Hi John, the current version of the MySQL interface reads the complete result set from the DB server into the client memory, so you must have enough RAM and swap. Cheers, Fons. On Tue, 2003-07-08 at 21:15, Dr. John Krane wrote: > Hi, > > I need to run over many millions of events in an SQL database. From the > way my tree-making code is behaving, it looks like TSQLServer.Query() > pulls over all the information at once and stores it in memory, then my > code runs over the TSQLResult from that memory. It is unclear to me if > the memory is disk-resident but I think it must be. > > Is there some buffer size limit or is this TSQLResult written to an > intermediate file or ??? I'm really having difficulty with my system > freezing if I request more than 3 million events. Less than 3M and I do > not freeze. Could somebody please explain how TSQLServer.Query handles > large results? My disk drive is enormous so I really can't run out of > disk space if I am allowed to define a buffer area. I might be in > trouble if it is hard-wired to /tmp on my Linux box. > > - John -- Org: CERN, European Laboratory for Particle Physics. Mail: 1211 Geneve 23, Switzerland E-Mail: Fons.Rademakers@cern.ch Phone: +41 22 7679248 WWW: http://root.cern.ch/~rdm/ Fax: +41 22 7679480
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