Korrigierte Histogramm-Statistiken im SQL Server anlegen

Nachdem ich viele Jahre lang Tom Kytes Mantra wiederholt habe, dass alle RDBMS unterschiedlich sind und man die Unterschiede kennen muss, um sinnvoll mit den Systemen umzugehen, behaupte ich in jüngerer Vergangenheit immer häufiger, dass die relationalen Datenbanken im Prinzip alle ziemlich ähnlich sind und sich in mancher Hinsicht immer ähnlicher werden. In jedem Fall bin ich immer wieder froh, wenn ich neue Gemeinsamkeiten feststelle, so etwa auch diese hier: im immer wieder lesenswerten SQL (more...)

What’s new in Forms 12c, part 2

Let's now look into the Form Builder and what changes we got there.

First we see the facelift in the Open-Dialog. It's now the typical Windows-Dialog, where you have much more flexibility.

New features in the Convert-Dialog:

  • New Feature "Converting to and from XML"
  • Checkbox "Overwrite"
  • Checkbox "Keep window open", if you have to convert many files at once.

Preferences-Dialog, Tab "General":

  • The checkbox "Hide PL/SQL Compile Dialog" is new
  • Web Browser location (Forms 11g: (more...)

SQL Developer 4.1.2: Missing MSVCR100.dll file

I downloaded the latest version of SQL Developer (4.1.2) to a just-provisioned, pristine server running Windows Server 2012 R2.

I downloaded sqldeveloper-, unzipped it, and placed it under c:program filessqldeveloper- I double-clicked the main sqldeveloper executable and expected it to "just work" (as it usually does), but this time it didn't.

I got the following error message:

sqldeveloper64W.exe - System Error

The (more...)

Oracle Forms is heading to the clouds and to UK!

As I have been preaching from my soapbox for years now, Oracle Forms will remain a constant, supported development tool to build on premise, enterprise level, data entry desktop applications. However this time, Oracle has joined me by declaring their commitment to Oracle Forms, as Oracle Forms 12c was released on the heels of OOW. Oracle Forms 12c can be downloaded here. Our customers and team have been anticipating Oracle Forms 12c, and it is great to finally have it available.

It’s (more...)

Apex 5 Application Context

"under the hood"Just a quick note that (as mentioned by Christian Neumueller earlier) Apex 5 now populates an Application Context APEX$SESSION with the session’s User, Session ID and Workspace ID:


Using the above should be faster in your queries than calling v() to get these values. Note that the alias 'SESSION' won’t work like it does with v().

The context is managed by the database package APEX_050000.WWV_FLOW_SESSION_CONTEXT which is an undocumented (more...)

Ein griffiges Beispiel für Lateral Inline Views

Auf den Lateral Join, der in 12c eingeführt wurde, habe ich hier schon vor geraumer Zeit hingewiesen - aber was damals fehlte, war ein griffiges Beispiel dafür, was man damit eigentlich anstellen kann. Das hat nun Oren Nakdimon in Teil 7 seiner überaus lesenswerten Serie Write Less with More ergänzt. In seinem Beispiel wird eine Projekt-Tabelle mit einer last_days_to_show_in_reports Spalte vorgestellt, in der für die einzelnen Einträge unterschiedliche Zeiträume angegeben sind (als Anzahl von Tagen). (more...)

APEX 5.1: features shown at DOAG

On the last day of the DOAG conference, in the last time slot Patrick Wolf from the APEX development team did a session on the next release of APEX.
For the developer the most significant change in the Page Designer is the component view. This will be a tab in the center pane instead of a completely separate page.

Most time was spent showing the new Interactive Grid. The Interactive Grid will be a, loosly (more...)

Tech Tip: Connect to Snowflake db using #SQLDevModeler

So, some of you may have noticed that I took “real” job this week. I am now the Senior Technical Evangelist for a cool startup company called Snowflake Computing. Basically we provide a data warehouse database as a service in the cloud. Pretty cool stuff. (If you want to know more, check out our site […]

Ein Wait Interface für Postgres

Ein schöner Hinweis im Artikel Wait interface in PostgreSQL, dessen Autor ich leider nicht ohne weitere Recherche namentlich benennen kann: für postgres 9.4 gibt es eine von Ildus Kurbangaliev entwickelte Erweiterung pg_stat_wait, die möglicherweise in 9.6 Teil des Standards werden wird (aktuell aber noch ein Recompile von postgres und eine Einbindung via shared_preload_libraries erfordert). Nach der Installation stehen diverse Funktionen und Views zur Verfügung, die Informationen zu Events unterschiedlicher Typen bereitstellen (LWLocks, (more...)

