Re: Db file scattered reads vs. direct path reads
Date: Fri, 22 Feb 2008 12:21:27 -0500 (EST)
38ms (38471 microseconds) sounds like a read from physical spindles. The 5 microseconds in the second instance is extremely fast so it likely to be a cache hit in some layer of your storage system.
Is it possible to perform a manual cache flush for your new disk system and retry the direct path test?
> ----- Original Message -----
> From: "Josh Collier" <Josh.Collier_at_banfield.net>
> To: <oracle-l_at_freelists.org>
> Sent: Wednesday, February 20, 2008 8:20 PM
> Subject: Db file scattered reads vs. direct path reads
> WAIT #1: nam='db file scattered read' ela= 38471 file#=777 block#=238789
> blocks=64 obj#=2805234 tim=359927798919
> WAIT #1: nam='direct path read' ela= 5 file number=777 first dba=238789
> cnt=64 obj#=2805234 tim=343398354853