2 days ago I gave a presentation “Oracle 12c from the attackers perspective” at the DOAG SIG Security. I learned some interesting things, especially that a fix for the Oracle oradebug “disable auditing” problem is available since 9 months.
Oradebug allows to run OS commands and to enable/disable Oracle SYSDBA (more...)
I have finished now my work on integrating last PMD version 5.0.5 into JDeveloper.
This is available now for JDeveloper 184.108.40.206 upwards, 11.1.2.x. and 12.1.2. There is no new functionality, as the most work intensive part was the rewriting for (more...)
Enterprise Manager Oracle Management Server (OMS) installations generate huge amounts of log and trace files under the covers these days, and although the logs are rotated out-of-the-box, they’re not automatically deleted. Over time (as I was reminded again today ), these logs can amount to a large portion of your (more...)
Do you know, that PMD can analyse XML files since version 5? Many of ADF files are XML configuration files – wouldn’t it be a good idea to create some static code analysis rules for ADF too?
Unfortunatly oracle configuration files in most times create references to dtd’s, which are (more...)
The TIMESTAMP WITH TIME ZONE data type that got introduced a long time ago is known for some oddities, for example Tony Hasler has a nice summary of some of them here
.Here is another oddity that shows up when trying to aggregate on such a data type. Have a look at the following simple example:
create table t
rownum as id
, date '2000-01-01' + rownum - 1 as some_date
, cast(date (more...)
Original Post can be viewed at portmap: unrecognized service on RHEL6
Quick note for people using NFS for shared storage on RAC database. Till RHEL5 we had to ensure nfs,nfslock and portmap service has to be running. These services are required otherwise you will get following errors while mounting database (more...)
A new major release (version 3.0) of my XPLAN_ASH tool is available for download.You can download the latest version here.
In addition to many changes to the way the information is presented and many other smaller changes to functionality there is one major new feature: XPLAN_ASH now also supports S-ASH
, the free ASH implementation.
If you run XPLAN_ASH in a S-ASH repository owner schema, it will automatically detect that and adjust accordingly. (more...)
Original Post can be viewed at cursor: pin S wait on X
Few weeks back thread came up on oracle-l freelist regarding ”cursor: pin S wait on X” event . Tanel Poder replied to this thread with excellent explanation. You can read full thread here
This wait happens when your (more...)
Install the Oracle Database Gateways 11g R2 (11.2). See the screen snapshots of the installation here.
- During the installation, the following default initialization parameter file is created:
dg4msql = Database gateway for Microsoft SQL Server.
If you choose a different database option, (more...)
Attention all data modellers - we are pleased to announce the release of SQL Developer Data Modeler 3.3. This release includes a new search, reports can be generated from search results, extended Excel import and export capabilities and more control and flexibility in generating your (more...)
In the previous post
I've demonstrated an unexpected Nested Loop Join caused by an extreme data distribution. Although unexpected at first sight, the performance of the execution plan selected by the optimizer is decent - provided the estimates are in the right ballpark.Here is another case of an unexpected execution plan, this time about Merge Joins
In order to appreciate why the execution plan encountered is unexpected, first a quick summary about (more...)
Recently I came across some interesting edge cases regarding the costing of joins. They all have in common that they result in (at first sight) unexpected execution plans, but only some of them are actual threats to performance.
The first one is about outer joins
with an extreme data distribution. Consider the following data setup:
create table t1
rownum as id
, rpad('x', 100) as filler
, case when rownum > (more...)
Oracle 10g introduced the QB_NAME
hint that can come handy in case hints need to be applied to more complex statements, in particular when possibly multiple layers of views / subqueries are involved.Jonathan Lewis has a older blog post
that describes more details.Just in case you wonder why sometimes apparently the QB_NAME
hint - along with all other hints that refer to the assigned query block name - seems to be ignored: One (more...)
See the blog post over at Oracle for details, and be sure to send Christopher Jones an email (via the address in his post) stating you're an active user of the client. As Christopher mentions in his post,
You can really help us justify resources for the OS X bundle if you email me letting me know you are a fan. Since Instant Client is a free download, it is tricky for us to know how widely it gets used.
Jump to OTN to download, but please remember to email Christopher as well, if you're interested in seeing the client (more...)
Original Post can be viewed at 11.2 AQ – Messages stuck in PROCESESED,WAIT State
I had been working today on AQ issue where messages were not moving from WAIT to READY State.This was on 220.127.116.11 database running on RHEL5u6(64 bit). I thought of quickly documenting it for easy reference When you enqueue record, you can specify delay after which record should be ready for dequeue. During this time, MSG_STATE [...]