STL_SAVE
Contains details for save steps in queries. A save step saves the input stream to a transient table. A transient table is a temporary table that stores intermediate results during query execution.
A query consists of multiple segments, and each segment consists of one or more steps. For more information, see Query processing.
STL_SAVE is visible to all users. Superusers can see all rows; regular users can see only their own data. For more information, see Visibility of data in system tables and views.
Note
STL_SAVE only contains queries run on main provisioned clusters. It doesn't contain queries run on concurrency scaling clusters or on serverless namespaces. To access explain plans for queries run on both main clusters, concurrency scaling clusters, and serverless namespaces, we recommend that you use the SYS monitoring view SYS_QUERY_DETAIL . The data in the SYS monitoring view is formatted to be easier to use and understand.
Table columns
| Column name | Data type | Description |
|---|---|---|
| userid | integer | ID of the user who generated the entry. |
| query | integer | Query ID. The query column can be used to join other system tables and views. |
| slice | integer | Number that identifies the slice where the query was running. |
| segment | integer | Number that identifies the query segment. |
| step | integer | Query step that ran. |
| starttime | timestamp | Time in UTC that the query started. Total time includes queuing and execution. with 6 digits of precision for fractional seconds. For example: 2009-06-12 11:29:19.131358. |
| endtime | timestamp | Time in UTC that the query finished. Total time includes queuing and execution. with 6 digits of precision for fractional seconds. For example: 2009-06-12 11:29:19.131358. |
| tasknum | integer | Number of the query task process that was assigned to run the step. |
| rows | bigint | Total number of rows that were processed. |
| bytes | bigint | Size, in bytes, of all the output rows for the step. |
| tbl | integer | ID of the materialized transient table. |
| is_diskbased | character(1) | Whether this step of the query was performed as a
disk-based operation: true (t) or false
(f). |
| workmem | bigint | Number of bytes of working memory assigned to the step. |
Sample queries
The following query shows which save steps in the most recent query were performed on each slice.
select query, slice, segment, step, tasknum, rows, tbl from stl_save where query = pg_last_query_id(); query | slice | segment | step | tasknum | rows | tbl -------+-------+---------+------+---------+------+----- 52236 | 3 | 0 | 2 | 21 | 0 | 239 52236 | 2 | 0 | 2 | 20 | 0 | 239 52236 | 2 | 2 | 2 | 20 | 0 | 239 52236 | 3 | 2 | 2 | 21 | 0 | 239 52236 | 1 | 0 | 2 | 21 | 0 | 239 52236 | 0 | 0 | 2 | 20 | 0 | 239 52236 | 0 | 2 | 2 | 20 | 0 | 239 52236 | 1 | 2 | 2 | 21 | 0 | 239 (8 rows)
