Get I/O buffer size of operating system...

Question

Hi ,
Is there any script in Oracle which will display the I/O buffer size of operating system i use???
I need it in order to set appropriately the parameter DB_FILE_MULTIBLOCK_READ_COUNT.
Thanks , a lot
Simon

Answer 1

Hi ,
I found a script in order to find the IO buffer size of operating system. This is as follows:
create tablespace tester datafile 'C:\oracle\product\10.2.0\oradata\EPESY\test.dbf' size 10M reuse
default storage (initial 1M next 1m pctincrease 0)
create table testing tablespace tester
as select * from all_objects
where rownum<50000
select relative_fno from dba_data_files
where tablespace_name='TESTER'
select phyrds,phyblkrd from v$filestat where file#=<#relative_fno#>
select count(*) from testing
select phyrds,phyblkrd from v$filestat where file#=<#relative_fno#>
In an example - explaining the above example- there were the following figures:
select phyrds,phyblkrd from v$filestat where file#=<#relative_fno#>
PHYRDS PHYBLKRD
154 1220
The test ends up by dividing the PHYBLKRD by the PHYRDS . So in the above example it yields a result of 7.92 which is close to 8 - so the effective multiblock read count is 8.
NOTE : The words underlined are of the author words not mine.
I run the above script and i found a figure about 10.85. So which may be the effective multiblock read count...??????
Thanks , a lot
Simon