RE: DBWR slaves in NT???

From: Jesse, Rich <Rich.Jesse_at_qtiworld.com>
Date: Thu, 01 Mar 2001 11:41:20 -0800
Message-ID: <F001.002C1354.20010301113043@fatcity.com>

Actually, that message is invalid for Oracle8 DBs. From what I can gather, the DB_FILES init.ora parameter only
potentially affected DBWR performance in Oracle7. In Oracle8, it ain't true.

Remember, the DBWRs write dirty buffers (data in memory that has been modified from it's counterpart in a datafile) from the buffer cache (memory) to the datafiles (disk). In O7, the DBWR I/O clump size, or how many dirty blocks could be written at once (also sometimes referred to as the DBWR's "internal write batch size"), was calculated as:

DB_FILE_SIMULTANEOUS_WRITES*DB_FILES/2. In O8, the DBWR I/O clump size is static, and is different from platform to platform. Thus, for Oracle8, the advise to change DB_FILES is bogus.

HTH!

Rich Jesse                          System/Database Administrator
Rich.Jesse_at_qtiworld.com             Quad/Tech International, Sussex, WI USA

Disclaimer: After taking the Oracle8 Perf Tuning class, I think I know more than I do. Don't blame me for your (in)actions based on my opinion!

-----Original Message-----
Sent: Thursday, March 01, 2001 12:27
To: Multiple recipients of list ORACLE-L

not a dbwriter problem.
on a "single-disk wonder", your best
bet is to DUMP all indexes on loadable
tables, then load your data, then rebuild the indexes.
of course, that might take just as long. any possiblity of getting more disk?
like, several? a raid controller?
mit gluck!

-----Original Message-----
Sent: Thursday, March 01, 2001 11:26 AM To: Multiple recipients of list ORACLE-L

Hi Friends
I have toad tool for my NT database
DBWR Average Scan Depth 1024 **Number of DB_Files too high?? I got doubt due to from v$waitstat I got data block waits some time 8000 and

some times higher number. How can I increase the DBWR slaves on NT?? although I set in development box, How can I see as background process really working for me??
I have my datafile and indexes same on E disk drive, My hit ratios are okay,

My import is killing me.
Any help appreciated.
Thanks
Raghu.

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Author: Raghu Kota
INET: raghukota_at_hotmail.com

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Author: Jesse, Rich
INET: Rich.Jesse_at_qtiworld.com

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