Re: How many databases do you support?

Hi,

In my previous job, there were 30 database servers (10 production, 10 stand by and 10 test) on HP-UX with Oracle 7 and Informix 7. There were 2 DBA's and 4 UNIX SA's.

Currently, I'm in a group of 5 taking care of a dozen of Oracle's 7-8i (NT and Digital UNIX) and about 1000 Sybase ASE11 servers (most of them on remote NT machines, some central on AIX). I have no clue how many Unix sysadmins, NT admins, developpers, help desk agents, etc... there are - about 700 IT people in total. Due to heavy automation of the administrative tasks on the remote servers, we can handle a lot of them with a small team.

Do you agree that most problems (crashes) on the database are caused by the Operating System (in the case of NT) or the application? I'm not talking about development or implementation time, but when the thing has been set up and is running properly. I think RDBMSes are in general pretty stable and reliable monsters and if monitoring is well organised unpleasant surprises can almost completely be excluded.

BTW: A DBO is a DataBase Owner (it's Sybase speak, adopted by MicroSoft), somebody who has administrative rights within a particular database(and effectively owns the DB) but not necessarily in the whole RDBMS.

Koen.

Cherie_Machler%gelco.com_at_Internet
15/09/2000 15:06

To:	ORACLE-L%fatcity.com_at_Internet
cc:	 (bcc: Koen Lefever/GKBCCB)

Subject:	Re: How many databases do you support?

Suzy,

What is a DBO?

Cherie

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------------------------------

 From: "Belinda Taylor" <btaylor3_at_gmu.edu>
 Date: Fri, 15 Sep 2000 09:49:59 -0400
 Subject: Tuning SQL/Response

We are working with Coldfusion and Oracle on a simple database which
contains survey responses. I am having problems with response times from
simple SQL select statements. I added indexes to fields being used for
reporting purposes but nothing seems to help. Any suggestions for
reducing the response time. We are trying to keep the response times
down to 40 seconds; however, with no success.  Most of the SQL is going
against a table with approximately 70,000 records and growing.. Any
suggestions would be appreciated.







------------------------------

 From: ddorr.cs_at_clearstream.com
 Date: Fri, 15 Sep 2000 15:52:18 +0200
 Subject: RE: having multiple datafiles per tablespace vs. one datafile per



> ----------

> From: 	Steve Adams[SMTP:steve.adams_at_ixora.com.au]

> Reply To: 	ORACLE-L_at_fatcity.com

> Sent: 	Friday, September 15, 2000 16:30

> To: 	Multiple recipients of list ORACLE-L

> Subject: 	RE: having multiple datafiles per tablespace vs. one

> datafile per tablespace

> 

> Hi Babu,

> 

> The potential drawbacks of having multiple datafiles are trivial compared

> to the

> potential benefits.

> 

> On most platforms when you issue a CREATE TABLESPACE command with multiple

> datafiles, those datafiles will be "zeroed" in parallel by slave threads.

> Even

> on platforms that do not support this, you can do multiple ALTER

> TABLESPACE ADD

> DATAFILE commands in parallel.

	Hummm : I was under the impression ( not to say I was almost sure )
after some testing that if you have an ALTER TABLESPACE ADD DATAFILE running
in one session, and you perform another one elsewhere, it will wait for the
first one to complete before starting ...
	The workaround was to add small datafiles, and then resize them,
which could be done in parallel.

	But I may be wrong ..... as it often happens :-) 




>  Therefore multiple datafiles can make tablespace

> creation much faster.

> 

> For file system based databases, having multiple datafiles may reduce the

> risk

> of contention for the operating system's datafile read/write locks (inode

> locks).

> 

> Having multiple datafiles per tablespace facilitates the adoption of a

> uniform

> datafile size policy, which in turn facilitates disk load rebalancing.

> 

> Finally, I answered a related question on Ixora Answers a few weeks ago,

> and you

> may find that answer relevant. Look for the answer headed "Is AUTOEXTEND

> OK?" at

> http://www.ixora.com.au/q+a/0008/30150113.htm.

> 

> @   Regards,

> @   Steve Adams

> @   http://www.ixora.com.au/

> @   http://www.christianity.net.au/

> @

> @   Going to OpenWorld?

> @   Catch the Ixora performance tuning seminar too!

> @   See http://www.ixora.com.au/seminars/ for details.

> 

> 

> -----Original Message-----

> [mailto:babu.nagarajan_at_iflexsolutions.com]

> Sent: Friday, 15 September 2000 22:20

> To: ORACLE-L_at_fatcity.com; oracledba_at_lazydba.com

> tablespace

> 

> 

> Hi

> 

> Could any one point out the advantages/disadvantages of having multiple

> datafiles for a tablespace as against having one datafile per tablespace?