Subject Re: [IBO] What decrements in server performance result from open queries
Author Helen Borrie
At 01:40 PM 18/06/2004 +0000, you wrote:
>If i open a TIB_Query in a read-only transaction mode, read it into a
>TIB_Grid and keep it open through the session, what decrements in
>server
>performance will result?

None, as long as you make sure the transaction is in ReadCommitted
isolation. If you use Concurrency isolation, it will lock up the garbage
collection and cause your application to grind to a halt eventually. Also,
Refresh the dataset from time to time and whenever you want to read a value
from it. Don't be deluded into thinking this is a way to work around the
problems of maintaining huge datasets on clients, though.

>This query will be open on each client
>machine
>logged onto the database. The option is to add the 2 columns I need
>into a
>listbox and then close the query. The two columns are the primary
>key and
>client full name that are used as a pick list to search the database,
>with
>the primary key a parameter for the query that calls up entire client
>records.

You could do this too: fetch these values in a method, via a TIB_Cursor,
and call the method when required to bring the values up to
date. Obviously, it is not "real-time" data, so don't use this approach
for data that are likely to be updated. It's fine for "control" and "type"
tables, though.

Helen