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.)
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.