Philosophy on Map Files

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by Torrie Moore >> Tue, 26 Jun 2001 6:23:07 GMT

Hi John

There may be a performance advantage by putting collections in a different map file (or parent object with exclusive collections). In a large system the map files can be put on separate disks increasing the performance and head movement is not an issue.

Torrie Moore

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by John Porter >> Fri, 28 Sep 2001 4:51:34 GMT

In a large system, raid disk would normally be used, which automatically provides the benefit of spreading across multiple physical disks without having to design that into your mappings. In that case there is benefit to keeping the collections with either the parent or child objects (as Craig points out, with exclusive collections they can only be with their parent).

Assigning to different drive letters in a raid situation may actually slow it down, as multiple drives are frequently configured onto different areas of the same physical drives (similar to multiple partitions on your desktop's hard drive), guaranteeing more head movement.

Cheers,
John P

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by Craig Shearer >> Fri, 22 Jun 2001 1:43:46 GMT

I would have thought that somebody from the plant would have commented on this... where are you all?

Craig.