Confusion and problems with lost+found directory in MySQL/Galera cluster configuration

The lost+found directory is filesystem directory created at root level of mounted drive for ext file systems. It is used by file system check tools (fsck) for file recoveries.

In MySql world it can cause confusion or possible problems with synchronisation in Galera cluster configuration.

Let’s check some examples.

I have MySQL database with datadir=/data in configuration file. I have deleted lost+found directory and restarted MySQL service.

When I list my databases this is result:


Analytische Funktionen (Teil 3): Gruppen mit zufälliger Auswahl der Datenbasis

Das folgende Beispiel bezieht sich auf die Datenbasis meines ersten Post zu "Analytischen Funktionen".
Es geht darum, dass für das Jahr 2014 drei Gruppen (mit einem Hash-Wert je Gruppe) gebildet werden müssen.
Gruppe 1:
- 3 zufällig ausgewählte Bundesländer die mit B anfangen
Gruppe 2:
- 3 zufällig ausgewählte Bundesländer die mit S anfangen
Gruppe 3:
- 3 zufällig ausgewählte Bundesländer die NICHT mit B und S anfangen

Hier das dafür notwendige SQL:

Why go to Oracle OpenWorld?

We’re a shade under a month away from the biggest event in the calendar for those that work in the Oracle marketplace – the Oracle OpenWorld Conference.

It runs every year in San Francisco and draws a massive 60,000 attendees from 145 countries (plus 2.1 million online attendees). That’s huge.

There are more than 2,500 sessions from ~3,600 speakers, approximately half of which are customers/partners and half are Oracle themselves. As well as the sessions there are (more...)

About downloading files from an Apex page without using download links

Always check out the original article at for latest comments, fixes and updates. Yesterday I needed to download a file as the final step in processing a user request involving a tabular form. For some reason this requirement is somewhat unusual if you look at the most typical scenarios where you either download files stored in a table by means of report links or a

AskTom and formatting

There’s an interesting “debate” going on under AskTom at the moment.  It’s hardly cause for major concern, but anyone is welcome to add their thoughts as comments to this blog post.  (Naturally, if your comments agree with my opinion, then that’s great.  If your comments don’t agree, then I’ll post them and ignore them Smile – ah the joys of being a blog owner)

So here’s the issue.  When we are posting (more...)

Zusammenspiel von log writer und foreground Prozessen beim Commit

Wenn Frits Hoogland, dessen Beiträge in der Regel ziemlich komplexe Analysen beinhalten, seinen Artikel How the log writer and foreground processes work together on commit mit den Worten beginnen lässt "warning: this is a rather detailed technical post on the internal working of the Oracle database’s commit interactions between the committing foreground processes and the log writer", dann sollte ich so einen Hinweis vielleicht lieber ernst nehmen. Nach der wiederholten Lektüre des Textes bin (more...)

Top 8 Strategies to Thrive at Oracle OpenWorld

Yes! It’s that time of the year again when we start planning for the premier Oracle OpenWorld. So let’s get right into it! Read more here – Top 8 Strategies to Thrive at Oracle OpenWorld . . . . . . Realted article – Advanced Sessions at Oracle OpenWorld 2015 . . .

The post Top 8 Strategies to Thrive at Oracle OpenWorld appeared first on VitalSoftTech.

ORDS Java heap space OutOfMemoryError

I recently ran into a problem with an Apex application running on ORDS on Tomcat. The application has a page with a custom tabular form (built using the apex_item package). When this page is submitted, the form values are stored in the "g_fxx" arrays (g_f01, g_f02, etc).

The problem was that when the number rows (and therefore the number of elements in the arrays) got too big, the server would respond with a HTTP 500 (more...)

Arise from the flashback ashes……

If you're read some of my older stories on this blog you'll know I've had some interesting battles with flashback over the past couple of years... don't get me wrong i think it's (arguably) the best feature introduced over the past 10 years (i'm talking about all the different flavours of flashback with that comment).

Today i hit a whole series of random errors discovered a minor  new (well new to me) syntax to a (more...)

Database system target in pending status for standby database in OEM 12c

That’s not really a problem but annoying issue I had with OEM 12c. Once a standby database is promoted, the database system for the same is showing as metric collections error OR Status Pending.

The standby database doesn’t need its own system since it will join the primary database system. The solution is to associate the standby database with the primary system and then remove the standby database system.

For example – we’ve got primary (more...)

All Flash Arrays: Where’s My Capacity? Effective, Usable and Raw Explained


What’s the most important attribute to consider when you want to buy a new storage system? More critical than performance, more interesting than power and cooling requirements, maybe even more important than price? Whether it’s an enterprise-class All Flash Array, a new drive for your laptop or just a USB flash key, the first question on anybody’s mind is usually: how big is it?

