Kbase 16762: Disk Space Requirements with Index Compression in Version 7
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
5/10/1998 |
|
Disk Space Requirements with Index Compression in Version 7
This kbase is being generated to provide some general information on
Disk Space Requirements when considering "Index Compression" which
was introduced with Version 7 of Progress.
The difference in index size between version 6 and version 7 is
difficult to calculate because the compression scheme relies on
eliminating redundant data in an index. The more redundant the data,
the better the compression.
On the average, v7 indexes will be approximately half the size of the
same v6 index. This can vary from one db to another, based on the
amount of redundant data in the indexes, as well as the # of index
blocks being utilized to store the redundant information. i.e.
"Your mileage may vary".
When you convert a database from v6 to v7, the indexes become smaller,
usually resulting in more free blocks. If a very small index occupies
only a single index block. If it is compressed, it still occupies one
index block, but there is more empty space in it. So in a case like
that, the database size is not affected at all.
Where will the customer see the benefit of the index compression?
The customer sees the benefit of index compression when the database
has data in it and there is something to compress. Freshly loaded v7
databases will almost always be smaller than freshly loaded v6
databases that contain the same data.
Progress Software Technical Support Note # 16762