B-tree Indexes on UROWID Columns for Heap- and Index-Organized Tables (235)

UROWID datatype columns can hold logical primary key-based rowids identifying
rows of index-organized tables. Oracle supports indexes on UROWID datatypes of a
heap- or index-organized table. The index supports equality predicates on UROWID
columns. For predicates other than equality or for ordering on UROWID datatype
columns, the index is not used.

在堆表及索引表的 UROWID 列上建立B樹索引
1. 資料型別為 UROWID 的列可以用於儲存根據主鍵生成的唯一標示索引組織錶行的rowid
2. Oracle 能夠在堆表及索引表的 UROWID
列上建立索引。只有當一個查詢中謂詞的條件為等於才能利用此種索引

[@more@]