This guide walks through creating an Oracle 12cR2 container database with CREATE DATABASE, explains OMF vs non‑OMF options, details the catcdb.sql/perl changes, resolves common Perl module errors, compares 10g/11g syntax differences, and provides practical fixes such as blocksize adjustments.
This article explains Oracle's dynamic sampling feature, outlines typical scenarios such as temporary tables and complex filters, presents real CRM case studies with misestimated cardinalities, demonstrates step‑by‑step solutions using DBMS_STATS commands, and shows how 12c enhancements dramatically improve estimation accuracy for complex queries.
The article recounts a troubleshooting session where a 12c Oracle standby database failed to connect via TNS, presenting the ORA-12514 error, analyzing listener and tnsnames configurations, uncovering an outdated 11g ORACLE_HOME, and detailing the steps to switch homes and restart the listener to resolve the issue.
An in‑depth walkthrough of Oracle 12c R2 Sharding, covering its core concepts, architecture, environment setup across three virtual machines, detailed GSM and shard catalog configuration commands, test model, results, limitations, and troubleshooting tips for real‑world OLTP deployments.
This guide provides a comprehensive checklist and scripted procedure for safely downgrading Oracle Database 12c (Standard or Enterprise Edition) to prior releases such as 11.2.0.3, 11.2.0.2, or 11.1.0.7, covering prerequisites, command‑line steps, post‑downgrade validation, and common pitfalls.
This article walks through semi‑automated Oracle Data Guard deployment, when and how to use DG Broker, practical failover, switchover and archive‑recovery scenarios, Oracle 12c enhancements like Far Sync and VALIDATE, a real‑world standby query failure case, and using Data Guard for database migration.
This article explains Oracle 12c's key memory‑related enhancements—including the extended database cache (Smart Flash Cache), PGA aggregate limit, In‑Memory column store with compression, SIMD processing, temperature‑based replacement, and big‑table cache—detailing their parameters, operation, and monitoring methods for improved database performance.
This article explains the classic Oracle batch‑processing issue caused by inaccurate statistics on tables with sharply changing row counts, reviews traditional mitigation methods and their drawbacks, and introduces Oracle 12c's online statistics gathering for bulk‑load as an automated solution while noting its current limitations.
This article explores the major enhancements in Oracle 12c's optimizer, including session‑level statistics for global temporary tables, new DBMS_STATS reporting procedures, adaptive features, advanced join elimination methods, incremental and concurrent statistics collection, and automatic column‑group detection, providing practical guidance for DBAs and developers.
This guide walks through adding ASM disks, creating an ACFS filesystem, building a RAC database on it, generating read‑only and read‑write snapshots while running DML, and cloning a second database from those snapshots, including optional Data Guard usage for zero‑impact testing.
