When the number of values is within 256, a 1-Byte FP index is created. The FP index starts with this form.The actual key value of each row is stored in the lookup table and the FP entry (lookup key) contains the index into the lookup table. For a 1-Byte FP index, each FP entry occupies 1 byte.
With default main cache setting of 32 MB and a default FP_LOOKUP_SIZE_PPM setting of 2500, adding a new distinct value via LOAD, INSERT, or UPDATE to a FP(1) column of char(2), binary(2), or small integer, converts FP(1) to flat FP.
