M
mfurgal
Guest
Opinions will vary and it may get religious. I have seen many different type of implementation for storage areas and sizes of extents. Some made sense to me, others had me shaking my head. In my opinion, each Storage Area should be made up of us less than 10 extents (files). If the storage area is less than 10 GB, then 1 or 2 extents are fine. Large storage areas require larger extents, but there is no need to have 5 extents for a storage area that is less than 1 GB. Yes, I have seen this many times. I think what happens at times is that someone did something that made sense 10 years ago when the database was 20 GB, and now the database is 200 GB and the storage area design hasn’t been updated, so same sized files are added to storage areas that are growing so now the database is made up of a large number of smaller files. Final word on extent sizes. If your machine is fast (both CPU and Disk), then you can have large files. If the machine is slower, then you need smaller files. If you can do a database repair scan on a 64 GB extent in an hour or so, then 64 GB is a fine size. But if it takes 5-10 hours, then it is too large. I say this because all the repair utilities are based on extents. They can’t start in the middle of an extent, they always start either at the beginning or end of an extent to do it’s scanning. This will affect any disastrous repair downtime dramatically. And I know, no one ever thinks they will need to use these repair utilities. But if that was the case, we would have not built them. Mike -- Mike Furgal Director – Database and Pro2 Services PROGRESS 617-803-2870 mfurgal@progress.com
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