The title of this piece is the name given to a new feature in 188.8.131.52, and since I’ve recently blogged about a limitation of the in-memory option I thought I’d pick this feature as the next obvious thing to blog about. This is a bit of a non sequitur, though, as the feature seems to have nothing whatsoever to do with the in-memory option; instead it’s a cunning mechanism combining aspects of the star-transformation (but without the bitmap indexes), (more...)
Today I had a chance to install it in my lab and now I can start testing new OEM feature.
There is some documentation here and on Kellyn's blog.
It is not configured so first task is to (more...)
As I described in my previous post I had to migrate database from HP-UX into Linux and also upgrade it from 10g into 12c. This time it was only PoC (more...)
I keep hearing about “Center of Excellence”. The term makes no sense to me. What does it mean? The middle (center) of wonderfulness? A place (center) where one goes to become excellent? Lately I’ve been hearing it used to describe our lab which is just a collection of computer equipment. In our case it’s a bunch of Oracle Engineered Systems. Our lab is really cool because we have a bunch of bad ass toys. I (more...)
This graph represents commit time compared to CPU utilization and redo log write time. I’ve included only the hourly intervals with more than 1,000,000 commits. At these peaks the number of commits ranges 1 to 1.6 million commits per hour so each point on the graph represents roughly the same commit rate. I’m puzzled by why the commit time bounces around peaking above 5 milliseconds when I can’t see any peaks (more...)
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...)
SQL> alter table p_objects
2 add partition p201410
3 values less than (to_date('2014/11/01','yyyy/mm/dd'))
5 subpartition p201410_spdts values ('DTS')
Here’s a script to create a table, with index, and collect stats on it. Once I’ve collected stats I’ve checked the execution plan to discover that a hint has been ignored (for a well-known reason):
create table t2 as select mod(rownum,200) n1, mod(rownum,200) n2, rpad(rownum,180) v1 from all_objects where rownum <= 3000 ; create index t2_i1 on t2(n1); begin dbms_stats.gather_table_stats( user, 't2', method_opt => 'for all columns size 1' ); end; / explain plan for (more...)
OTN - Oracle Technology Network Latina America continue publish our articles. Our 7th technical article published on OTN in Portuguese Language at 20th August. This article entitled : Oracle Database 12c, O que acontece em um CDB quando um PDB tem ser recuperado written by Joel Perez (Oracle ACED), Mahir M. Quluzade (OCE) and Rodrigo Mufalini (Oracle ACE) .
It is a link of article: http://www.oracle.com/technetwork/pt/articles/database-performance/cdb-quando-pdb-tem-ser-recuperado-2270042-ptb.html
I wanted to expand on a thread in a LinkedIn group I’m part of, where one of the members wrote “It’s funny when 2 experts are arguing about who is better”, using Tom Kyte and Jonathan Lewis as examples of people they say are “Experts”.
Disclaimer: I have not spoken to Jonathan or Tom in regard to their viewpoints on this subject, so this shouldn’t be taken as them saying any of this, just my (more...)
I am learning about how well commits scale on Oracle 11.2 and so far they seem to scale surprisingly well.
I’ve looked at two waits – log file parallel write and log file sync. Based on documents I’ve read on Oracle’s support site log file parallel write represents the time it takes to do one write to the redo logs. For mirrored redo logs the log file parallel write time includes the (more...)
A couple of people have asked me recently about a classic problem that most DBAs know: how to view ASM trace files in the VIM editor when the filenames start with a + character. To my surprise, there are actually quite a few different ways of doing it. Since it’s come up, I thought I’d list a few of them here… If you have another one to add, feel free to comment. I know that (more...)
Download Document here
OTech Magazine - The independent magazine for Oracle professionals. Yesterday fourth issue of the OTech Magazine, the independent magazine for Oracle professionals published.
In this issue also included my article: Oracle Database 12c: Cross Platform Transport non-CDB to PDB using RMAN Backup Sets
You can download online OTech Magazine #4 Isssue - Summer 2014
We can create a PDB using upgraded database (non-CDB) and can be adopt the 12.1 non-CDB into (more...)
In case you haven’t noticed it – and chances are you haven’t noticed because I just created it! – I’ve added a new page called “Tips and Techniques” to the website. It’s where I keep a random collection of odd items I’ve come across that might be of interest yet don’t deserve a full blog post. It’s sort of like a FAQ list, but not necessarily with the “F”.
You can reach it either via (more...)
While 8k is the default block size, Oracle supports other block sizes, too. Smaller block sizes (more commonly, 4k) are encouraged for OLTP workloads to reduce concurrency, and even smaller block size, 2k, is recommended for databases running on “Advanced format” (or “4K”) storage. Oracle documentation warns us of possible implications when storing larger rows in 2k/4k blocks, such as potentially larger space overhead due to metadata, or even possibility of row chaining. What it (more...)
Let's take the following example:
SQL> select rid, sys_op_zone_id(rid) zone_id
4 select chartorowid('AAAS5KAAHAAABYDAAA') rid
5 from dual
Recalling that extended ROWID has the following format (a nice picture from Oracle Documentation):
In the binary format that would correspond to:
- Data Object Number -- 32 bits
- Relative File (more...)
Although last week we had a 3 node successfully upgrade track record, we encountered ASM upgrade troubles whilst running (more...)