In select, delete, and update statements

You can use lru or mru (fetch-and-discard) in a select, delete, or update command to specify the I/O size for the query:

select select_list
      from table_name
           (index index_name prefetch size [lru|mru])
           [, table_name ...]
where ...

delete table_name from table_name (index index_name 
      prefetch size [lru|mru]) ... 

update table_name set col_name = value
      from table_name (index index_name
             prefetch size [lru|mru]) ...

This query adds the LRU replacement strategy to the 16K I/O specification:

select au_lname, au_fname, phone
    from authors (index au_names prefetch 16 lru)

For more information about specifying a prefetch size, see “Specifying I/O size in a query”.