By Franck Pachot . Oracle Error: ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below ORA-01152: file … was not restored from a sufficiently old backup ORA-01110: data file … This error is one of the most misunderstood recovery error. It can happen in different case but I have here a simple example to reproduce it, with some…
By Franck Pachot . In a previous post I started this series of “Recovery in the ☁” with the Oracle Autonomous database. My goal is to explain the recovery procedures, especially the Point-In-Time recovery procedures because there is often confusion, which I tried to clarify in What is a database backup (back to the basics). And the terms used in…
By Franck Pachot . I’ll start this series with the Oracle Autonomous database but my goal is to cover the Point In Time recovery for many managed databases in the major cloud providers. Because I’ve seen lot of confusion about database backups (see What is a database backup (back to the basics)). On one side, in a managed database, we…
By Franck Pachot . TL;DR: do not consider a dump (like PostgreSQL pg_dump or Oracle expdp) as a database backup do not consider that your backup is successful if you didn’t test recovery databases provide physical database backups, easy and safe to restore and recover to any point-in-time between first backup and point of failure managed databases provide an easy…
I’ve published a while ago a twitter thead on some Oracle recovery concepts. For those who are not following twitter, I’m putting the whole thread here: 🔴⏬ Here I start a thread about some Oracle Database concepts. We will see how far it goes - all questions/comments welcome. 🔴⏬ A database (or DBMS - database management system) stores (for short and long term)…
By Mouhamadou Diaw The Oracle Multitenant architecture came with Oracle 12c a few years ago. For people usually working with traditional Non-CDB database it might be confusing the first time to do Backup and Recovery with pluggable databases (PDBs) In this document we are trying to explain how to use RMAN backup and recovery in a multitenant environment for an…
When discussing with customers about PostgreSQL we often hear that they can do things in one database that they can not do in PostgreSQL. Most of the times this is not true and you actually can do it in PostgreSQL. Maybe not in exactly the same way but this is not surprising as PostgreSQL does implement features not in exactly…
In the last post I looked at how dbi services designs a PostgreSQL architecture based on the products of EnterpriseDB. In this post I’ll look at the same questions but using pure community tools. If you do not need vendor support and do trust the community for providing help and fixes this is another way to go. And usually you…
By Franck Pachot . There has been the announce that non-CDB is deprecated, and the reaction that CDB is not yet stable. Well. Let’s talk about the major issue I’ve encountered. Multitenant is there for consolidation. What is the major requirement of consolidation? It’s availability. If you put all your databases into one server and managed by one instance, then…
By Franck Pachot . When you load data in direct-path and have the NOLOGGING attribute set, you minimize redo generation, but you take the risk, in case of media recovery, to loose the data in the blocks that you’ve loaded. So you probably run a backup as soon as the load is done. But what happens if you have a…
By Franck Pachot . Do you remember last year, when 12c arrived with multitenant, David Hueber warned us about the fact that a single PDB can, under certain conditions, generate a complete system downtime? We are beta testers and opened a SR for that. Now one year later the first patchset is out and obviously I checked if the issue…
By Franck Pachot . While answering to a question on Oracle forum about NOLOGGING consequences, I provided a test case that deserves a bit more explanation. Nologging operations are good to generate minimal redo on bulk operations (direct-path inserts, index creation/rebuild). But in case we have to restore a backup that was made before the nologging operation, we loose data.…
