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Thread: buffer manager

buffer manager

From
"ravi chotalia"
Date:
hi
i'm working on typical problem of comparing buffer manager's policies
(MRU/LRU/FIFO) and working on postgresql 8-03 . I read old versiona and beta
version and found 8-03 uses LRU 2q and the newer beta version is using
simple LRU but this time global buffer lock is used removing vacum process
in freelist. since i'm working on 8-03 and want to change my code as less as
possible , is there any version where simple LRU is used with 8-0-3's vacum
and BufferStrategyCDB stuff.
regards
ravi

_________________________________________________________________
1000s of Sexy Singles online now at Lavalife http://lavalife.com.au

Re: buffer manager

From
Alvaro Herrera
Date:
On Tue, Sep 13, 2005 at 04:38:27AM +0000, ravi chotalia wrote:
> hi
> i'm working on typical problem of comparing buffer manager's policies
> (MRU/LRU/FIFO) and working on postgresql 8-03 . I read old versiona and
> beta version and found 8-03 uses LRU 2q and the newer beta version is using
> simple LRU but this time global buffer lock is used removing vacum process
> in freelist. since i'm working on 8-03 and want to change my code as less
> as possible , is there any version where simple LRU is used with 8-0-3's
> vacum and BufferStrategyCDB stuff.

IIRC Neil Conway posted a patch to make 8.0.2 use LRU instead of ARC,
when the whole patent issue arised.  You could search that in the
archives.  OTOH, the current devel code uses an approach completely
different to both.

--
Alvaro Herrera -- Valdivia, Chile         Architect, www.EnterpriseDB.com
"¿Que diferencia tiene para los muertos, los huérfanos, y aquellos que han
perdido su hogar, si la loca destrucción ha sido realizada bajo el nombre
del totalitarismo o del santo nombre de la libertad y la democracia?" (Gandhi)

Re: buffer manager

From
Tom Lane
Date:
"ravi chotalia" <bse_2004@hotmail.com> writes:
> is there any version where simple LRU is used with 8-0-3's vacum
> and BufferStrategyCDB stuff.

No.  There never will be either, because that code is completely gone
in CVS tip.

[ This seems a tad off-topic for pgsql-general... ]

            regards, tom lane

Re: buffer manager

From
Neil Conway
Date:
Alvaro Herrera wrote:
> IIRC Neil Conway posted a patch to make 8.0.2 use LRU instead of ARC,
> when the whole patent issue arised.

http://archives.postgresql.org/pgsql-patches/2005-01/msg00253.php

-Neil