PLAN_TABLE_DATA
PLAN_TABLE_DATA stores plan information collected by EXPLAIN PLAN. Different from the PLAN_TABLE view, the system catalog PLAN_TABLE_DATA stores EXPLAIN PLAN information collected by all sessions and users.
| Name | Type | Description |
|---|---|---|
| session_id | text | Session that inserts the data. Its value consists of a service thread start timestamp and a service thread ID. Values are constrained by NOT NULL. |
| user_id | oid | User who inserts the data. Values are constrained by NOT NULL. |
| statement_id | character varying(30) | Query tag specified by a user |
| plan_id | bigint | Query plan ID. The ID is automatically generated in the plan generation phase and is used by kernel engineers for debugging. |
| id | integer | Node ID in a plan |
| operation | character varying(30) | Operation description |
| options | character varying(255) | Operation action |
| object_name | name | Name of an operated object. It is defined by users. |
| object_type | character varying(30) | Object type |
| object_owner | name | Schema to which an object belongs. It is defined by users. |
| projection | character varying(4000) | Returned column information |
| cost | double precision | Execution cost estimated by the optimizer for an operator |
| cardinality | double precision | Number of rows estimated by the optimizer for an operator |
- PLAN_TABLE_DATA records data of all users and sessions on the current node. Only administrators can access all the data. Common users can view their own data in the PLAN_TABLE view.
- Data of inactive (exited) sessions is cleaned from PLAN_TABLE_DATA by gs_clean after being stored in this system catalog for a certain period of time (5 minutes by default). You can also manually run gs_clean -C to delete inactive session data from the table.
- Data is automatically inserted into PLAN_TABLE_DATA after EXPLAIN PLAN is executed. Therefore, do not manually insert data into or update data in PLAN_TABLE_DATA. Otherwise, data in PLAN_TABLE_DATA may be disordered. When you need to delete data from a table, it is recommended that you use the PLAN_TABLE view.
- Information in the statement_id, object_name, object_owner, and projection columns is stored in letter cases specified by users and information in other columns is stored in uppercase.
