Обсуждение: pg_xlogfile_name for PostgreSQL 8.0

girish R G peetle wrote:
> On PostgreSQL 8.0, I need to convert output of pg_start_backup / pg_stop_backup to transaction log
> file name. In the the latest versions we have pg_xlogfile_name function to do this, but 8.0 there is
> not function to achieve this.
> 
> Is it possible to export pg_xlogfile_name function from the latest versions(8.2+) and import it to
> PostgreSQL 8.0 server ?
> 
> I couldn't find any information regrading getting a dump of system function in PostgreSQL
> documentation.

You cannot dump/restore this function into 8.0, it needs server side C code.

The best you can probably do is to figure out part of the name yourself,
like WAL location '1/80000A8' corresponds to *0000000100000008 (with a wildcard,
because we do not know the time line).
That's maybe good enough to narrow down which WAL file to archive.

Yours,
Laurenz Albe

girish R G peetle wrote:
> backup_label (after execting pg_start_backup)  will have the start transaction log file information, I
> can this use this file to extract the current time line ID.
> Also I guess the time line ID will be changed only when server is recovered. So, I can safely use the
> same Time Line ID extracted from backup_label to formulate the transaction log file from the output of
> pg_stop_backup also.

That should work.

Yours,
Laurenz Albe