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Oracle database cleanup process after DROP DATABASE command - complete removal checklist

Complete Oracle Database Cleanup Checklist: Remove CDB After DROP DATABASE

Posted on by sanjeeva

Two weeks ago, I dropped a development CDB called TESTCDB on one of our lab servers. The DROP DATABASE command worked perfectly—but that was just the beginning. The server was still littered with configuration files, diagnostic logs, and startup scripts pointing to a database that no longer existed. If you’ve ever run DROP DATABASE INCLUDING Read more about Complete Oracle Database Cleanup Checklist: Remove CDB After DROP DATABASE[…]

Oracle CDB architecture showing pluggable database DATAPDB being dropped with datafiles - Oracle 19c multitenant illustration

How to Drop a Pluggable Database Including Datafiles in Oracle 19c

Posted on by sanjeeva

Last month, I needed to decommission a development PDB that was consuming valuable storage on our production CDB. The challenge? Ensuring all datafiles were completely removed without affecting other PDBs in the container. If you’ve ever hesitated before dropping a PDB—worried about orphaned datafiles or accidentally keeping files you meant to delete—this guide walks you Read more about How to Drop a Pluggable Database Including Datafiles in Oracle 19c[…]

ORA-01017 invalid username password error showing Oracle authentication architecture, password hashing versions, and troubleshooting workflow for Oracle 19c/21c databases

ORA-01017: Invalid Username/Password – Complete Guide

Posted on by sanjeeva

Last Updated: December 2025 | Oracle 19c/21c | By Ahaaryo Oracle Version Scope: This guide covers Oracle 19c (fully supported) and Oracle 21c (Innovation Release, already desupported but widely deployed). Introduction “The password is definitely correct!” – Every DBA has said this at least once while troubleshooting ORA-01017 invalid username password. I remember a production Read more about ORA-01017: Invalid Username/Password – Complete Guide[…]

DBA_HIST_ACTIVE_SESS_HISTORY Oracle ASH analysis dashboard showing SQL performance and wait events

DBA_HIST_ACTIVE_SESS_HISTORY: Complete Guide to Oracle ASH Analysis

Posted on by sanjeeva

Introduction Have you ever been asked to explain why your Oracle database was slow last Tuesday at 2:30 PM? Or needed to identify which SQL statements were causing CPU spikes during last night’s batch run? This is where DBA_HIST_ACTIVE_SESS_HISTORY becomes your most powerful diagnostic tool. Recently, we faced a production issue where users reported intermittent Read more about DBA_HIST_ACTIVE_SESS_HISTORY: Complete Guide to Oracle ASH Analysis[…]

Migrating Oracle 19c Database from Local Storage to ASM: A Complete Step-by-Step Guide

Posted on by sanjeeva

Last Updated: December 2025 | Oracle 19c | ASM Grid Infrastructure Have you ever encountered a frustrating situation where your Oracle database is running on local storage, and you need to migrate everything to ASM (Automatic Storage Management) without significant downtime? Recently, we faced this exact scenario with a production Oracle 19c Container Database (CDB) Read more about Migrating Oracle 19c Database from Local Storage to ASM: A Complete Step-by-Step Guide[…]

How to Enable Archive Log Mode in Oracle 19c (Complete Guide)

Posted on by sanjeeva

Introduction Need to enable archive log mode in Oracle 19c but unsure of the exact steps? Converting from NOARCHIVELOG to ARCHIVELOG mode is essential for production databases, yet many DBAs hesitate due to concerns about downtime and configuration complexity. In this guide, I’ll walk through the complete process of enabling archive log mode in Oracle Read more about How to Enable Archive Log Mode in Oracle 19c (Complete Guide)[…]