Thanks a lot Jim.

Udayangi

On Mar 12, 11:57 am, Jim Idle <[email protected]> wrote:
> udayangi wrote:
> > Thanks Jim for your quick reply.  Yes I do use jrf -R to find out the
> > jrf recommendation.  I am not sure how to get the seperation from the
> > jstat.  In the below jstat what would be the seperation.  I can see
> > the modulo is derived by applying the following.
>
> > (574075 x 676)/3735
>
> > jsh globdev ~ -->jstat -v F.SECURITY.MASTER
> > File ../bnk.data/sc/F.SECU000
> > Type=J4 , Hash method = 3
> > Created at Sat Dec 13 10:39:21 2008
> > Groups = 103937 , Frame size = 4096 bytes , Secondary Record Size =
> > 8192 bytes
> > Restore re-size parameters : (none)
> > File size = 586186752 bytes , Inode = 592637 , Device = Id
> > 3211265
> > Last Accessed Wed Mar 11 10:02:42 2009 , Last Modified Wed Mar 11
> > 10:02:42 2009
> > Backup = YES , Log = YES , Rollback = YES , Network = AUTO
> > Secondary control file = ../bnk.data/sc/F.SECU000]I
>
> > Record Count = 574075 , Record Bytes = 388259006
> > Bytes/Record = 676 , Bytes/Group = 3735
> > Primary   file space:   Total Frames = 142853 , Total Bytes =
> > 388259006
> > Secondary file space:   Total Frames = 0 , Total Bytes = 0
>
> The modulo isn't that useful in J4 files, but some experimentation may
> get you a something sometimes.
>
> The separation is a multiple of the base frame size, which is 4096
> bytes. As this file has a frame size of 4096 bytes, it has a separation
> of one. The secondary record size is the size beyond which a record will
> be placed into secondary space in the file and the group will use a
> pointer to point to the record in contiguous disk space. So here, if the
> record is less than two 'frames' in length it will be stored within the
> group, and after that it will be a pointer in the group to secondary
> space allocated at the end of the file.
>
> As the bytes per record is only 676 on average then there is no need for
> a separation anyway. jrf also allocates about 10% growing room, so it
> isn't dividing by 3735
>
> Jim- Hide quoted text -
>
> - Show quoted text -

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