Ah, maybe I wasn't quite clear enough.
What I meant was, is there any performance difference between:
CREATE INDEX ON my_table ( a , b , c )
and
CREATE INDEX ON my_table ( c , b , a )
I'm guessing not, presumably because the index is using some kind of hashing
but I thought I'd ask, just to be sure :-)
> Taka <sqlite-T/[EMAIL PROTECTED]> wrote:
>> Does it make a difference what order the columns are specified when
>> creating an index?
> Yes. An index on colums (a, b, c, d) can also speed up search on column
> a, on a pair of columns (a, b) and on a triple (a, b, c). If you have a
> query with a where clause looking like "where a=1 and b=2" the matching
> records will be found using the index. But if you have "where a=1 and
> c=2" then all records with a=1 will be found using the index, then a
> sequential scan through those records will be needed to find records
> matching c=2
> Igor Tandetnik
