Evans, Matthew mevans@REDACTED
Tue Jun 16 05:34:47 CEST 2009

I appear to have answered my own question. It is significantly slower.

I had to add an extra record that let me bound my search. Maybe this is something to add as a request to the Eralng team; the ability to force the number of records returned from mnesia:select/4, without having to get mnesia calculate the continuation.
From: erlang-questions@REDACTED [erlang-questions@REDACTED] On Behalf Of Evans, Matthew [mevans@REDACTED]
Sent: Monday, June 15, 2009 10:42 AM
To: erlang-questions@REDACTED
Subject: [erlang-questions] Mnesia:select/4


I want to use mnesia:select/4 to select a limited range of records.

The Guard looks like:

Guard = [{'>=','$8',NPT}],

I can always place a lower limit on the guard, but not an upper limit. So my thought of using select/4, with a number of results of 1 should work (i.e. it'll return the next highest match).

My worry is how efficient is it if it'll produce lots of continuation data?

The access methods are dirty.



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