in set
References
View the histograms of partitions of partitioned tables accessible to the current user: ALL_PART_HISTOGRAMS
View the histograms of partitions of all partitioned tables in the current tenant: DBA_PART_HISTOGRAMS
View table-level histogram statistics by querying the following views:
View subpartition-level histogram statistics by querying the following views:
View table-level column statistics by querying the following views:
View global column statistics by querying the following views:
View partition-level column statistics by querying the following views:
View subpartition-level column statistics by querying the following views:
View index statistics by querying the following views:
For more information about how to collect statistics, see the following topics:
