Index fields order

[Andrey Kondakov]

Hi,

I have several tables that can grow to be very large with the time.

In each table 3 first fields that my primary key consists of are located in the following order:
field1 binary(16),
field2 smallint,
field3 datetime

while primary key is composed like this:

primary key(field3, field1, field2).

Is it possible that such order mismatch impacts on insert performance?

Thank you,

Andrey