On Mon, May 12, 2014 at 4:46 PM, Jan Slodicka <[email protected]> wrote:
> Sqlite LIKE optimization is described as follows: > A like pattern of the form "x LIKE 'abc%'" is changed into constraints > "x>='abc' AND x<'abd' AND x LIKE 'abc%'" > Actually, I would do something like: "x>='abc' AND x<'ab c ' || <CharacterUpperLimit> AND x LIKE 'abc%'" where <CharacterUpperLimit> is a string with a single character that is guaranteed to be greater than -and NOT equal to- any other character. For instance, if the encoding was single-byte ANSI it would be something like: "x>='abc' AND x<'ab c ' || Char(255) AND x LIKE 'abc%'" I understand that it is difficult to find the least greater character of a given character if you are unaware of the inner workings of a collation, but maybe finding a consistent upper limit for all characters in all possible collations is not impossible? -- Constantine _______________________________________________ sqlite-users mailing list [email protected] http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
