Archives of the TeradataForum
Message Posted: Wed, 05 Mar 2008 @ 11:15:53 GMT
| Subj: || || Re: ODBC Connect to Teradata |
| From: || || Victor Sokovin |
| ||So I would like to understand the reason. I mean I was running several other explains which took up to 10 Seconds but they haven't been
that huge. The explanation I have (more my assumption) is that the ODBC Driver is parsing the SQL before it will be send out to the Database. We
tried to uncheck this section in the ODBC Driver but we got then an Error.|| |
The driver not only parses the query but sometimes it would even attempt to rewrite it. The main reason for this is that ODBC offers extensions
to native SQL and the driver needs to translate them to the SQL that the Teradata engine understands. If you enable tracing in the ODBC driver you
can check what exactly the result of this translation was.
You didn't specify which error you received when you disabled the parsing. Try to investigate what type of SQL Cognos generates. Does it
really use ODBC extensions? If it does, then disabling the parsing is not an option.
If Cognos produces "clean" SQL which Teradata should understand without the translation services of the ODBC driver you may try to investigate
what prevents you from disabling the parsing. I never tried to bypass the parsing so I can't advise further on this path. The parsing time does
not surprise me, though, with the size of SQL you submit.