question about the nature of DBM ties

[Peter Scott]

At 01:09 PM 9/24/2002 -0700, nkuipers wrote:
>When you tie a data structure to an external file, is populating that
>structure for large input updating directly into the file or is it crowding
>more and more stuff into memory which then gets dumped into the file, or what?
>  In other words, does tying in this manner free up more RAM?  The bottleneck
>in my code is the unique function but this function is necessary.  All in all
>the code works perfectly but takes too long.

I'm in the middle of an exercise break for my students, so I don't have 
long, but one thing I will suggest you check for is constructs which 
vitiate the use of tie.  For instance,

         keys %tied_hash

makes the tie-ing pointless since it constructs the list of all the keys in 
memory.  Look for the use of any lists like these:

         keys %hash
         values %hash
         %hash in list context

and get rid of them.  Use only each() for iterating through the hash.
Peter Scott
peter at psdt.com
http://www.perldebugged.com