When to use the Oracle Database In-Memory option?

The application and usage of the Oracle Database In-Memory has been described by Pom Bleeksma in this post. Oracle Database In-Memory can result in huge improvement in application query performance. This post will answer the question: “what would be an optimal situation for using the Oracle Database In-Memory feature?” The most predictable answer for these kind of questions is “it depends”. It is advisable to consult an expert before investing in this feature since (more...)

Partitioned Clusters

In case you hadn’t noticed it, partitioning has finally reached clusters in 12c – specifically They’re limited to hash clusters with range partitioning, but it may be enough to encourage more people to use the technology. Here’s a simple example of the syntax:

create cluster pt_hash_cluster (
        id              number(8,0),
        d_date          date,
        small_vc        varchar2(8),
        padding         varchar2(100)
-- single table
hashkeys 10000
hash is id
size 700
partition by range (d_date) (
        partition  (more...)

Change unknown SYSMAN password on #EM12c

When I normally start work on a new EM 12c environment, I would request to have a userid created; however, I don’t have a userid in this environment and I need access EM 12c as SYSMAN.  Without knowing the password for SYSMAN, how can I access the EM 12c interface?  The short answer is that I can change the SYSMAN password from the OS where EM 12c is running.

Before changing the SYSMAN password (more...)

ORE now available for Multitenant (PDB) version of 12c

Oracle has released an update to their Oracle R Enterprise software. We now have ORE 1.4.1 and this seems to have been released on the past day or so.

Here are the links to the important stuff:

ORE 1.4.1 Release Note

ORE 1.4.1 User Guide

ORE 1.4.1 Installation Guide

ORE 1.4.1 Download page

One of the main features of this new release is that it (more...)

Adding additional agents to OEM12c

One question I get asked a lot is “how can I add additional agent software to OEM 12c”?  The answer is pretty easy; just download and apply to the software library.  Now what does that mean?  In this post, I’ll explain how to download additional agents for later deployments to other platforms.

After logging into OEM 12c, go to the Setup -> Extensibility -> Self Update (Image 1).

Image 1:








Group By Bug

This just in from OTN Database Forum – a surprising little bug with “group by elimination” exclusive to 12c.

alter session set nls_date_format='dd-Mon-yyyy hh24:mi:ss';

       /* optimizer_features_enable('')*/
       trunc (ts,'DD') ts1, sum(fieldb) fieldb
from (
        ts, max(fieldb) fieldb
  from (
  select trunc(sysdate) - 1/24 ts, 1 fieldb from dual
  union all
  select trunc(sysdate) - 2/24 ts, 2 fieldb from dual
  union all
  select trunc(sysdate) - 3/24 ts, 3 fieldb from dual
  union  (more...)

ADF EMG Audit Rules available on JDeveloper 12.1.3

I got a few questions from people why the ADF EMG Audit Rules are not available in JDeveloper 12.1.3. So there has been a new release of the ADF EMG Audit Rules. No new functionality is implemented this time, but the extension is now available for JDeveloper 12.1.3.

If you go to Help -> Check for Updates, tick the Open source and Partner Extensions checkbox and press Next: 

Select the ADF (more...)

My Speaking Schedule for Oracle Open World 2014

A quick post to let you know about the two presentations that I’ll be doing at Oracle Open World 2014.

Session ID:         UGF4482
Session Title:     “Getting Started with SQL Pattern Matching in Oracle Database 12c
Venue / Room:  Moscone South – 301
Date and Time:  9/28/14, 13:30 – 14:15

Session ID:          CON4493
Session Title:      “Regular Expressions (more...)

In-memory Consistency

A comment on one of my early blogs about the 12c in-memory database option asked how Oracle would deal with read-consistency. I came up with a couple of comments outlining the sort of thing I would look for in a solution, and this note is an outline on how I started to tackle the question – with a couple of the subsequent observations. The data is (nearly) the same as the data I generated for my previous article on the (more...)

