[AccessD] Make-Table Queries Combined

Hi List,

A friend's company has this situation:  

A particular report is actually based on about 32 make-table queries. 
 Running them one at a time works well, but requires someone to run each 
one in sequence.  My friend combined these small queries into a big one 
that gathers them all together.  He finds that when it gets to about the 
14th query, everything slows down to a crawl.  In fact, it may take up 
to 12 hours for the large combining query to finish its job.  I don't 
know anything more about this situation.

Does anyone here know why this happens?  Is it something like the system 
has to keep everything in memory until the query finishes?  

Thanks for your thoughts.

Tina