I am doing some calculations based on the graph generated by hyperlinks on the web. I have one huge file (~500GB), in which the nth line corresponds to all nodes in the graph adjacent to the nth node; the file is a list of adjacency lists.

For my calculations I need to access lines in this file at random based on my calculations, since obviously this data is way to much for any more advanced data structure. The question is, what is the fastest way to access lines in such a huge file at random?

The way I see it, I have a few options:

  1. linear search
  2. try my luck with Tie::File
  3. find the longest line, pad each line so all lines are the same length, and use byte offsets to access lines with seek (or something)
  4. find number of bytes on each line, maintain auxiliary data structure (BerkeleyDB?) storing byte to line offset

Ordinarily I would try to do this in C++, but since I discovered perl, I have a high level of faith in its capabilities. This is my first post, I welcome your advice!

In reply to Help performing "random" access on very very large file by downer

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