We are seeing big problems
when issuing disk writes using 10G (both 10.1 and 10.2). Reads are not an
issue
Very difficult to track
down the exact combination but so far it looks as if it is a combination of 10G
and local disk mounted using UFS .
V440 Solaris servers could
also come into the combination because that is what I have done a lot of the
testing on as that is what is available. I have now tested on around 10-12
servers with consistent findings.
The test is very simple
and quick to do. Searching Metalink and WebIV does not give any clues. I am
about to log a tar but I know I will require all sorts of Unix information which
is quite long-winded for me to get so any help would be
appreciated.
The
test
CREATE
TABLE test( a number, b CHAR(2000) )tablespace xxxx
;
Set
timing on
BEGIN
FOR r IN 1..50000 LOOP
INSERT INTO test (a,b) VALUES (r,
‘test’);
COMMIT;
END
END
On
SAN disk and 9i on local UFS mounted disk I am seeing response times from 0:15
to 0:30 seconds
On
10G on San I see the same
On
10G using local UFS disk the time various from 7:00 to 9:00 minutes and is very
repeatable.
I
have tried around 10 servers now and the results are
consistent.
Whilst
we have quite a few 10G installations, not many are on local disk and the
majority are on Sun 440 (2.9 OS) so my results may indicate a UFS problem when
it could be an OS one (or an Oracle one of course). OS writes to disk are stable
at twice as fast on San as local disk and the fact that 90i does not show a
problem seems to take away the OS part out of the equation. But nothing is
certain yet.
PS
the waits are all IO related - log buffer , log file sync
etc
Thanks
for any help
John