SYS_UNLOAD_HISTORY - Amazon Redshift
Table columnsSample queries

Amazon Redshift will no longer support the creation of new Python UDFs starting November 1, 2025. If you would like to use Python UDFs, create the UDFs prior to that date. Existing Python UDFs will continue to function as normal. For more information, see the blog post .

SYS_UNLOAD_HISTORY

Use SYS_UNLOAD_HISTORY to view details of UNLOAD commands. Each row represents a UNLOAD command with accumulated statistics for some of the fields. It contains both running and finished UNLOAD commands.

SYS_UNLOAD_HISTORY 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
user_id integer The identifier of the user who submitted the unload.
query_id bigint The query identifier of the UNLOAD command.
transaction_id bigint The transaction identifier.
session_id integer The process identifier of the process running the unload.
database_name text The name of the database the user was connected to when the operation was issued.
status text The status of the UNLOAD command. Valid values include: running, completed, aborted, and unknown.
start_time timestamp The time when the unload began.
end_time timestamp The time when the unload completed.
duration bigint The amount of time (microseconds) spent in the UNLOAD command.
file_format text The file format of the output files.
compression_type text The compression type.
unloaded_location text The Amazon S3 location of unloaded files.
unloaded_rows bigint The number of rows.
unloaded_files_count bigint The file count of the output file.
unloaded_files_size bigint The file size of the output file.
error_message text The error message of the UNLOAD command.

Sample queries

The following query shows the unloaded query details, including format, rows, and file count of unload command.

SELECT query_id,
       file_format,
       start_time,
       duration,
       unloaded_rows,
       unloaded_files_count
FROM sys_unload_history
ORDER BY query_id,
file_format limit 100;

Sample output.

 query_id | file_format |         start_time         | duration | unloaded_rows | unloaded_files_count
----------+-------------+----------------------------+----------+---------------+----------------------
   527067 | Text        | 2022-02-09 05:18:35.844452 |  5932478 |            10 |                    1