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 information as 64-bit version so that the information of specified transaction easily can be identified and picked up by transaction ID. Otherwise it's not easy to distinguish transactions with the same 32-bit XID but different epoch, only by 32-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 to xid8. But this idea looks overkill to me, and it may break the existing applications accessing pg_locks etc. So IMO it's better to just provide the convertion function. Regards, -- Fujii Masao Advanced Computing Technology Center Research and Development Headquarters NTT DATA CORPORATION
