Placement SSL
166 U929-J-Z125-9-76
MODE clause
⎧POINTER-ARRAY⎫
MODE IS ⎨ ⎬ ATTACHED TO OWNER
⎩LIST ⎭
This entry is not permitted in SYSTEM sets.
If a set occurrence population greater than zero has been specifie d for the set (see the
section “Specifying the size of the set occurrences of a set” on page 140), UDS/SQL sets
up all the tables of a set occurrence subsequent to the owner record when the owner record
is stored.
A table for which ATTACHED has been specified takes precedence over other tables in that
it is stored in the space immediately following the owner.
Even if the owner is a member of a set for which space has been reserved with the
PLACEMENT OPTIMIZATION clause, UDS/SQL takes into account the storage space
requirements for an associated ATTACHED table so that the owner record can be stored
contiguously with the table (see the section “PLACEMENT OPTIMIZATION” on page 165).
If zero has been specified as set occurrence population, UDS/SQL sets up a table when the
first member record is stored. In this case, ATTACHED results in UDS/SQL setting up the
table as close as possible to the owner record.
ATTACHED is thus a means of making the owner record and its associated table available
in one disk access, provided there is enough space for the table in the owner page.
A prerequisite is that the owner record type has not been define d with LOCATION MODE
IS CALC, as space reservation for member records and tables is not possible in hash areas.