what's db_block_size if it's not configured at all in init.ora ??

hi experts,

If i dont specify any db_block_size in init.ora file where does Oracle set this value from?? is it the system ?

Parameter type: Integer

Parameter class: Static

Default value: Operating system dependent

Range of values: 2048 to 32768, but your operating system may have a narrower range

Oracle Parallel Server: You must set this parameter for every instance, and multiple instances must have the same value



RTFM

hi,

I am using Solaris 2.6 how can i chk wat's my OS block size?
I am new to unix :)

10-q

Quote:

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Originally posted by ngwh
I am using Solaris 2.6 how can i chk wat's my OS block size?
10-q

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Code:

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ORACLE: SYS> select max(lebsz) from sys.x$kccle;

MAX(LEBSZ)
----------
      512

ORACLE: SYS>

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Check this out...

http://www.ixora.com.au/notes/log_block_size.htm

HTH.

hi ggnan,

I used your method and i got 512 as the result but when i query the parameters in oracle it return db_block_size =2048 so I was wondering where exactly in Solaris I can confirm the OS block size?

Quote:

---

Originally posted by ngwh
hi ggnan,

I used your method and i got 512 as the result but when i query the parameters in oracle it return db_block_size =2048 so I was wondering where exactly in Solaris I can confirm the OS block size?

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512 is the OS block size and 2048 is the DB block size, DB block size should always be multiple of OS block size...

Quote:

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Originally posted by ngwh
hi,

I am new to unix :)

10-q

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I think you are new to oracle as well

RTFM

Correct me if i am wrong.

OS block size specified durin installation

oracle block size has to be multiple of OS block size.In your case, 4 OS blocks make up 1 Oracle datablock

oh..in that case how can i know how many times are Oracle block size are in terms of OS size?? since it wasn't specified in init.ora ??

Quote:

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Originally posted by ngwh

oh..in that case how can i know how many times are Oracle block size are in terms of OS size?? since it wasn't specified in init.ora ??

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Quote:

---

Originally posted by ngwh
hi ggnan,

I used your method and i got 512 as the result but when i query the parameters in oracle it return db_block_size =2048 so I was wondering where exactly in Solaris I can confirm the OS block size?

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Its elementary my dear watson.

divide 2048 by 512

Hi

I think that 512k is the os block size..for all practical purposes you can ignore this..as the most important thing is the file system block size..In solaris you can see that like this

uname -a
SunOS aha 5.8 Generic_108528-11 sun4u sparc SUNW,Ultra-5_10


ahah:agag >df -g|grep "block"


/ (/dev/dsk/c0t0d0s0 ): 8192 block size 1024
6014172 total blocks 718056 free blocks 597774 available 509952 s
/proc (/proc ): 512 block size 512
0 total blocks 0 free blocks 0 available 7916 s
/dev/fd (fd ): 1024 block size 1024
0 total blocks 0 free blocks 0 available 63 s
/etc/mnttab (mnttab ): 512 block size 512
0 total blocks 0 free blocks 0 available 1 s
/var/run (swap ): 8192 block size 8192
1963616 total blocks 1963600 free blocks 1963600 available 54175 s
/tmp (swap ): 8192 block size 8192
2031248 total blocks 1963600 free blocks 1963600 available 54175 s
/data (/dev/dsk/c0t0d0s3 ): 8192 block size 1024
31153540 total blocks 1523686 free blocks 1212152 available 1964928 s

regards
Hrishy