If you are performing a data load with a large external file as input, you can verify that the process is continuing by getting progress information during the load. Progress information can be obtained from the pgx_stat_progress_loader view. This view displays the sum of the progress information of the back-end process and the number of parallel worker processes. Search the pgx_stat_progress_loader view, for example, with a SELECT statement, to locate the appropriate row. After running the pgx_loader command, look in the pg_stat_activity view and locate a row in the pgx_stat_progress_loader view with the PID obtained.
Example
See the pg_stat_activity view. (9311 for back-end processes, 9312, 9313, 9314 for worker processes)
postgres=# select pid, application_name, backend_type from pg_stat_activity pid | application_name | backend_type -----+------------------+------------------------------ 6216 | | autovacuum launcher 6218 | | logical replication launcher 6271 | psql | client backend 9311 | pgx_loader | client backend 9312 | | parallel loader for PID 9311 9313 | | parallel loader for PID 9311 9314 | | parallel loader for PID 9311 6214 | | background writer 6213 | | checkpointer 6215 | | walwriter
Check the information in the pgx_stat_progress_loader view.
postgres=# SELECT * FROM pgx_stat_progress_loader pid | datid | datname | relid | command | type | bytes_processed | bytes_total | tuples_processed | tuples_excluded -----+-------+---------+-------+----------+------+-----------------+-------------+------------------+---------------- 9311 | 222 | testdb | 333 |COPY FROM | FILE | 192000 | 450000 | 189000 | 3000
Refer to "D.7 pgx_stat_progress_loader" for information on the pgx_stat_progress_loader view.
Note
When you run the pgx_loader command, the PostgreSQL pg_stat_progress_copy view prints the progress of the back-end process and the number of parallel worker processes on each line. The backend process progress information tuples_processed, tuples_excluded is 0. Also, bytes_processed and bytes_total for worker processes are 0.
postgres=# SELECT * FROM pg_stat_progress_copy pid | datid | datname | relid | command | type | bytes_processed | bytes_total | tuples_processed | tuples_excluded -----+-------+---------+-------+----------+------+-----------------+-------------+------------------+---------------- 9311 | 222 | testdb | 333 |COPY FROM | FILE | 192000 | 450000 | 0 | 0 9312 | 222 | testdb | 333 |COPY FROM | FILE | 0 | 0 | 63000 | 1000 9313 | 222 | testdb | 333 |COPY FROM | FILE | 0 | 0 | 63000 | 1000 9314 | 222 | testdb | 333 |COPY FROM | FILE | 0 | 0 | 63000 | 1000
Refer to "pg_stat_progress_copy View" in the PostgreSQL Documentation for information on the pg_stat_progress_copy view.
