Subject: Re: WAL restoration is not happening completely
To: rajan <vgmonnet@gmail.com>, pgsql-admin@postgresql.org
References: <1479116970057-5930204.post@n3.nabble.com>
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 <20161114175509.3wgvxos44hxxz26i@alap3.anarazel.de>
 <1479467832483-5930928.post@n3.nabble.com>
From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Organization: 2ndQuadrant
Message-ID: <c9a040c0-9f60-5ac3-3b3e-bf2d3196ca9d@2ndquadrant.com>
Date: Fri, 18 Nov 2016 12:19:25 -0500
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On 11/18/16 6:17 AM, rajan wrote:
> One thing I missed to update is that the Source(master) machine I was
> running is switched off and on everyday. It may have caused any disruption
> in the WAL files?

Well, the point of the WAL is to preserve data integrity in case of
crashes.  So, no, that should normally not cause problems.

> And one more question, The WAL files are created as 16MB segments, that is
> obvious. But I do not know when the file is completely written. Is it like,
> a file is created and then written till 16MB or 16MB data segment is
> directly written at once.

It is written in smaller chunks and then archived or rotated when the 16
MB are full.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


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