Rolling Out-of-Place patching para Oracle Grid Infrastructure 12c y 11gR2: clonación en esteroides

Mi artículo más reciente para ToadWorld, dentro de una serie dedicada a aplicar patches con mínima suspensión del servicio. Ahora detallando cómo aplicar patches a Grid Infrastructure usando un Golden Image. Introduction to Attribute Clustering (The Division Bell)

One of the really cool new features introduced in is Attribute Clustering. This new table based attribute allows you to very easily cluster data in close physical proximity based on the content of specific columns. As I’ve discussed many times, indexes love table data that is physically clustered in a similar manner to the index […]

Integrated Application Heartbeat for Oracle GoldenGate

Over the last two weeks I’ve been working on a heartbeat monitoring solution for a client.  This is not the normal heartbeat solution provided by Oracle as described in note 1299679.1; yet very similar.  The approach that I configured is similar to a traditional heartbeat setup but uses the same extract and replicats already being used by the database/application.  For simplicity reasons, I like to call this approach an Integrated Application Heartbeat.

In order (more...)

Making the CDB Common User Without Using C## Prefix….

If you have done any play with the latest release of Oracle database 12c, you must have come across the concept of Common and Local users. I won’t rewrite what’s already there in the docs but for setting the context of the post, a Common user must be created with a prefix added to the username-C##. Miss that and you won’t be able to create one while being connected to the Container database. On (more...)

OTech Magazine – Summer 2014

OTech Magazine – Summer 2014

OTech magazineThe fourth issue of OTech Magazine, the independent magazine for Oracle professionals, is available. For the summer 2014 issue there are some more personal articles included. Titles vary from The Spiritual Programmer to The Next Generation: Oracle SOA Suite 12c and back via How to protect your sensitive data using Oracle Data Vault.

Download OTech Magazine – Summer 2014 here.


SOA Suite 12c: Configuring GMail as the inbound email provider for UMS (IMAP, SSL)

In a recent article, I discussed how to configure the SOA Suite 12c for sending emails using GMail: http://technology.amis.nl/2014/08/05/setup-gmail-as-mail-provider-for-soa-suite-12c-configure-smtp-certificate-in-trust-store/. An interesting aspect of that configuration is the loading of the GMail SSL certificate into the Keystore used by WebLogic, in order for the SSL based interaction with GMail to successfully be performed. The configuration of GMail for inbound interactions requires a similar procedure for the certificate for the imap.gmail.com server.

This (more...)

Scaling up Cardinality Estimates in

Topic: Counting the number of distinct values (NDV) for a table column has important applications in the database domain, ranging from query optimization to optimizing reports for large data warehouses. However the legacy SQL method of using SELECT COUNT (DISTINCT <COL>) can be very slow. This is a well known problem and Oracle provides a new function APPROX_COUNT_DISTINCT implemented with a new-generation algorithm to address this issue by providing (more...)

#GoldenGate Bound Recovery

Every once in awhile when I restart an extract, I see entries in the report file that reference “Bounded Recovery”.  What exactly is “Bounded Recovery”?

First, keep in mind that “Bounded Recovery” is only for Oracle databases!

Second, according to the documentation, “Bounded Recovery” is a component of the general extract checkpointing facility.  This component of the extract guarantees an efficient recovery after an extract stops for any reason, no matter how many uncommitted transactions (more...)

New in Oracle 12c: Querying an Associative Array in PL/SQL Programs

I was aware that up to Oracle 11g, a PL/SQL program wasn’t allowed use an associative array in a SQL statement. This is what happens when I try to do it.

SQL> drop table test_array purge;

Table dropped.

SQL> create table test_array as
  2  select level num_col from dual
  3  connect by level <= 10;

Table created.

SQL> select * from test_array;


10  (more...)

Oracle 12c Database In-Memory option generally available

On the 22nd of july, patchset for Oracle 12c database was made generally available for Linux x86-64 and Solaris.

This patchset includes the eagerly awaited In-memory option which promises an application transparent performance boost by using column-format data storage in memory.

Database In – Memory uses an In-Memory column store (IM column store), which is a new component of the Oracle Database System Global Area (SGA), called the In-Memory Area. Data (more...)

Snapshot Too Old 2014-07-30 19:54:00

Mi artículo más reciente para ToadWorld, dentro de una serie dedicada a aplicar patches con mínima suspensión del servicio.