Linkage methods SSL
146 U929-J-Z125-9-76
Figure 33: Set occurrence stored as a pointer array
If a pointer array occupies more than one page, each page is connected by act-keys twice.
If ORDER IS SORTED INDEXED, the pointer array is provided with additional higher-
ranking table levels. Each higher-ranking level has the same structure as the lowest level,
but contains only the last table entry of the pages containing the next lower level. The PPPs
pointing to the member records are replaced by the act-key of the page where the table
entry originates (see page 228, figure 59).
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Moore
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Owner record DBTT Pointer array Member records
Beer
Cocoa
Milk
Primary
key
RSQ
+
PPP
Gin
Beer
Cocoa
Milk
Gin
.
.
. . .
.