> I was wandering what MI (7.5) does to Oracle (9.2) when querying a table in the > direct mode.
Do you perform this query using the SQL Select or do you send the query to Oracle using the DBMS expert ? If you send the query to Oracle you can use the power of Oracle to get a much better performance, and this also prevents MapInfo from retrieving all records from the Oracle database before actually doing the query. If you use the DBMS Expert MapInfo only needs to retrieve the records that fits your query. As far as I know you can speed up things if you keep a rowcount in the MAPINFO_MAPCATALOG. Mayby this could prevent MapInfo from performing the last query (Select count(*) ...) But anyway it sure looks strange that the same query is performed twice !! Peter Horsbøll Møller GIS Developer Geographical Information & IT COWI A/S Odensevej 95 DK-5260 Odense S Denmark Tel +45 6311 4900 Direct +45 6311 4908 Mob +45 5156 1045 Fax +45 6311 4949 E-mail [EMAIL PROTECTED] http://www.cowi.dk *****CHANGE OF ADDRESS - COWI's offices in Odense are now under the same roof***** On December 8th. 2003, Geographical Information & IT moved from Rugaardsvej 55, 5000 Odense C to Odensevej 95, 5260 Odense S. Please note our new telephone, direct and telefax numbers. > -----Original Message----- > From: Christof Kaiser [mailto:[EMAIL PROTECTED] > Sent: Wednesday, January 14, 2004 3:44 PM > To: '[EMAIL PROTECTED]' > Subject: MI-L SQL statements when accessing Oracle Spatial from MI 7.5 > > > Hello, > > I was wandering what MI (7.5) does to Oracle (9.2) when > querying a table in the direct mode. > It seemed to be "awfully slow" up to "not working at all" for > bigger tables (millions of rows). > > So we eventually did a database trace on Oracle while > connecting to the table. > The statements that are sent to the to the database are: > > select * from table; ## what the hell do > we need all rows > for? > select * from table; ## yes, better do it > twice. you never > know... > select count(*) from table; ## ok, forgot to > count during the last > two selects ... > > after that, a statement with a nice spatial operator is used. > that is how it > should be. > > but due to the three initial selects, MI seems to be unusable > with bigger > tables form Oracle. > anybody experienced the same porbs or even has a solution? > > Cheers > Christof Kaiser > > > --------------------------------------------------------------------- > List hosting provided by Directions Magazine | www.directionsmag.com | > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: > [EMAIL PROTECTED] > Message number: 9878 > > > --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 9888
