Re: Flashback log file sync

From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Sat, 12 May 2012 19:03:30 +0000 (UTC)
Message-ID: <pan.2012.05.12.19.03.30_at_gmail.com>

On Sat, 12 May 2012 19:49:36 +0100, Jonathan Lewis wrote:

> Did you check the session stats to see what your reads were ?

I turned on 10046 tracing. Reads were from the TEST_LOB tablespace, the LOB segmentL

=126792 block cnt=4 obj#=-1 tim=1336849142292618

WAIT #140145345192712: nam='direct path read' ela= 280 file number=7 
first dba=127180 block cnt=4 obj#=-1 tim=1336849142302190
WAIT #140145345192712: nam='direct path read' ela= 359 file number=7 
first dba=126352 block cnt=4 obj#=-1 tim=1336849142303526
WAIT #140145345192712: nam='direct path read' ela= 136 file number=7 
first dba=126416 block cnt=4 obj#=-1 tim=1336849142341101
WAIT #140145345192712: nam='direct path read' ela= 38497 file number=7 
first dba=126480 block cnt=4 obj#=-1 tim=1336849142379976
WAIT #140145345192712: nam='direct path read' ela= 122 file number=7 
first dba=126612 block cnt=4 obj#=0 tim=1336849142445429
WAIT #140145345192712: nam='direct path read' ela= 337 file number=7 
first dba=126488 block cnt=4 obj#=0 tim=1336849142450894
WAIT #140145345192712: nam='direct path read' ela= 4656 file number=7 
first dba=126552 block cnt=4 obj#=0 tim=1336849142478622
WAIT #140145345192712: nam='direct path read' ela= 2062 file number=7 
first dba=126616 block cnt=4 obj#=0 tim=1336849142529709
WAIT #140145345192712: nam='direct path read' ela= 2366 file number=7 
first dba=126680 block cnt=4 obj#=0 tim=1336849142532207
WAIT #140145345192712: nam='direct path read' ela= 239 file number=7 
first dba=126496 block cnt=4 obj#=-1 tim=1336849142636995
WAIT #140145345192712: nam='direct path read' ela= 260 file number=7 
first dba=126624 block cnt=4 obj#=-1 tim=1336849142637611

I increased the chunk size to 32K and got reads by 4 blocks, which means that Oracle is reading a chunk into PGA.

-- 
http://mgogala.byethost5.com

Received on Sat May 12 2012 - 14:03:30 CDT