I do a lot of filtering on character values among massive data sets (millions of records). I know I can filter records with contains {[var1] contains 'Character string'} or with a position statement {position('charactervalue', [var1]) > 0}
Any idea on which one is more efficient? Is there a better way?
I'd have to say contains should be faster, sice the second approach requires two operations, but it will depend on the implementation of either.
How about LIKE? Or having a separate dictionary table, for each letter, all GUIDs of rows where it can be found?