Re: Online base backup from the hot-standby - Mailing list pgsql-hackers

From Jun Ishiduka
Subject Re: Online base backup from the hot-standby
Date
Msg-id 201108170900.p7H90CX9018760@ccmds32.silk.ntts.co.jp
Whole thread Raw
In response to Re: Online base backup from the hot-standby  (Steve Singer <ssinger_pg@sympatico.ca>)
Responses Re: Online base backup from the hot-standby
List pgsql-hackers
> Is there any way to tell from the WAL segments if they contain the full
> page data? If so could you verify this on the second slave when it is
> brought up? Or can you track this on the first slave and produce an
> error in either pg_start_backup or pg_stop_backup()

Sure.
I will make a patch with the way to tell from the WAL segments if they 
contain the full page data.


> I see in xlog.h XLR_BKP_REMOVABLE, the comment above it says that this
> flag is used to indicate that the archiver can compress the full page
> blocks to non-full page blocks. I am not familiar with where in the code
> this actually happens but will this cause issues if the first standby is
> processing WAL files from the archive?

I confirmed the flag in xlog.c, so I seemed to only insert it in 
XLogInsert(). I consider whether it is available.


--------------------------------------------
Jun Ishizuka
NTT Software Corporation
TEL:045-317-7018
E-Mail: ishizuka.jun@po.ntts.co.jp
--------------------------------------------




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