On 5/18/25 12:20, Jevon Cowell wrote:
Hi Folks!
Let me know if there's a better mailing list to ask this in.
I have a statistics collector that collects data from various postgres
statistics tables, pg_stat_statements being one of them. This is done on
an entire fleet of Postgres databases. From the collected data we record
the timestamp of each collection in the query itself as extract(epoch
from now()) as ts. What I'm seeing is that for the same query
/and/ query id, there are two rows with different statistics data /at
the same time/. For example one row can have 2 calls while another can
have 4. Anyone else run into this or have any idea why this can occur?
From here:
https://www.postgresql.org/docs/current/pgstatstatements.html
queryid bigint
Hash code to identify identical normalized queries.
query text
Text of a representative statement
From here:
https://www.postgresql.org/docs/current/functions-datetime.html#FUNCTIONS-DATETIME-CURRENT
"now() is a traditional PostgreSQL equivalent to transaction_timestamp()"
and
"transaction_timestamp() is equivalent to CURRENT_TIMESTAMP, but is
named to clearly reflect what it returns."
Therefore now() is pinned to the time the transaction started.
Consequently it is conceivable that the queries actually ran at
different times but got stamped with an identical timestamp via
extract(epoch from now()) as ts.
Regards,
Jevon Cowell
--
Adrian Klaver
adrian.kla...@aklaver.com
