Hi, Original from: [EMAIL PROTECTED]
> Where do I change autocommit? Is it more efficient if I > issue a commit > every 500 rows? This depends on the length of the rows you are inserting, your configuration and the number of working DB-Sessions. The best will be to try it out. Remember: All operations were buffered before they are written into the log. Only a commit always triggers a log-access. So, increasing the number of rows insertet in one transaction is generaly a good idea - until you reach the borders of your system or configuration. > I just didn't specify any hostname. Then you are unsing a local connection. Thats good. > I just issue SQL statement litterals. Indeed mySQL does not > plan that > feature till their version 5. This will propably be a big (BIG!) performance trap. > I need to save as many intermediary results as possible. If > the result > does not exist in the database it is recalculated. > > At this point it becomes clear that no DB engine seems to be able to > handle one GB of data speedily without souped up hardware. One GB of data aint so much. The "usual" open-source DB-systems (including SAP DB, of course ;-) should have no problem with this amount of data on a "normal" PC-system. > Considering the cost of RAM one wonders if it would not be [... data in RAM, compression ...] > set intervals? Does it compress data? SAP DB attempts to make all operations in RAM. If you set your data-cache large enough, your DB-instance will access the harddisks (nearly) only for logging during your inserts. To compress data is generaly a bad idea for databases: a decompress would be neccessary not only for the output-data, but also for inserting (it has to be sorted in the rows), searching, joining.... You would spend more money into CPUs to get your performance back than in extra RAM to store the uncompressed data. This is why we do not compress our data. Bye, Falko _______________________________________________ sapdb.general mailing list [EMAIL PROTECTED] http://listserv.sap.com/mailman/listinfo/sapdb.general
