Hi,
When periodically collecting and accumulating statistics or status information like pg_locks, pg_stat_activity,
pg_prepared_xacts,etc for future troubleshooting or some reasons, I'd like to store a transaction ID of such
informationas 64-bit version so that the information of specified transaction easily can be identified and picked up by
transactionID. Otherwise it's not easy to distinguish transactions with the same 32-bit XID but different epoch, only
by32-bit XID.
But since pg_locks or pg_stat_activity etc returns 32-bit XID, we could not store it as 64-bit version. To improve this
situation,I'd like to propose to add new function that converts the given 32-bit XID (i.e., xid data type) to 64-bit
one(xid8 data type). If we do this, for example we can easily get 64-bit XID from pg_stat_activity by "SELECT
convert_xid_to_xid8(backend_xid)FROM pg_stat_activity", if necessary. Thought?
As another approach, we can change the data type of pg_stat_activity.backend_xid or pg_locks.transaction, etc from xid
toxid8. But this idea looks overkill to me, and it may break the existing applications accessing pg_locks etc. So IMO
it'sbetter to just provide the convertion function.
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION