SVCS_UNLOAD_LOG

Use the SVCS_UNLOAD_LOG to get details of UNLOAD operations.

SVCS_UNLOAD_LOG records one row for each file created by an UNLOAD statement. For example, if an UNLOAD creates 12 files, SVCS_UNLOAD_LOG contains 12 corresponding rows. This view is derived from the STL_UNLOAD_LOG system table but doesn't show slice-level for queries run on a concurrency scaling cluster.

Note

System views with the prefix SVCS provide details about queries on both the main and concurrency scaling clusters. The views are similar to the tables with the prefix STL except that the STL tables provide information only for queries run on the main cluster.

SVCS_UNLOAD_LOG 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	The ID of the user who generated the entry.
query	integer	The query ID.
pid	integer	The process ID associated with the query statement.
path	character(1280)	The complete Amazon S3 object path for the file.
start_time	timestamp	The start time for the UNLOAD operation.
end_time	timestamp	The end time for the UNLOAD operation.
line_count	bigint	The number of lines (rows) unloaded to the file.
transfer_size	bigint	The number of bytes transferred.
file_format	character(10)	The format of unloaded file.

Sample query

To get a list of the files that were written to Amazon S3 by an UNLOAD command, you can call an Amazon S3 list operation after the UNLOAD completes; however, depending on how quickly you issue the call, the list might be incomplete because an Amazon S3 list operation is eventually consistent. To get a complete, authoritative list immediately, query SVCS_UNLOAD_LOG.

The following query returns the path name for files that were created by an UNLOAD for the last query completed:

select query, substring(path,0,40) as path
from svcs_unload_log
where query = pg_last_query_id()
order by path;

This command returns the following sample output:

 
 query |             path
 ------+---------------------------------------------
  2320 | s3://amzn-s3-demo-bucket/venue0000_part_00
  2320 | s3://amzn-s3-demo-bucket/venue0001_part_00
  2320 | s3://amzn-s3-demo-bucket/venue0002_part_00
  2320 | s3://amzn-s3-demo-bucket/venue0003_part_00
(4 rows)