Fujitsu UDS/SQL V2.5

Placement SSL

164 U929-J-Z125-9-76

Natural optimization

If the user does not influence the placement of data within a re alm by means of the DDL

and SSL, UDS/SQL physically stores the data in the chronologica l order in which it is

entered. Thus, at initial load time or later on when running unload or load programs, the user

can select the load sequence in such a manner that a compl ete set occurrence with all

associated tables is stored in contiguous pages. Unlike other optimization methods, natural

optimization is effective over several levels of hierarchy. This method is especially useful if

the user recognizes critical access paths. In this case, data must be sto red in the same

sequence as in the critical access path.

Example

Figure 41: Load sequence for natural optimization

In this example, the access behavior on the critical access path CUSTOMER, CUSTOMER-

ORDER, ITEM is improved by the specified load sequence. The emphasis has been placed

on the optimization of the CUSTOMER-ORDER, ITEM path.

CUSTOMER

CUSTOMER-

ORDERS

ITEM

MARTIN

256

210

102

WALKER

Iron

Radio

Razor

Battery

Radio

Transistor

Battery