Fwd: Re[2]: How to generate Alter Table modify next entent s
Sujit is correct. The entry is also in the Version 7.3 Performance Guide on
page 4-32. My apologies if I misled.
---- Original Msg from: Sujit Pal <Sujit.Pal@alltel.com> At: 12/17 15:32
Art
You wrote:
> There is no maximum number of extents in a table;
but in the Performance Guide version 7.2 page 3-28 it says:
"Do not allow a table to acquire a large number of extents because an
upper limit exists on the number of extents allowed..."
It goes on to say how one should calculate the max number of extents
for a given table. Has this restriction been removed?
Sujit
______________________________ Reply Separator _________________________________
Subject: Re: How to generate Alter Table modify next entent size?
Author: kagel@bloomberg.net (Art S. Kagel) at internet
Date: 12/17/1998 1:51 PM
dengelsen@my-dejanews.com wrote:
> Hello,
> How to generate Alter Table modify next entent size?
> Currently I've tables with 100+ extents. I've used the following script with
> dbaccess to display al tables with 100+ extents.
[SNIP]
> Now I want to modify the next extentsizes from these tables. I would like to
> have a script that produces the following output
> ALTER TABLE tabname MODIFY NEXT SIZE <current NE_VALUE *2>
> How do I get this current next extent size?
> Am I doing the right thing?
> Do you have a script to does do this?
> What is the max number of extents for informix tables (pagesize=2k)?
[SNIP]
The table's current next extent size is stored in systables in the
database that 'owns' the table it is the column 'nextsize' or in
sysmaster in the table sysptnhdr as column 'nextsiz' (no 'e'). Both
columns are maintained live so they reflect the latest extent doubling
value.
There is no maximum number of extents in a table; however detached
indexes DO have a maximum number of extents and their extent size is
automatically calculated from the table's extent sizes as the extent
size times the ratio of the rowsize to the index keysize plus overhead
bytes. The only limit on a table's size is that no single table
fragment,
as in "FRAGMENT BY", can exceed 16777215 pages but since the number of
table fragments is only limited to how quickly you finger wear out
typing
the fragmentation expressions that is no problem.
Art S. Kagel