compute_query_id

[kvaikla]

Hi,
Does PostgreSQL JDBC Driver somehow disables or overrides this postgres feature?
If user comes to database using this driver, query_id in pg_stat_activity is not present. At instance level compute_query_id is on.

Fore example, using a query like this:

select application_name,  DATE_TRUNC('second', backend_start) backend_start,  DATE_TRUNC('second', query_start) query_start, DATE_TRUNC('second', now()) now,query_id, left(query, 6) query from pg_stat_activity where xact_start is not NULL;

Outputs are:

    application_name    |     backend_start      |      query_start       |          now           |      query_id       | query  
------------------------+------------------------+------------------------+------------------------+---------------------+--------
 PostgreSQL JDBC Driver | 2023-05-12 15:16:53+03 | 2023-05-12 15:22:14+03 | 2023-05-12 15:22:14+03 |                     | select
 psql                   | 2023-05-12 12:17:48+03 | 2023-05-12 15:22:14+03 | 2023-05-12 15:22:14+03 | 3277233299598306329 | select
(2 rows)

 application_name |     backend_start      |      query_start       |          now           |      query_id       | query  
------------------+------------------------+------------------------+------------------------+---------------------+--------
 pgwatch2         | 2023-05-12 15:24:30+03 | 2023-05-12 15:24:30+03 | 2023-05-12 15:24:31+03 | 2551699808678778212 |       +
                  |                        |                        |                        |                     |       +
                  |                        |                        |                        |                     | SELE
 psql             | 2023-05-12 12:17:48+03 | 2023-05-12 15:24:31+03 | 2023-05-12 15:24:31+03 | 3277233299598306329 | select
(2 rows)

    application_name    |     backend_start      |      query_start       |          now           |      query_id       | query  
------------------------+------------------------+------------------------+------------------------+---------------------+--------
 PostgreSQL JDBC Driver | 2023-05-12 15:16:59+03 | 2023-05-12 15:39:59+03 | 2023-05-12 15:39:59+03 |                     | select
 PostgreSQL JDBC Driver | 2023-05-12 15:16:46+03 | 2023-05-12 15:39:59+03 | 2023-05-12 15:39:59+03 |                     | select
 psql                   | 2023-05-12 12:17:48+03 | 2023-05-12 15:39:59+03 | 2023-05-12 15:39:59+03 | 3277233299598306329 | select
(3 rows)

It means, if PostgreSQL JDBC Driver, no query_id.
Is it expected behavior or related to driver version?

br
Kaido

[davecramer]

The driver has no way to disable the feature, but I am curious how this is happening.

One thing to note is that the driver uses extended query protocol so the queries are not identical.