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