SQLServer Driver - Performance Bottleneck

hi
i'm using a type 4 SQL Server driver. The application is running on Tomcat 5.0. When I execute certain select queries, the executeQuery method is taking a lot of time. But wen the same query is executed again it works fast. But wen u modify this query and execute again it takes long time. But if the same query is executed directly using SQL Server client, it works fast and consistently.
The selectMethod used is Cursor.
Solutions and suggestions are appreciated.
Thanx,
Sandeep

Sandeep,
The Microsoft driver has big performance problems with selectMethod=cursor. All ResultSets generate cursors which then require one request/response for each row that is retrieved. However, this doesn't seem to be causing your problem since you say it works well enough with "certain select queries".
The other reason why this could be happening is Unicode vs. specific character set encodings. If strings are not sent in the same encoding as they are stored in, SQL Server will perform an index scan instead of an index seek (i.e. it won't be able to actually use the indexes and will have to do a sequential search). Most SQL Server drivers support a sendStringParametersAsUnicode parameter to specify whether strings should be sent in Unicode or the database encoding.
Alin,
The jTDS Project.

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Array as shared memory - performance bottleneck
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"David Ruana" <[email protected]> wrote in message
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Hello,
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