I referred some reference from my favorite Tim Hall blog (ORACLE_BASE) A.Basic of optimizer statistics: – The optimizer cost model relies on statistics collected about the objects involved in a query, and the database and host where the query runs. Statistics are critical to the optimizer’s ability to pick the… Continue Reading Oracle 12c gather statistics oracle deep dive

Introduction This document will help to guide you for installation of Oracle 12cR1 RAC Flex cluster infrastructure on Virtual Box which is very popular because of shared storage simulation feature. Below is overall requirement in nut-shell. We need 3 servers for now.I will install RAC on First 2 servers and… Continue Reading Installation of Oracle 12c RAC Flex cluster infrastructure on Virtual Box

  A.Very useful method to upgrade 11gR2 to 12c using transportable=always Full transportable export/import is a new feature in Oracle Database 12c that greatly simplifies the process of database migration. Combining the ease of use of Oracle Data Pump with the performance of transportable tablespaces, full transportable export/import gives you the… Continue Reading EXPDP and IMPDP command reference 12c

This document will help you providing guideline to upgrade Oracle 11g RAC to Oracle 12c RAC clusterware  and Database . Author:-Saibal Ghosh https://www.linkedin.com/in/saibal-ghosh-ccsk-prince2-%C2%AE-469b0a7/ 1 Tasks Before Upgrade 1.1 Backup the Database: Before we start the upgrade, it is a best practice to backup the database, Oracle Cluster Registry (OCR) and… Continue Reading Upgrade of Oracle 11g RAC database to Oracle 12c RAC DBUA

Overview of New PULL method The original “push” process is based on image copies.With Oracle Database 12c, a “pull” (or restore) process is based on backup sets. A connection is first established with the source database. The auxiliary instance then retrieves the required database files from the source database as… Continue Reading Active RMAN duplicate clone 12c using section size and compress backupset

Oracle introduced PDB from 12c to minimize following drawbacks in 11g   In 11g,sometimes we need to create numerous databases in single host which resulted below side effects and eventually slowed down whole system. 1.Too many background processes. 2.High shared memory. 3.Many copies of oracle metadata. Now We will delve… Continue Reading CDB and PDB concepts in Oracle 12c

Introduction The next document will describe the steps to restore scenario for CDB and PDB using Data protector and RMAN 1.New SYSBACKUP privilege in RMAN 12c 1.1 create common user in CDB with sysbackup privilege. [oracle@rac1 ~]$ export ORACLE_SID=orcl1 [oracle@rac1 ~]$ sqlplus / as sysdba SQL*Plus: Release 12.1.0.2.0 Production on… Continue Reading Different restore and recovery scenario for PDB and CDB in Oracle 12c