Re: Flush to Disk - Mailing list pgsql-hackers

From Manfred Spraul
Subject Re: Flush to Disk
Date
Msg-id 40671797.2010905@colorfullife.com
Whole thread Raw
In response to Flush to Disk  (Diego Montenegro <diego.montenegro@yale.edu>)
List pgsql-hackers
Diego Montenegro wrote:

>Hello all,
>
>Can anyone point me to where in the code does Postgres Flush all the
>Data to disk???
>When XLogFlush is called, it only flushes the XLOG to disk, right? Does
>the entire Data get flushed at the same time as the Log? 
>  
>
in src/backend/storage/smgr/md.c, mdsync(): During a checkpoint, the 
whole system cache is synced to the disk.
Note that checkpoints should be rare - I think every few minutes. The 
xlog contains enough data to recover a transaction after a system crash, 
therefore only the xlog is forced to the disk during transaction commit.

--   Manfred



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