Re: Faster StrNCpy - Mailing list pgsql-hackers

From Strong, David
Subject Re: Faster StrNCpy
Date
Msg-id B6419AF36AC8524082E1BC17DA2506E802579E2E@USMV-EXCH2.na.uis.unisys.com
Whole thread Raw
In response to Re: Faster StrNCpy  ("Strong, David" <david.strong@unisys.com>)
List pgsql-hackers
Tom,
Yes, the clients are using the V3 protocol and prepared statements.
David

________________________________

From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
Sent: Mon 10/2/2006 2:09 PM
To: Strong, David
Cc: pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] Faster StrNCpy



"Strong, David" <david.strong@unisys.com> writes:
> Obviously, different copy mechanisms suit different data sizes. So, I
> added a little debug to the strlcpy () function that was added to
> Postgres the other day. I ran a test against Postgres for ~15 minutes
> that used 2 client backends and the BG writer - 8330804 calls to
> strlcpy () were generated by the test.

> Out of the 8330804 calls, 6226616 calls used a maximum copy size of
> 2213 bytes e.g. strlcpy (dest, src, 2213) and 2104074 calls used a
> maximum copy size of 64 bytes.

> I know the 2213 size calls come from the set_ps_display () function. I
> don't know where the 64 size calls come from, yet.

Prepared-statement and portal hashtable lookups, likely.  Were your
clients using V3 extended query protocol?
                       regards, tom lane




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