Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the [ blog post ](https://aws.amazon.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). # STL\_AGGR Analyzes aggregate execution steps for queries. These steps occur during execution of aggregate functions and GROUP BY clauses. STL\_AGGR 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](cm_chap_system-tables.md#c_visibility-of-data). **Note** STL\_AGGR 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](SYS_QUERY_DETAIL.md). 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. | | slots | integer | Number of hash buckets. | | occupied | integer | Number of slots that contain records. | | maxlength | integer | Size of the largest slot. | | tbl | integer | Table ID. | | is\_diskbased | character(1) | If true (t), the query was run as a disk-based operation. If false (f), the query was run in memory. | | workmem | bigint | Number of bytes of working memory assigned to the step. | | type | character(6) | The type of step. Valid values are: [See the AWS documentation website for more details](http://docs.aws.amazon.com/redshift/latest/dg/r_STL_AGGR.html) | | resizes | integer | This information is for internal use only. | | flushable | integer | This information is for internal use only. | ## Sample queries Returns information about aggregate execution steps for SLICE 1 and TBL 239. ``` select query, segment, bytes, slots, occupied, maxlength, is_diskbased, workmem, type from stl_aggr where slice=1 and tbl=239 order by rows limit 10; ``` ``` query | segment | bytes | slots | occupied | maxlength | is_diskbased | workmem | type -------+---------+-------+---------+----------+-----------+--------------+-----------+-------- 562 | 1 | 0 | 4194304 | 0 | 0 | f | 383385600 | HASHED 616 | 1 | 0 | 4194304 | 0 | 0 | f | 383385600 | HASHED 546 | 1 | 0 | 4194304 | 0 | 0 | f | 383385600 | HASHED 547 | 0 | 8 | 0 | 0 | 0 | f | 0 | PLAIN 685 | 1 | 32 | 4194304 | 1 | 0 | f | 383385600 | HASHED 652 | 0 | 8 | 0 | 0 | 0 | f | 0 | PLAIN 680 | 0 | 8 | 0 | 0 | 0 | f | 0 | PLAIN 658 | 0 | 8 | 0 | 0 | 0 | f | 0 | PLAIN 686 | 0 | 8 | 0 | 0 | 0 | f | 0 | PLAIN 695 | 1 | 32 | 4194304 | 1 | 0 | f | 383385600 | HASHED (10 rows) ```