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how to reset parameter DB_FILE_MULTIBLOCK_READ_COUNT on Oracle 10.2 ?

Former Member
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Hi

how to reset parameter DB_FILE_MULTIBLOCK_READ_COUNT on Oracle 10.2 ?

Accepted Solutions (0)

Answers (2)

Answers (2)

Former Member
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Hello,

I have to say I do NOT agree with Vinod ( sorry )

The original question is

<i>> how to reset parameter DB_FILE_MULTIBLOCK_READ_COUNT on Oracle 10.2 ?</i>

This is a strong recommendation from oracle and it is reflected on the note <a href="http://service.sap.com/sap/support/notes/830576">830576</a>


DB_FILE_MULTIBLOCK_READ_COUNT    Do not set  

This recommendatio is <u><b>TOTALLY </b></u> different from the one given by Vinod:

<i>


> ALTER SESSION SET DB_FILE_MULTIBLOCK_READ_COUNT =<value>;

</i>

where you are <u>setting</u> the parameter to one specific value. What oracle and SAP and requesting is to <u>delete</u> the parameter in order to Oracle calculate the value based on the system statistics.

If you still are using spfile ( init<sid>.ora ) then you have to <u><i>delete</i></u> the parameter from this file ( or comment it )

If you are using spfile you have to do:


SQL>ALTER SYSTEM RESET <parameter_name> scope = spfile sid = '*';

Message was edited by:

Fidel Vales

Former Member
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Hi,

For the question how to reset parameter DB_FILE_MULTIBLOCK_READ_COUNT on Oracle 10.2 ?

I thought requestor might be instd in setting this and offcourse he tried it as 128.

So based on reply from requestor i got confused and even i was thinking and waiting for his reply. I got confused with his intention.

but As u said my ans was abs'ly wrong if this is the case for RESET.

And I was thinking Eventhough parameter is set oracle calculates it self based on OS.

Each version of Oracle on each port, is shipped with a preset maximum of how much data can be transferred in a single read (which of course is equivalent to the db_file_multiblock_read_count since the block size is fixed). For 8i and above (on most platforms) this is 1Mb and is referred to as SSTIOMAX.To determine it for your port and Oracle version, simply set db_file_multiblock_read_count to a

nonsensical value and Oracle will size it down for you.

by this point i suggested him value 16 which is within normal range for OLTP systems.

Any way for my wrong answer I apologize.

SQL>ALTER SYSTEM RESET <parameter_name> scope = spfile sid = '*';

is the one which shd be used to RESET.

Now becoz of some pressure points are needed by me. I never entertain points for wrong ans.But I kindly request you to remove last lines from posting.

Regards

Vinod

Former Member
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No problem,

As mentioned, I think you are doing a good job in the forums ( at least in this one )

but I wanted to clarify that the answer ( to this specific question ) was wrong.

And it is a confusion <i>I</i> see a lot.

Former Member
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Hi,

sql>ALTER SESSION SET DB_FILE_MULTIBLOCK_READ_COUNT =<value>;

sql>ALTER SYSTEM SET DB_FILE_MULTIBLOCK_READ_COUNT =<value>;

Regards

Vinod

Former Member
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by starting checkdb i see "Database profile alert - level: WARNING, parameter: DB_FILE_MULTIBLOCK_READ_COUNT, value: 128 (set in parameter file)".

note 830567 gives recomendation - don't set. How to don't set?

Former Member
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Hi,

sql>ALTER SYSTEM SET DB_FILE_MULTIBLOCK_READ_COUNT =<old_value>;

Regards

Vinod

Former Member
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i don't know <old value>

is that 16, or 8, or 128

Former Member
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Dear Denis,

Set it to 16, and close thread.

Regards

Vinod

Message was edited by:

Vinod U