New Features in Oracle Database 19c

  • Oracle Database supplied user accounts are now schema only accounts

Most of the Oracle Database supplied user accounts, except SYS and sample schemas are now schema only accounts, that is, these accounts are created without passwords. This prevents malicious users from logging into these accounts. You can assign passwords to these accounts whenever you want them to be authenticated. To find the status of an account, query the ACCOUNT_STATUS column of the DBA_USERS data dictionary view. If the account is schema (more...)

How to enable auto start/shutdown for Oracle Database 18c Express Edition

Oracle Database 18c Express Edition can be enabled for automatic startup and shutdown with the operating system. This will not only allow you not to worry about starting and stopping the database but it will also ensure that the database is properly shutdown before the machine is powered off. Enabling auto startup/shutdown is done via … Continue reading "How to enable auto start/shutdown for Oracle Database 18c Express Edition"

How to install Oracle Database 18c XE on Linux

The new version of the free Oracle Database edition, Oracle Database 18c Express Edition, just got released for Linux 64-bit. Getting started is really simple on Oracle Linux, basically a three step process of downloading the RPM file, installing it and then configuring the database. On other Red Hat  compatible Linux distributions you will also have … Continue reading "How to install Oracle Database 18c XE on Linux"

Oracle Database 18c Express Edition is Generally Available!

Oracle just released the new version of Oracle Database Express Edition (XE), a free edition of Oracle Database. This release means something special to me, as I have been closely involved in it and with the great team that brought us Oracle Database 18c XE. It has been 7 years since its predecessor, Oracle Database … Continue reading "Oracle Database 18c Express Edition is Generally Available!"

using AWR on Exadata

Oracle released a brand new Whitepaper for Exadata

How to use AWR Report on Exadata Machines

This Whitepaper gives details how the AWR reports can be used in conjunction with Exadata to monitor and analyze database performance issues

http://www.oracle.com/technetwork/database/availability/exadata-maa-best-practices-155385.html

 

 

 

ORAchk (EXAchk) und der Collection Manager (Teil 2)

Nun geht es mit Teil 2 weiter.

Nach dem nun die APEX Installation fertig ist, geht es darum den Collection Manager zu installieren und zu konfigurieren.

Dazu empfehle ich sich für das Setup parallel die Dokumentation, also das User’s Guide „Oracle® ORAchk and EXAchk“ und hier Kapitel 1.9 Oracle Health Check Collections Manager for Oracle“ zu öffnen.

Wir melden uns nun am Admin Service an:

 

http://o1:8080/apex/apex_admin

Der neue „Workspace“ wird erstellt. Im zweiten Schritt (more...)

ORAchk (EXAchk) und der Collection Manager (Teil 1)

ORAchk & EXAchk sind wichtige Tools im täglichen Oracle DBA Geschäft. Allerdings habe diese Tools wenn man Sie einmalig oder mehrfach startet den großen Nachteil das man jeweils einzelne Reports erhält und diese nicht miteinander vergleichen kann, oder eine Historie erhält. Es bedeutet im Umkehrschluss man muss sich selbst eine „Ordnung“ überlegen und die Verwaltung übernehmen.

Genau an diesem Punkt kommt nun der „Collection Manager“ ins Spiel, der eine komplette APEX Anwendung ist und die (more...)

DBMS_CLOUD Package – A Reference Guide

The Appendix A of the Using Oracle Autonomous Data Warehouse Cloud guide describes the DBMS_CLOUD package. Unfortunately, it documents only a subset of the subroutines. And, for some of them, the description could also be enhanced. Therefore, while I was testing all the subroutines the DBMS_CLOUD package provides, I took a number of notes. By the end of my tests, I got what I can call my personal reference guide to the package. Since it (more...)

Beware of loopback MTU size with RAC on Oracle Linux 7

I recently had to troubleshoot a hung instance in a 2 node RAC system. 4 months earlier, the system was reinstalled in a rolling fashion due to the requirement of Linux Upgrade from Oracle Linux 5 to Oracle Linux 7. This was required because of lack of certification for a storage migration to an AllFlash Storage. The system has been stable when running with Oracle Linux 5 for several years. Around 4 months after the (more...)

