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Addressing Rows Directly with the ROWID Datatype

For example, one byte of RAW data with bits 11001011 is displayed and entered as

CB.

LONG RAW data cannot be indexed, but RAW data can be indexed.

See Also: Oracle Database SQL Reference for restrictions on LONG and LONG RAW datatypes

Addressing Rows Directly with the ROWID Datatype

Every row in an Oracle Database table is assigned a ROWID that corresponds to the physical address of a row. If the row is too large to fit within a single data block, the ROWID identifies the initial row piece. Although ROWIDs are usually unique, different rows can have the same ROWID if they are in the same data block but in different clustered tables.

Each table in Oracle Database has a pseudocolumn named ROWID.

See Also: Oracle Database Concepts for general information about the ROWID pseudocolumn and the ROWID datatype

Extended ROWID Format

Oracle Database uses an extended ROWID format, which supports features such as table partitions, index partitions, and clusters.

The extended ROWID includes the following information:

Data object (segment) identifier

Datafile identifier

Block identifier

Row identifier

The data object identifier is an identification number that Oracle Database assigns to schema objects, such as nonpartitioned tables or partitions. For example:

SELECT DATA_OBJECT_ID FROM ALL_OBJECTS

WHERE OWNER = 'SCOTT' AND OBJECT_NAME = 'EMP_TAB';

This query returns the data object identifier for the EMP_TAB table in the SCOTT schema.

2-36 Oracle Database Application Developer's Guide - Fundamentals

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