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19c

Creating a new disk group for use with ASM Filter Driver on the command line in Oracle 19c

In my previous post I shared my surprise when I learned that calling gridSetup.sh 19c for use with Oracle ASM Filter Driver (ASMFD) required me to specify the names of the native block devices. This is definitely different from installing ASM with ASMLib where you pass ASM disks as “ORCL:diskname” to the installer.

Um, that’s great, but why did I write this post? Well, once the installation/configuration steps are completed you most likely need to create at least a second disk group. In my case that’s going to be RECO, for use with the Fast Recovery Area (FRA). This post details the necessary steps to get there, as they are different compared to the initial call to gridSetup.sh.

Silent installation: Oracle Restart 19c, ASM Filter Driver, RHCK edition

As promised in the earlier post here are my notes about installing Oracle Restart 19c on Oracle Linux 7.7 using the RedHat compatible kernel (RHCK). Please consult the ACFS/ASMFD compatibility matrix, My Oracle Support DocID 1369107.1 for the latest information about ASMFD compatibility with various kernels as well.

Why am I starting the series with a seemingly “odd” kernel, at least from the point of view of Oracle Linux? If you try to install the Oracle Restart base release with UEK 5, you get strange error messages back from gridSetup telling you about invalid ASM disks. While that’s probably true, it’s a secondary error. The main cause of the problem is this:

Oracle 19c Automatic Indexing: Index Created But Not Actually Used (Because Your Young)

    The following is an interesting example of how Oracle Automatic Indexing is currently implemented that can result in an Automatic Index being created but ultimately ignored by the CBO. To illustrate, we begin by creating a simple little table that has two columns of particular interest, CODE2 which has 100 distinct values and […]

Oracle Restart 19c: silent installation and ASM Filter Driver

Oracle 19c is has been getting a lot of traction recently, and I have been researching various aspects around its installation and use. One topic that came up recently was the installation of Oracle Restart 19c using ASM Filter Driver. ASM Filter Driver has been around for a little while, but I never really looked at it closely. I found very little has been written about ASMFD in the context of Oracle 19c either, so I thought I’d revert the trend and write a series of posts about it (maybe I just didn’t find the relevant articles, I didn’t look too closely)

Tightened security in 20c

If you cannot wait for a fully autonomous offering, and you’ve jumped into the 20c preview release on Oracle Cloud, obviously the first thing you will probably be installing is Oracle Application Express.

Unlike autonomous, you’ll be installing it manually, which is a quick and easy process, and either in that installation or when adding ORDS later, you’ll be wanting to set the passwords for the public access accounts (typically APEX_PUBLIC_USER and APEX_REST_PUBLIC_USER).

Here’s what that looks like in Oracle Database 19c

18c versus 19c

I had someone say to me at an event recently: “We’re are going to upgrade to 18c, because 19c is new and is probably less stable”.

Let me sum up that sentiment simply: It’s Wrong Smile

Now, don’t get me wrong. I am not claiming that every Oracle release is perfect, contains zero bugs, never has a regression, will mow your lawn, take your kids to school, clean your house and sort out all the climate change issues in the world.

New Parallel Distribution Method For Direct Path Loads

Starting with version 12c Oracle obviously has introduced another parallel distribution method for direct path loads (applicable to INSERT APPEND and CTAS operations) when dealing with partitioned objects.

As you might already know, starting with version 11.2 Oracle supported a new variation of the PQ_DISTRIBUTE hint allowing more control how data gets distributed for the actual DML load step. In addition to the already documented methods (NONE, RANDOM / RANDOM_LOCAL, PARTITION) there is a new one EQUIPART which obviously only applies to scenarios where both, source and target table are equi partitioned.

Printing all table preferences affecting dbms_stats.gather_table_stats

Oracle 11g introduced the abilty to control the behaviour of the dbms_stats package by setting preferences on the database, schema, and table level. These affect the way dbms_stats goes about doing its work. This feature has been extensively documented, I found the post by Maria Colgan exceptionally good at explaining the mechanism.

Oracle Database 19c Automatic Indexing: Minimum Number Of Required Indexes (Low)

  As I discussed in my previous posts, Oracle Automatic Indexing will try and create as few indexes as possible to satisfy existing workloads, even if that means reordering the columns in an existing index. To illustrate how Automatic Indexing creates as few indexes as possible, I’ll create the following table which has a number […]

Initialising PL/SQL associative arrays in 18c and later

I can never remember how to initialise PL/SQL associative arrays and thought I’d write a short post about it. This is primarily based on an article on Oracle’s Ask Tom site, plus a little extra detail from Steven Feuerstein. Associative arrays were previously known as index-by tables, by the way.

Associative arrays before 18c

Prior to Oracle 18c, you had to initialise an associative array in a slightly cumbersome way, like so: