Set primary extent size?
Posted on 2007-11-17
I'm working on an ooooold INFORMIX 5.10 database, and want to change the "primary" extent (if that's what it's called) to say 1.5 times the current size of the loaded data, to maximise performance and allow for 50% growth without going into "secondary" extents (or is it "next"? extents). The current data is badly fragmented, and the extent sizes are too small, so I plan to export, delete, and import the database.
1. What is the correct term for this "primary" extent?
2. Does trying to avoid using next extents sound like a good way to maximise performance? (Yes, I know there are many other ways - I'm just talking about this one).
3. I know how to set the next extent sizes ("ALTER TABLE...MODIFY NEXT SIZE..."), but how can I go about making the "primary"? extent 50% larger than the current data requirement?
4. Could I achieve item 3 by increasing the row counts in the dbexport file (after the export) by 50%, and then import?
5. Do those row counts in the dbexport file have to match the numbers of rows in the table unload files, for the dbimport to work?
6. Can the primary extent span chunks? (I understand that next extents can't).