Can you cache information? If files only grow with time, and your filters are constant, you could record for each line written to the file (or better, for each line read from the file) which filter(s) it matches. Using a bit-vector for each filter, and a single bit per line, you only need 125k of storage per filter for a million line file.

In reply to Re^3: Further on buffering huge text files by Anonymous Monk
in thread Further on buffering huge text files by spurperl

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