On 2/9/16, Peter Aronson <pbaronson at att.net> wrote:
> So, why *isn't* metadata preserved between function calls for data values?
Because the database value will likely change, rendering the metadata
obsolete. The metadata is only preserved when the value is a
constant.
That mechanism is intended for operators like
x REGEXP 'pattern'
For regular expression processing, one typically compiles the regular
expression into byte-code, then runs the compiled regular expression
against a string to see if it matches. The meta-data is the compiled
byte-code. But that code is only valid as long as the pattern does
not change.
--
D. Richard Hipp
drh at sqlite.org
