Temp tables and LRU-K caching - Mailing list pgsql-hackers

From Mike Mascari
Subject Temp tables and LRU-K caching
Date
Msg-id 3D8F39DA.4070802@mascari.com
Whole thread Raw
Responses Re: Temp tables and LRU-K caching  (Tom Lane <tgl@sss.pgh.pa.us>)
Re: Temp tables and LRU-K caching  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-hackers
Hello.

I'm just curious as to the 7.3 status of a couple of things:

1. Back in Feb. I wrote (in regards to Oracle behavior):

"Unlike normal queries where blocks are added to the MRU end of 
an LRU list, full table scans add the blocks to the LRU end of 
the LRU list. I was wondering, in the light of the discussion of 
using LRU-K, if PostgreSQL does, or if anyone has tried, this 
technique?"

Bruce wrote:

"Yes, someone from India has a project to test LRU-K and MRU for 
large table scans and report back the results.  He will 
implement whichever is best."

Did this make it into 7.3?

2. Gavin Sherry had worked up a patch so that temporary 
relations could be dropped automatically upon transaction 
commit. Did any of those patches it make it? I notice that 
whenever I create a temporary table in a transaction, my HD 
light blinks. Is this a forced fsync() causes by the fact that 
the SQL standard defines temporary relations as surviving across 
transactions? If so, I'd bet those of us who use 
transaction-local temporary tables could get few drops more of 
performance from an ON COMMIT drop patch w/o fsync.

Any thoughts?

Mike Mascari
mascarm@mascari.com





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