I am slightly disappointed to report that the new extended data types cannot be used in the clustered tables. CLOB columns have never been allowed, and are still not allowed in 12c, but I expected the new data types to pass seamlessly. That is not the case:
SQL> create cluster testclu(intkey number(30,0));
SQL> create index testclu_ind on cluster testclu;
Now, let’s create a normal table (more...)
Here is the sqlplus scripting I use to check whether row chaining is degrading a query’s performance:
VARIABLE monitored_sid number;
SELECT sid into :monitored_sid
select b.value "table fetch continued rows"
where b.SID = :monitored_sid
and b.STATISTIC# = (SELECT STATISTIC# FROM V$STATNAME
WHERE NAME='table fetch continued row');
I create a test script with the problem query and put this code after it to (more...)
I received this error message in the following scenario:
– Connect to CDB
SQL> conn / as sysdba
– Start a transaction
SQL> create table test(c number);
insert into test values(1) ;
– Change the container to PDB without completing the transaction
SQL> alter session set container=pdb2;
– Try to shutdown the pluggable database
– It causes ORA-65023 because on switching the container (not making a connection to (more...)
photo by Jesus Solana
DBAs were cutting edge once upon a time. DBAs protected the company jewels and made sure the company’s data was secure, fast and dependable. DBAs discovered new ways to tune databases, exposed how internals worked, architected and proved optimal database designs. Now that so much information and knowledge has been created , documented, and automated, it seems that DBA work is becoming more and more commoditized. The DBA use to be (more...)
Bobby Durrett just put together a great little post on “outer joins : where do I put the (+)“.
I also have hard time remembering, and below is my cheat sheet using graphics.
If English and French both have a unique key on the “ordinal_id” then it’s basically one-to-one relationship
We add an arrow in the middle of the line to denote “outer join”. The arrow points from the table that drives (more...)
Today is the second anniversary of my first post on this blog.
Some time ago I played with a free blog that came with a yahoo email account that my wife and I share but didn’t get very far with that. Finally for this blog I decided to spend a small amount of money to get my own hosting and domain name.
I’m using iPage for the hosting. I’ve been happy with their (more...)
Application developers frequently experiment to achieve higher quality builds, they try things out, make mistakes and find fixes. Database design can be like that too, but rapidly changing the schema in traditional shared environment tends to break the application.
In this webinar, Kyle Hailey will explore how different types of cloning technology work and their benefits and limitations. The webinar will also demonstrate how you can setup and coordinate risk-free database experiments using Delphix and (more...)
Super Charge Database Deployments
Delphix and Pure Storage, a combination like chocolate and peanut butter.
I’m trying to get up to speed on 12c, especially the multitentant features. So, I decided to read the sections of the manuals that related to using multitentant. Here is the name of the manual I was looking at:
Oracle® Database Administrator’s Guide 12c Release 1 (12.1)
It isn’t great reading. It is kind of slow-paced and really more of a reference but since it is a large new feature I (more...)
At Fishbowl Solutions; we’ve been looking at ways to enhance and bring the Android experience closer to that native experience that every user wants: – here are some solutions that we are using today to help bridge the Android <4.4 gap and also bring in the latest web technology like WebSocket and WebRTC support not available with either cordova or ADF Mobile today..
When it comes to mobile development with ADF-Mobile or Cordova (HTML5) (more...)
Saw this blog post about how Cary Millsap learned about Oracle performance tuning and I thought it was interesting:
It is interesting because I’ve learned so much from Cary Millsap and Jeff Holt’s book and it is cool to see how Cary got to the position he is in as a well-known Oracle performance expert. I guess I’ve always found the performance tuning part of my Oracle DBA job the (more...)
In an earlier post about how query high compression eliminated row chaining in tables with more than 255 columns I got question about whether updates to tables with more than 255 columns and query high compression ran slower with this type of compression than on an uncompressed table.
The answer is that, at least in the tests I ran, the updates of a table with more than 255 columns took much longer on a table (more...)
I was on call again last week and again had to do a database recovery using RMAN. I thought I might as well document some lessons learned even though it went quite smoothly.
First, here are the steps I took. I’ve modified the commands and script so that our real usernames, passwords, database names, and host names are obscured, but otherwise it is exactly what I ran.
Environment wise we are on 11. (more...)
Do any of you use (or plan to use) VirtualBox on a MacBook Pro? If so, be warned that there are some bug reports claiming instability or poor performance of some VMs. In my case, I wanted to use 2 CPUs in my Linux/Oracle VM; when I did, some Oracle tests ran twice as slow […]
Interested in talking face to face about Delphix in NYC? Drop me a line. I’ll be in NYC on March 12th and 13th and look forward to meeting folks who are excited to learn more about Delphix.
New York Oracle’s User Group (NYOUG) is meeting March 12 and I will be speaking in the morning about the Agile Data Revolution. The cornerstone of the Agile Data Revolution is instant database duplication (more...)
Here is a small example.
Download the following file: W-ASH (web enabled ASH, file is wash.tar.gz )
Source is also on github at https://github.com/khailey/wash
Go to your apache web (more...)
The SYSBACKUP connectivity problems described in the previous post are caused by unpublished bug 15828768.
There is a way to connect, using SYSBACKUP privilege:
RMAN> connect target ‘system@local as sysbackup’
target database Password:
connected to target database: ORA12C (DBID=214280212, not open)
Please, note the quotes around the connection string. Without the quotes, this will not work. It works with both single and double quotes:
RMAN> connect target “system@local as sysbackup”
target database Password:
Oracle 12c has a great new privilege, tailor made for the paranoid oracle DBA guys like me. However, there are still some quirks: SYSBACKUP privilege doesn’t work over Oracle*Net. If the authentication method is SID based local authentication, all is well:
Oracle Database 12c Enterprise Edition Release 126.96.36.199.0 – 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
SQL> shutdown immediate