hey,
i have a table with 200,000 records (won't change size anymore), with a varchar 150 (indexed) field in it, containing a specific string .
i want to add an integer field, name First_Letter_Of_String, which will numericly encode the first letter of each record,
e.g:
A=>1,B=>2,....,Z=>26

so if a record contains a field with a value "a test value",
the value of First_letter_of_string would be 1.

that way, when someone searches for "zebra" i will run the query:
"select * from table where first_letter_of_string=26 and string_field like 'zebra%';"

is this faster than the usual "select * from table where string_field like 'zebra%" ?

or does mysql do any key optimizations (which i expect from him :) so i won't have to make this optimization "patch" myself ?

thankl