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Issue with concurrent ODBC connections in FMS16 and FMS17.

Question asked by mhamilton on Aug 21, 2018
Latest reply on Aug 29, 2018 by mhamilton

ODBC queries cannot execute at the same time. It appears they are queued. Only executing one at a time.

 

This issue does not occur in FMS 15 (or prior.)

 

To replicate:

 

Design two standard SQL select queries which give a fairly consistent execution time.      (Any table. Not using calculations, not using joins. Standard flat query.)

The first – a more complicated query ~ 48 seconds

The second – a smaller query ~0.02 seconds

 

- Run the complicated query.

- Instantly, after starting the first query. (before it has finished executing.) run the second smaller query, in a separate window/session/etc.

 

Results in FMS15

-The first query will take ~48 seconds

-The second query will take ~0.02 seconds

 

Results in FMS16/17 (Different Physical Server)

-The first query will take ~25 seconds

-the second query will take ~15 seconds

 

Using FMS16/17, we have also tried using different versions of the ODBC driver (15,16,17). It does not change the result.

 

Note – by ‘more complicated query’ I mean a complex WHERE clause in the query. A higher execution time, not simply reading more rows.
Separating a query into two steps. Execution time and Read time… it appears that two queries cannot EXECUTE at the same time.
Reading the results of a query, will not prevent other queries from executing or reading.

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