Re: WAL segments (names) not in a sequence

> I think these are the WAL files that were preallocated by WAL
> recycling but have not
> been used yet.
>
>> # WAL after wal_level changed from 'minimal' to 'hot_standby'
>>
>> -rw------- 1 postgres postgres 16777216 May 21 12:27 000000010000000E0000007B
>> -rw------- 1 postgres postgres 16777216 May 21 12:35 000000010000000E0000007C
>> -rw------- 1 postgres postgres 276 May 21 12:35
>> 000000010000000E0000007C.00000020.backup
>> -rw------- 1 postgres postgres 16777216 May 21 14:53 000000010000000E0000007D
>> -rw------- 1 postgres postgres 16777216 May 21 14:53 000000010000000E0000007E
>> -rw------- 1 postgres postgres 16777216 May 21 14:53 000000010000000E0000007F
>> -rw------- 1 postgres postgres 16777216 May 21 14:53 000000010000000E00000080
>
> These are the WAL files that you now used. So I don't think that WAL
> file sequence rewound
> in this case.
>

Can pre-allocation go that further? for example, assuming
000000010000000E00000080 is currently being used, then is it possible
that a segment named/numbered 00000001000000100000007E (which does
exist in his pg_xlog as he reported in pgsql-admin thread) is
pre-allocated already?

I think we could ask the user the latest value of "select
pg_xlogfile_name(pg_xlog_current_location())".

--
Amit Langote