STL_SORT
Displays sort execution steps for queries, such as steps that use ORDER BY processing.
This table 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.
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 executed. |
| starttime | timestamp | Time in UTC that the query started executing, 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 executing, 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 execute 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 | Table ID. |
| is_diskbased | character(1) | If true (t), the query was executed as a disk-based operation. If false (f), the query was executed in memory. |
| workmem | bigint | Total number of bytes in working memory that were assigned to the step. |
| checksum | bigint | This information is for internal use only. |
Sample Queries
The following example returns sort results for slice 0 and segment 1.
select query, bytes, tbl, is_diskbased, workmem from stl_sort where slice=0 and segment=1;
query | bytes | tbl | is_diskbased | workmem -------+---------+-----+--------------+----------- 567 | 3126968 | 241 | f | 383385600 604 | 5292 | 242 | f | 383385600 675 | 104776 | 251 | f | 383385600 525 | 3126968 | 251 | f | 383385600 585 | 5068 | 241 | f | 383385600 630 | 204808 | 266 | f | 383385600 704 | 0 | 242 | f | 0 669 | 4606416 | 241 | f | 383385600 696 | 104776 | 241 | f | 383385600 651 | 4606416 | 254 | f | 383385600 632 | 0 | 256 | f | 0 599 | 396 | 241 | f | 383385600 86397 | 0 | 242 | f | 0 621 | 5292 | 241 | f | 383385600 86325 | 0 | 242 | f | 0 572 | 5068 | 242 | f | 383385600 645 | 204808 | 241 | f | 383385600 590 | 396 | 242 | f | 383385600 (18 rows)
