Home » RDBMS Server » Performance Tuning » how to set DB_BLOCK_SIZE??????help meeeeeee......
how to set DB_BLOCK_SIZE??????help meeeeeee...... [message #159228] Thu, 16 February 2006 21:00 Go to next message
quytc
Messages: 81
Registered: November 2005
Location: Viet Nam
Member

HI ALL,
My database contain 1000 record. Size of a record is 250kb.

Can anybody help me to set size of DB_BLOCK_SIZE,PCT FREE,PCT USED,MAX EXTENTS... so that memory is used effectively and fast access
Re: how to set DB_BLOCK_SIZE??????help meeeeeee...... [message #159230 is a reply to message #159228] Thu, 16 February 2006 21:53 Go to previous messageGo to next message
newworld
Messages: 3
Registered: February 2006
Junior Member
You can not change DB_BLOCK_SIZE of a database. The only way to change this parameter is export the whole database, then drop the databse and recreate it, and import the database.

And you can use:
ALTER TABLE XXX PCTFREE 30 PCTUSED 50 MAXEXTENTS 100;
to change other parameters.
Re: how to set DB_BLOCK_SIZE??????help meeeeeee...... [message #159232 is a reply to message #159228] Thu, 16 February 2006 22:07 Go to previous messageGo to next message
quytc
Messages: 81
Registered: November 2005
Location: Viet Nam
Member

Hi newworld,
How i set db_block_size? 8000k? 7000k?.....
Re: how to set DB_BLOCK_SIZE??????help meeeeeee...... [message #159253 is a reply to message #159232] Fri, 17 February 2006 00:50 Go to previous messageGo to next message
quytc
Messages: 81
Registered: November 2005
Location: Viet Nam
Member

Can you tell me why you set PCTFREE 30, PCTUSED 50 and MAXEXTENTS 100
Re: how to set DB_BLOCK_SIZE??????help meeeeeee...... [message #159274 is a reply to message #159253] Fri, 17 February 2006 02:07 Go to previous messageGo to next message
newworld
Messages: 3
Registered: February 2006
Junior Member
DB_Block_Size is set to 4K~32K, you can't set it to 7000K. There is no need for you to change the DB_Block_Size, you can manully allocate some space to the table.

Usually, PCT_Free is set to 30, but it demands on your application. If you don't change the data in your table, you can set it to 0.
Re: how to set DB_BLOCK_SIZE??????help meeeeeee...... [message #159279 is a reply to message #159274] Fri, 17 February 2006 02:31 Go to previous messageGo to next message
quytc
Messages: 81
Registered: November 2005
Location: Viet Nam
Member

I know if db_block_size is not suitable with size of record, space free very large. because I want set db_block_size so that space free is small
Re: how to set DB_BLOCK_SIZE??????help meeeeeee...... [message #159280 is a reply to message #159279] Fri, 17 February 2006 02:54 Go to previous messageGo to next message
newworld
Messages: 3
Registered: February 2006
Junior Member
Why you hope a small free space?
Re: how to set DB_BLOCK_SIZE??????help meeeeeee...... [message #159283 is a reply to message #159228] Fri, 17 February 2006 03:05 Go to previous messageGo to next message
quytc
Messages: 81
Registered: November 2005
Location: Viet Nam
Member

Hi,

My database contain media data. Size of one record is 250KB, My database contain more than 30.000 record.

Can you help me set Db_block_size, PCTFREE,PCTUSED,MAXEXTENTS so that Database run effectively
Re: how to set DB_BLOCK_SIZE??????help meeeeeee...... [message #159357 is a reply to message #159228] Fri, 17 February 2006 12:31 Go to previous messageGo to next message
smartin
Messages: 1803
Registered: March 2005
Location: Jacksonville, Florida
Senior Member
I would suggest that you read the first couple chapters out of the concepts guide that discuss basic oracle architecture.
Re: how to set DB_BLOCK_SIZE??????help meeeeeee...... [message #159382 is a reply to message #159357] Fri, 17 February 2006 22:52 Go to previous message
rleishman
Messages: 3728
Registered: October 2005
Location: Melbourne, Australia
Senior Member
I agree with Scot. This whole conversation concerns me. You should not be mucking about with DB_BLOCK_SIZE unless you are an experienced DBA. And - to be honest - that doesn't sound like an accurate description of the OP.

And how the heck do you get a 250Kb record anyway? That's a lot of full VARCHAR(2000) columns!!!

And if the entire database contains only a thousand rows, that's only 250Mb. You can fit the entire thing in memory!!!

Here's the second best advice you'll ever receive: Get out the phone book and your cheque book, and get an EXPERIENCED Oracle DBA Consultant to come out for 4 hours. It might cost you a few thousand bucks, but it will save you heaps.
The people who respond to this forum are good (especially since the advice is free), but there are limits when they cannot see your database first hand, or speak to you directly in your native language.

_____________
Ross Leishman
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