The LOADFACTOR (or SPLITFACTOR) option applies to index random, index sequential, and ordered list sets and subsets. It governs the number of entries placed in the old and new tables when an existing table is split. Entries in index sequential and ordered list sets and subsets are ordered by key value. Index random sets and subset entries are ordered by folded key. These entries are grouped in tables. When entries are added to the set or subset, the structure is searched and the new entry is added to the appropriate table. If the table which is to hold the new entry is already full, a new table is created and some of the entries in the existing table are moved to the new one. The LOADFACTOR option determines, in part, the number of entries that are moved. Refer to Structure Formats for additional details concerning table splitting.

The default LOADFACTOR value for index sequential and ordered list structures is 66 percent. The default for index random structures is 50 percent. After a table is split, at least one entry must be present in each table; therefore, a LOADFACTOR value of 90 percent for a table with five entries is illegal. For example, if you take 90 percent and multiply it by 5, the result is 4.5, and this number falls below the requirement of one entry in each table.