Maximum number of extends
Matthias asked whether there is a maximum number of extents for a table, having one with 199. Neil Truby confirmed it varies per table, usually about 240. Floyd Wellershaus gave a 9.4 method: oncheck -pP for the table's address, then oncheck -pP on that address for frcnt, with max extents = frcnt/8 plus current extents. Jon gave another formula from page size, columns and indexes.
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I can't beleve it ! We have a table in the database and the tabel hase 199 extents. Ok - we can enlarge the next extent size - but this is not the question. The question is: Is there a maximum for the numbers of extends? My associate told me that the maximum numbers of extends is different for each table. and i can not beleve.
Your associate is correct. It's a function of a number of variables, such as page size, number of columes and indexes etc etc. It's about 240 usually. -- Neil Truby t:01932 724027 Director m:07798 811708 Ardenta Limited e:neil.truby@ardenta.com "Matthias" <informixquestions@googlemail.com> wrote in message news:1147698011.491690.67370@g10g2000cwb.googlegroups.com... >I can't beleve it ! > > We have a table in the database and the tabel hase 199 extents. > > Ok - we can enlarge the next extent size - but this is not the > question. > > The question is: Is there a maximum for the numbers of extends? > > My associate told me that the maximum numbers of extends is different > for each table. > > and i can not beleve. >
Here's how to do it in 9.4
Do an oncheck -pP on the table and near the top get the Physical address of the table.
Say the address is 80:5. You would translate that for the next command into 0x80 5
Then do an oncheck -pP 0x80 5 and get the value for frcnt.
The formula for the max extents is:
frcnt/8 + ( number of extents in oncheck -pt) = Maximum number of extents.
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-<<Floyd Wellershaus>>-
Database Administrator
Unix Administrator
email: fwellers@yahoo.com
Home: 703-430-0805
Cell: 703-477-6045
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----- Original Message ----
From: Matthias <informixquestions@googlemail.com>
To: informix-list@iiug.org
Sent: Monday, May 15, 2006 9:00:11 AM
Subject: Maximum number of extends
I can't beleve it !
We have a table in the database and the tabel hase 199 extents.
Ok - we can enlarge the next extent size - but this is not the
question.
The question is: Is there a maximum for the numbers of extends?
My associate told me that the maximum numbers of extends is different
for each table.
and i can not beleve.
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I always used the following calculation (from 7.3 on up): ( pagesize - ( (4 x # of columns) + (12 x # of indexes) + (4 x # of columns in each index) + 84 ) ) / 8 Is this no longer valid? Jon