How to manage undo data?

Undo is copy of original, premodified data. Its captured for every transaction that changes data. Capturing undo data enables us to ROLLBACK uncommitted data.Undo supports  read consistent and flashback queries. Undo can rewind transactions and tables.Read consistent queries provide results that are consistent with data as of time query started. For read consistent query to Read More

BackupA

How to take RMAN backup?

RMAN is the component of oracle database that is used to perform backup and recovery operations.It can make consistent and inconsistent backups, perform incremental and full backups ,backup either whole database or portion of it. RMAN has its own scripting language and has interface with many popular backup software solutions. An Oracle database to which Read More

buffer

How to tune database buffer cache?

  Mechanism of database buffer cache: Before tuning lets understand the mechanism of database buffer cache.Database buffer cache is portion of SGA that holds block images read from data files.All users who are concurrently connected to the instance share access to database buffer cache. When user requires particular piece of data,it searches for the data Read More

sp

How to generate Statspack reports in Oracle?

Basically statspack report is similar to trace reports.Both have same purpose to find time consuming operations on a database. Set of commands to generate statspack reports: source set(tab button) sqlplus (db username/password) > exec statspack.snap;  –(start snap) Run your procedure or set of transactions. >exec statspack.snap; –(end snap) to view list of all snaps exec below command  Read More