Re^2: CSV Manipulation

This. If I have a choice, and I usually do, I use DBD::CSV. It makes me think about the data as data rather than a string, and has the added advantage of making transitioning to SQLite or a full-fledged RDBMS (DB2, Oracle, etc.) easier.

Comment on Re^2: CSV Manipulation

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Re^3: CSV Manipulation by Tux (Canon) on Nov 17, 2011 at 09:47 UTC
One note here. The OP did not mention the size of the CSV data file. DBD::CSV uses Text::CSV_XS under the hood, but it will have to read the complete file into memory to be able to do any database-like operations. With a file of 2Gb, that might result in say 20Gb of memory use (perl overhead). When files are that big - again, I don't know how large the file of the OP is - switching to basic streamed IO processing is usually a lot easier. I fully agree though that DBD::CSV is the best step towards RDBMS's where those memory limits are not applicable (for the end-user script). YMMV update: I just did a quick test with the OP data extended to a 1Mb CSV file. Reading that into memory using getline_all () resulted in a 10Mb data structure (reported by Devel::Size::total_size ()). Enjoy, Have FUN! H.Merijn	[reply]

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Re^3: CSV Manipulation
by Tux (Canon) on Nov 17, 2011 at 09:47 UTC

One note here. The OP did not mention the size of the CSV data file. DBD::CSV uses Text::CSV_XS under the hood, but it will have to read the complete file into memory to be able to do any database-like operations. With a file of 2Gb, that might result in say 20Gb of memory use (perl overhead). When files are that big - again, I don't know how large the file of the OP is - switching to basic streamed IO processing is usually a lot easier.

I fully agree though that DBD::CSV is the best step towards RDBMS's where those memory limits are not applicable (for the end-user script).

YMMV

update: I just did a quick test with the OP data extended to a 1Mb CSV file. Reading that into memory using getline_all () resulted in a 10Mb data structure (reported by Devel::Size::total_size ()).

Enjoy, Have FUN! H.Merijn

[reply]