Hello,

Thanks

The grep regex on the text file found around 10,000 lines over 5 minutes 
(out of a total possible 200,000 rows), at which time I stopped it, 
interesting experiment anyway :-)

Using OR instead of UNION in Mysql is definitely slower, although maybe, 
as someone has mentioned above, the Sqlite optimizer works better with 
OR. Will try that next.

Thanks.


> Try this:
>
> (1) ditch the redundant commas in your csv file
> (2) run this (suitably adjusted for my errors and typos, and for my
> ignorance of the minutiae of command-line and grep syntax on your
> [unspecified IIRC] OS):
>
> grep
> "(....W[CEF][SZ]|..W[CEF]S|...W[CEF]S|W[3CEF]S[25]..|W3S..|.11[CEF]S.),"
> yourfile.csv
>
> How long does that take?
>
> Another suggestion: search for clues on whether it might be better
> instead of doing
>     select * from mytable where <critera1>
>     union all
>     etc etc
>     select * from mytable where <criteria7>
> to do
>     select * from mytable where <criteria1> or <criteria2> or etc etc
> and if you don't find a strong weight of opinion for one way or the
> other, give it a try.
>
> HTH,
>
> John
>
>
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