How to change apex_public_user password in ORDS

When you install Oracle REST Data Services (ORDS) as the gateway for your Oracle Application Express (APEX) applications, you run the java -jar ords.war command to configure ORDS, including specifying connection strings and passwords for the service accounts apex_public_user, apex_listener and apex_rest_public_user.

The first time you run this command, you get asked where to store the configuration. A file called defaults.xml gets created in the folder you specify. It looks like this:


Wait Event Analyse mit Flame Graphs

Luca Canali hat im Databases at CERN Blog wieder einmal eine detaillierte Analyse vorgestellt, in der er Flame Graphs mit Extended Stack Profiling verbindet und damit die Aussagen des Oracle Wait Interfaces näher beleuchtet. Der eigentliche Anlass der Untersuchung ist dabei die Beobachtung des Auftretens von Fällen, in denen die DB time größer ist als die Summe von CPU time und Wait time, was a) nicht vorkommen sollte und b) mit dem Einsatz moderner Storage (more...)

Detect Empty List

You have a Select List item on your page driven from a dynamic query, e.g. one that only shows valid values. One day, users notice that the list appears empty and raise a defect note.


You check the query behind the list and verify that indeed, the list should be empty because there are no valid values to show. It’s an optional item so the user is free to save the record if they (more...)

Did it really fix it 2: Plan flip, unprofileable, baseline OFE round 2 and “stability”

Snappy title, huh?

Aka: Why a sql plan baseline may be no guarantee of stability.

The other day, a problematic plan flip…

Tangent 1:
Cue much discussion about plan flips etc.
My thoughts on stability are that the priority for most application owners is stability and predictability but that does not tally with the defaul CBO behaviour and potentially you have to turn off a helluva lot to even get close.

Tangent 2:
I have (more...)

Did it really fix it 1: OFE & nasty FIRST_ROWS plan on

Plan degradations on upgrade are normal.

This one’s no different.

On further investigation, turned out application was setting optimizer_mode = first_rows somewhere.

First point about this is that first_rows really shouldn’t be used either as a hint or as an optimizer_mode.

What does FIRST_ROWS mean?
From 11g doco:

The optimizer uses a mix of costs and heuristics to find a best plan for fast delivery of the first few rows.

If any sort of (more...)

Wanted: RDBMS superpower summary for app developers

At last night's WWCode Cincinnati panel, I recommended that developers talk to their DBA about what advanced capabilities their RDBMS can offer, so that they don't end up reimplementing functionality in the app that are already available (better and more efficiently) in the database itself. Devs can waste a lot of effort by thinking of databases as dumb, inert data boxes.

I was asked an excellent question: "Where can a dev quickly familiarize herself with (more...)

Media player in Apex

Quite a long time ago I made a collection of MP3s available from our Apex website and made them playable within the browser using Google’s shockwave player, using code like this:

<embed type="application/x-shockwave-flash"

This relies on the user’s browser being able to run flash applications. It looked like this:

With HTML5, however, this is no longer required, so I’ve updated it to:

<audio controls preload>
  <source src="#FILE_URL#" type="audio/mpeg">

Oracle OpenWorld 2015: The Developer’s Overview

Last week was Oracle OpenWorld in San Francisco, California, and a huge week for me and our whole team at AuraPlayer.  Our week began on Sunday when I presented my “Mobile / Cloud Buzz Words for Dummies” to over 120 people eager learn how to start their mobile journey. But in fact they weren’t! I was shocked to find out, by a show of hands, that only 3 people in a room of over (more...)

Integrating GitHub with Oracle Developer Cloud Service by Stefano La Porta

Stefano Illustrates how to integrate your existing repository in GitHub with Oracle Developer Cloud Service using you're preferred Git client or IDE that supports Git integration. Check out Stefano's entry here.

Better Data Modeling: What is #DataVault 2.0 and Why do I care?

Have you heard? Dan Linstedt has just had his new book published on Data Vault 2.0. It is called Building a Scalable Data Warehouse with Data Vault 2.0. If you are at all into data warehousing and agile design, you need to get this book now. So click here and be done. For those of […]

Apex 5 right side column

The new Universal Theme in Apex 5 includes a nice "right side column" feature that adds a sliding menu on the right side of the page, where you can place additional content, such as (for example) an audit trail, actions/links, comments, whatever.

Let me show you with a picture:

To add this to your page, simply change the page template to "Right Side Column", and note that a "Right Column" template position appears in the (more...)