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doc/TODO.detail/performance

@@ -345,7 +345,7 @@ From owner-pgsql-hackers@hub.org Tue Oct 19 10:31:10 1999
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@@ -695,3 +695,47 @@ LRU-2 idea and am not pursuing it.
 			regards, tom lane
 
 
+From pgsql-hackers-owner+M3455@postgresql.org Fri Jan 19 13:18:12 2001
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+From: "Mikheev, Vadim" <vmikheev@SECTORBASE.COM>
+To: "'Tom Lane'" <tgl@sss.pgh.pa.us>, Bruce Momjian <pgman@candle.pha.pa.us>
+Cc: pgsql-hackers@postgresql.org
+Subject: RE: [HACKERS] Possible performance improvement: buffer replacemen
+	t policy 
+Date: Fri, 19 Jan 2001 10:07:27 -0800
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+Status: OR
+
+> > Tom, did we ever test this?  I think we did and found that 
+> > it was the same or worse, right?
+> 
+> I tried it and didn't see any noticeable improvement on the particular
+> test case I was using, so I got discouraged and didn't pursue the idea
+> further.  I'd like to come back to it someday, though.
+
+I don't know how much useful could be LRU-2 but with WAL we should try
+to reuse undirty free buffers first, not dirty ones, just to postpone
+writes as long as we can. (BTW, this is what Oracle does.)
+So, we probably should put new free dirty buffer just before first
+undirty one in LRU.
+
+Vadim
+