Patch Recommendations for Oracle Database 12cR1 and Cloud Control 13cR2

During my consulting engagements I see a lot of systems and many bugs. Most of the time, there is already a patch available to avoid the bug. I have collected all the recommended patches for the Oracle Database 12.1.0.2 (SE2 and EE) and Oracle Enterprise Manager 13cR2. This should help to avoid most critical known issues. Versions 12.2.0.1 and 18c will be added later this year.

Patch Recommendations

BAAS: Battle Against Archiver Stuck – ALTERNATE Archive Location

If you are managing volatile systems, you might have encountered Archiver-Stuck in the past.

0RA-00257:archiver error, connect internal only until freed
ORA-16014:log 2 sequence# 1789 not archived, no available destinations

If this is the case, you might be interested in a rarely used feature called “ALTERNATE Archive Locations”. This is a second independent archive log destination, that is only used in case the primary destination is failing (full). In that case, the dest_2 is automatically (more...)

Modifications to hidden parameters between 12.1.0.2 and 12.2.0.1

I recently troubleshooted an issue with RMAN catalog database using seperate schemas for each target database and more than 300 schemas present. Catalog Database was on 12.2.0.1 and suffering from severe mutex contention because of huge version counts for RMAN catalog SQL statements. I then realized that the default number of max child cursors was increased from 1024 to 8192 in 12.2.0.1. This made me check what other parameters (more...)

Oracle 18c – SQLPlus cute Features

As I got my fingers on the latest Oracle 18c Release, I had the chance to test some cute new features within SQLPlus, which are really helpful.

SET LINESIZE WINDOW:

The new option WINDOW for SET LINESIZE automatically adjust your linesize to your current window size.

As you can see in the below screenshot, the first select was executed without the linesize option, so you will have the usual line break in your result set. (more...)

Oracle 18c – ALTER USER RENAME

2 years ago, I have published an article series about the undocumented feature "ALTER USER RENAME":

As I was getting access to an Oracle 18c Database, I was trying directly, if the ALTER USER RENAME still works (more...)

Playing with 18c on Oracle Database Cloud Service – How to use and create a database STEP by STEP

  The Oracle Database Cloud Service (ODBCS)  is the DBaaS  extension of Virtual Image Service and includes additional automation for database provisioning during service creation, backup, recovery, and patching. While you are still responsible for the complete management of the environment,

Blocking Session not visible in v$ Views

I had to troubleshoot an issue on a company ERP systems database, where several sessions were waiting for ‘enq: TX row lock contention’. It was a table containing print server nodes and this caused no more printouts. Usually troubleshooting locking issues is quite straightforward in recent versions of oracle database, but this time, the column “v$session.blocking_session” was not populated and there was no entry in v$lock for the blocker. This was strange, so I (more...)

Why I picked Postgres over Oracle, part III

This is the final episode of this short series of blog posts on some of my drivers for moving to Postgres from Oracle.
Please do read Part I and Part II of the series if you have not done so. It discussed the topics “History”, “More recently”, “The switch to Postgres”, “Realization”, “Pricing”, “Support” and “Extensibility”.

In summary:

  • Part one focused on “why not Oracle anymore, so much”
  • Part two discussed on the comparison (more...)

Why I picked Postgres over Oracle, part II

Continuing this short series of blog posts on some of my drivers for moving to Postgres from Oracle.
Please do read Part I of the series if you have not done so. It discussed the topics “History”, “More recently” and “The switch to Postgres”.

Realization

In the last months, discussing Postgres with my Oracle peers, playing with the software and the tooling, I actually quite quickly realized Postgres is a lot cooler, at least to (more...)

How Well a Query Optimizer Handles Subqueries?

At the beginning of December, at the UKOUG Tech17 conference in Birmingham (GB), I presented a comparison of the query optimizers of MySQL 8.0.3 and PostgreSQL 10.1. One of the things I talked about is their ability to handle subqueries. I summarized my findings with the following sentence:

Simple sub-queries that are not correctly optimized were observed.

It goes without saying that such a sentence leaves a lot of questions open. After (more...)

Why I picked Postgres over Oracle, part I

As with many stories, if you have something to tell, it quickly takes up a lot of space. Therefor this will be a series of blog posts on Postgres and a bit of Oracle. It will be a short series, though…

Let’s begin

History

 I have started with databases quite early on in my career. RMS by Datapoint… was it really a database? Well, at least sort of. It held data in a central (more...)