Re: WIP patch for latestCompletedXid method of computing snapshot xmax - Mailing list pgsql-hackers

From Gregory Stark
Subject Re: WIP patch for latestCompletedXid method of computing snapshot xmax
Date
Msg-id 87r6l8x2e6.fsf@oxford.xeocode.com
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In response to Re: WIP patch for latestCompletedXid method of computing snapshot xmax  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
"Tom Lane" <tgl@sss.pgh.pa.us> writes:

> My desktop machine has a single consumer-grade IDE drive, and even with
> fsync off and synchronous_commit off, it can barely make 190 tps sustained
> pgbench throughput --- it's just disk write bound all the time. On a run
> with 8 clients, 10000 transactions per client, DB scale factor 25, I get
> this distribution of transaction times from CVS HEAD:

Wouldn't you expect to see more of an effect on cpu-bound environments? Is
there any i/o going on while these locks are being held? I suppose there's a
WAL commit record that has to be synced?

Have you tried with a smaller scale factor?

--  Gregory Stark EnterpriseDB          http://www.enterprisedb.com


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