This option is valid
only when CURSOR_TYPE=KEYSET_DRIVEN.
If KEYSET_SIZE=0, the
entire cursor is keyset-driven. If you specify a value greater than
0 for KEYSET_SIZE=, that value indicates the number of rows within
the cursor that functions as a keyset-driven cursor. When you scroll
beyond the bounds that KEYSET_SIZE= specifies, the cursor becomes
dynamic and new rows might be included in the cursor. This becomes
the new keyset, and the cursor functions as a keyset-driven cursor
again. Whenever you specify a value between 1 and the number of rows
in the cursor, the cursor is considered to be a mixed cursor: Part
of it functions as a keyset-driven cursor and part functions as a
dynamic cursor.