Sanity check on use of dictionaries

[dopey483 at gmail.com]

I am manipulating lots of log files (about 500,000 files and about 30Gb
in total) to get them into a little SQL db. Part of this process is
"normalisation" and creating tables of common data. I am creating
dictionaries for these in a simple {value,key} form.

In terms of memory and performance what are the reasonable limits for a
dictionary with a key and a 16 character string? eg; if I read in one
of my tables from disk into a dictionary, what sizing is comfortable?
100,000 entries? 1,000,000 entries? Lookup times and memory
requirements are my main worries.

(Running Python 2.3.4 on RH Ent, dual-Xeon with 2GB memory)