Hello all and Heikki personally

Thank you for your answer

I have some new points:

Понедельник, 21 января 2013, 10:08 +02:00 от Heikki Linnakangas 
>On 21.01.2013 09:14, Миша Тюрин wrote:
>>    Is there any reason why pg_basebackup has limitation in an online backup 
>> from the standby: "The backup history file is not created in the database 
>> cluster backed up." ?
>WAL archiving isn't active in a standby, so even if it created a backup 
>history file, it wouldn't go anywhere. Also, the way the backup history 
>files are named, if you take a backup on the master at the same time (or 
>another backup at the same time in the standby), you would end up with 
>multiple backup history files with the same name.
>>    So i can't get last xlog file needed to restore :(
>Good point. That was an oversight in the patch that allowed base backups 
>from a standby.
>>    Also maybe i can use something like ( pg_last_xlog_replay_location() + 1 
>> ) after pg_basebackup finished.
>Yeah, that should work.
>>    Does anybody know true way to getting last xlog file in case of applying 
>> pg_basebackup to standby?
>>    How pg_basebackup gets last xlog file in case of standby and -x option?
>The server returns the begin and end WAL locations to pg_basebackup, 
>pg_basebackup just doesn't normally print them out to the user. In 
>verbose mode, it does actually print them out, but only with -x, so that 
>doesn't help you either. If you can compile from source, you could 
>modify pg_basebackup.c to print the locations without -x and --verbose, 
>search lines that print out "transaction log start point / end position".

1) we can get last xlog by using control data's "Minimum recovery ending 

>As a workaround, without modifying the source, you can do this after 
>pg_basebackup has finished, to get the first WAL file you need:
>$ pg_controldata backupdir | grep "REDO WAL file"
>Latest checkpoint's REDO WAL file:    000000030000000000000009

and I would like to correct your suggestion about first wal file
2.1)  we should use backup_label to determine first needed wal
2.2)  and we must not use redo from checkpoint. because there are might be more 
than one checkpoint during base_backup

>And as you suggested, pg_last_xlog_replay_location() for the last WAL 
>file you need.
>- Heikki
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- Misha

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