Indexed Query examining too many rows!

[Cabbar Duzayak]

Hi All,

I have a table with a btree index on its searchKey column, and when I
send a simple query on this table:

explain select * from DataIndex where (searchKey like 'A%') order by
searchKey limit 10

rows is returning 59548 and it tells me that it is using the searchKey index.

Also, a select count(*) on this table returns 32104 rows, i.e.

select count(*) from DataIndex where searchKey like 'a%' -> gives
32104 as its result

Am I doing something wrong here? Given that the searched column is
indexed, shouldn't it examine way less rows?

Thanks.