Data Access Worldwide Knowledge Base
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QUESTION:
How does field length influence the performance when long fields are used in indexes?
ANSWER:
Using the embedded database, the actual length of ASCII index segments "matters" because it increases the key length, which increases the number of levels, which increases the amount of index blocks that have to round-trip for all index operations - in other words, excessive index length can be expensive.
However, in Pervasive.SQL this doesn't really matter, at least not in the same way, because all index operations take place at the server. There is a limit to the number of total segments in PSQL (but you wouldn't be changing that) and there is a limit on where in the record layout indexed fields must live (but you wouldn't be changing that either).
Contributed By:
Stephen Meeley
Company: Data Access Worldwide
Web Site: http://www.dataaccess.com
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