Transforming ascii file (pseduo database) into proper database
ppetrick at gmail.com
Mon Jan 21 23:41:18 CET 2008
So in answer to some of the questions:
- There are about 15 files, each roughly representing a table.
- Within the files, each line represents a record.
- The formatting for the lines is like so:
Where ID is the one and only value linking "records" from one file to
"records" in another file - moreover, as far as I can tell, the
relationships are all 1:1 (or 1:0) (I don't have the full dataset yet,
just a sampling, so I'm flying a bit in the dark).
- I believe that individual "records" within each of the files is
unique with respect to the identifier (again, not certain because I'm
only working with sample data).
- As the example shows, the position of the ID is not the same for all
- I don't know how big N is since I only have a sample to work with,
and probably won't get the full dataset anytime soon. (Lets just take
it as a given that I won't get that information until AFTER a first
- I don't know how many identifiers either, although it has to be at
least as large as the number of lines in the largest file (again, I
don't have the actual data yet).
So as an exercise, lets assume 800MB file, each line of data taking up
roughly 150B (guesstimate - based on examination of sample data)...so
roughly 5.3 million unique IDs.
With that size, I'll have to load them into temp db. I just can't see
holding that much data in memory...
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