About Oracle's ROWID

Each row (tuple) of a table in an Oracle database has a ROWID, which is the detailed address of the data, and the location of a row's specific data can be quickly located by Rowid,oracle.

rowID can be divided into two kinds of physical rowid and logic rowid. The rowid in a normal heap table is a physical rowid, and the ROWID of an indexed organization table (IOT) is a logical rowid. Oracle provides a UROWID data type that supports both physical and logical rowid, with more physical rowid

The physical rowid is divided into two formats: Extended ROWID (extended rowid) and restricted rowid (restricted rowid). The limit rowID is primarily Oracle7 and its previous ROWID format, which is now no longer used, and is reserved for compatibility only. Physical ROWID are now generally referred to as extended ROWID formats .

The format of the ROWID is as follows: (a Base64-based encoding) composed of data_object_id#+rfile#+block#+row#

Data Object Number file number block number line number
Oooooo FFF bbbbbb RRR

It can be queried by SQL statements, or it can be used as a where condition to query other fields

About Oracle's ROWID