Instance recovery is the process of applying records in the online redo log to data files to reconstruct changes made after the most recent checkpoint. Instance recovery occurs automatically when…

Typically, you manually start an instance, and then mount and open the database, making it available for users. You can use the SQL*Plus STARTUP command, Oracle Enterprise Manager (Enterprise Manager),…

The most crucial structure for recovery is the online redo log, which consists of two or more preallocated files that store changes to the database as they occur. The online…

A deadlock is a situation in which two or more users are waiting for data locked by each other. Deadlocks prevent some transactions from continuing to work. Oracle Database automatically…

The central set of read-only reference tables and views of each Oracle database is known collectively as the data dictionary. Overview of the Data Dictionary An important part of an…

Purpose: Use a constraint to define an integrity constraint—a rule that restricts the values in a database. The Oracle server uses constraints to prevent invalid data entry into tables. You…