What are the benefits of increasing and decreasing those numbers when creating
a table?

Abdulaziz,

<< What are the benefits of increasing and decreasing those numbers when
creating a table? >>

Increasing them naturally increases the size of the I/O block size that
DBISAM uses when reading/writing to the index or BLOB file.  This can
improve performance at the cost of possibly larger space consumption.  If
you've got a table that has very large index keys or BLOBs, then increasing
these values can lead to better performance.

--
Tim Young
Elevate Software
www.elevatesoft.com

Tim,

<<Increasing them naturally increases the size of the I/O block size that
DBISAM uses when reading/writing to the index or BLOB file.  This can
improve performance at the cost of possibly larger space consumption.  If
you've got a table that has very large index keys or BLOBs, then increasing
these values can lead to better performance.>>

What if we have little data stored in those blob fields (around 100 bytes)?  Should we reduce the Blob block size to a smaller number like 64 or keep
at as 512?  When we developed our application we where expecting kilos of data but in the real word we found little data and big BLB files.  Another
concern, what if we changed it to a smaller number like 64 well the performance be affected?

Abdulaziz,

<< What if we have little data stored in those blob fields (around 100
bytes)?  Should we reduce the Blob block size to a smaller number like 64 or
keep at as 512?  When we developed our application we where expecting kilos
of data but in the real word we found little data and big BLB files. >>

I would put it at 128 bytes if the average BLOB size is around 100 bytes.

<< Another concern, what if we changed it to a smaller number like 64 well
the performance be affected? >>

Not if all of the BLOBs are actually around 100 bytes, as you say.  However,
if someone stores a large BLOB (multiple megs) then the performance could go
in the toilet due to the small block size.

--
Tim Young
Elevate Software
www.elevatesoft.com

Tim,

<<Not if all of the BLOBs are actually around 100 bytes, as you say.  However,
if someone stores a large BLOB (multiple megs) then the performance could go
in the toilet due to the small block size.>>

I got the message..thanks