[sqlite] Possible substr() optimization?

[Bernardo Sulzbach]

> select * from tbl1 where substr(col1,1,1) in ('A','a') and col1 like 'a_c%';

Just adding to Igor's answer:
 col1 between 'a' and 'b' or col1 between 'A' and 'B'
if you need this case sensitive behavior