I have the following problem:

Table with 1.5 million records, growing constantly.

One field that contains the integer 0 in 99% of the records and
different values for all other records.

Sometimes I need to update this field with something like

update MYTABLE set F = newvalue where F = oldvalue


If I don't have an index, update is very slow. But having an index on
a field where a lot of records are the same, slows down the insert of
new records.

What is the best solution for this problem?

cu Christian