Yet surprisingly, at least when it comes to All Flash Arrays, (more...)

Fun with array fetch

I’ve lost track of the number of times I’ve worked with systems that didn’t run brilliantly because every database operation was the “row at a time” methodology.  Typically you see hundreds of routines (either in the database in PL/SQL) or further up the chain in C#, Java etc, and the “alarm bells” start ringing in my head when all of those routines are prefixed with “GET_” and the input parameter looks like a primary (more...)

A ShipIt at Oracle’s Mexico Development Center

Editor’s note: Our team participated in many of the Summer of Innovation events held by Laurie (@lsptahoe) and her team. Here’s a report from Luis (@lsgaleana) on the Mexico Development Center (MDC) ShipIt held in mid-August. Enjoy.

Oracle Mexico Development Center (MDC) has grown to bring together some 700 employees, and it continues to grow weekly. However, there is only a single point of entry for every non-employee person, the receptionist.

Every visitor that (more...)

Cloud Control : Some minor issues (fixed)

em-12cSince the upgrade to Cloud Control, we’ve been having a couple of issues, mostly around EMCLI.

Some of our databases use Service Guard, so you don’t know which node they are running on. Rather than having an agent per package, we have one on each node. One of my colleagues wrote a little script to check which node the instance is running on, and relocate it if it has moved. This (more...)

Database patching in 12c still required after DBCA is used to create a new database

Thanks to colleague Patrick Roozen I learned that there’s a tiny little flaw in Oracle databases 12c patch procedures when using DBUA (uupgrade) and DBCA (create custom database) when SPU/PSU/BP are installed on top of the base release. This is described by Mike Dietrich in his blog ( Oracle Support Note 2047990.1 called “DBUA 12c and” explains why DBUA does not call datapatch:
“The DBUA uses the “ -x” (more...)

El Crap-itan

In the comments from yesterday’s post, Jonathan Roden mentioned the release of El Capitan. At that point, I hadn’t even heard about it. :) Being the naive idiot I am, I jumped head long into it.

The download was about 3G, which didn’t take too long. The upgrade itself took quite a while. That included one failure. During the installation, the system rebooted, as it said it would, and I thought it was over, but it was (more...)


I’m a bit of a dinosaur when it comes to how long I’ve been using Oracle.  But you should never stop learning.  That’s why I’m participating in a cool OpenWorld session in a few weeks, all about the modern technologies and frameworks that can now be used to build awesome applications on top of the Oracle database.  Come along – you’ll see some exciting stuff.  This session is all about modern (more...)

Fundamentals of SQL Writeback in Dodeca

One of the features of Dodeca is read-write functionality to SQL databases.  We often get questions as to how to write data back to a relational database, so I thought I would post a quick blog entry for our customers to reference.

This example will use a simple table structure in SQL Server though the concepts are the same when using Oracle, DB2, and most other relational databases.  The example will use a simple Dodeca (more...)

IBM Bluemix – Specify only Liberty buildpack features you require

I am more often then not using spring boot applications on IBM Bluemix and most of what I need is packaged with the application from JPA or JDBC, drivers, Rest etc. Of course with IBM Bluemix we can specify which build pack we wish to use but by default for java applications LIberty is used.

When a stand-alone application is deployed, a default Liberty configuration is provided for the application. The default configuration enables the (more...)

Critical Background Processes in Oracle Database 12c

There are several background processes running when you start Oracle Database 12c instance. Here is an example from one of the instances.    ora_acms_bt9prod1  ora_lreg_bt9prod1 ora_p00w_bt9prod1  ora_aqpc_bt9prod1  ora_m000_bt9prod1  ora_p00x_bt9prod1  ora_asmb_bt9prod1  ora_mark_bt9prod1  ora_p00y_bt9prod1  ora_cjq0_bt9prod1  ora_mman_bt9prod1  ora_p00z_bt9prod1  ora_ckpt_bt9prod1  ora_mmnl_bt9prod1  ora_ping_bt9prod1  ora_dbrm_bt9prod1  ora_mmon_bt9prod1  ora_pmon_bt9prod1  ora_dbw0_bt9prod1  ora_o000_bt9prod1  ora_ppa6_bt9prod1  ora_dbw1_bt9prod1  ora_p000_bt9prod1  ora_ppa7_bt9prod1  ora_dbw2_bt9prod1  ora_p001_bt9prod1  ora_psp0_bt9prod1  ora_dbw3_bt9prod1  ora_p002_bt9prod1  ora_pxmn_bt9prod1  ora_dbw4_bt9prod1 […]