[ROOT] TSQLServer.Query() : buffer size limit? timeout?

From: Dr. John Krane (jkrane@fnal.gov)
Date: Tue Jul 08 2003 - 21:15:33 MEST


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



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