[Haskell-cafe] strange performance issue with takusen 0.8.3

[Marko Schütz]

Dear All,

I have an application where some simple data extracted from some
source files is inserted into a PostgreSQL database. The application
uses Takusen and is compiled with GHC 6.8.3. Some (59 in the test
data) of the selects take on average 460ms each for a total time for
this sample run of 30s. I prepare one select statement at the
beginning of the run into which I then bind the specific values for
every one of the selects. It does not seem to make a difference
whether I do this or whether I just use a new statement for every
select.

For comparison, I have collected the SQL statements in a file with
PREPARE ... and DEALLOCATE for _every_ select and then run this file
through psql. This takes 2s!

During the run of the GHC-compiled executable the cpu load goes up. In
top I see %CPU of above 72%.

Any ideas that might enlighten are welcome.

Best regards,

Marko
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