May 2017

Quantum Space

Here’s a not very serious note that makes a serious point.  I’ve got a small tablespace made up of 4 files, and here’s a little report I can run against the data dictionary for that tablespace:


select 'File space' What, nvl(sum(user_bytes)/1048576,0) MB from dba_data_files where tablespace_name = 'LOB_TEST'
union all
select 'Free space',      nvl(sum(bytes/1048576),0)         from dba_free_space where tablespace_name = 'LOB_TEST'
union all
select 'Extents',         nvl(sum(bytes/1048576),0)         from dba_extents    where tablespace_name = 'LOB_TEST'
union all
select 'Segments',        nvl(sum(bytes/1048576),0)         from dba_segments   where tablespace_name = 'LOB_TEST'
;

The name of the tablespace isn’t significant – it happens to be a tablespace I created to do some tests relating to space allocation with securefile LOBs, and it’s been hanging around ever since.

Extending Codemonth search to include Oracle Text fuzzy and stem searches

My previous entry showed how the contains operator of Oracle Text made it possible to build a search function
for my website. It was a basic text search with no additional capability. For quick recap of how the query looked,
this is what I could run to search the description of my projects for the word package.

Announcing SLOB 2.4! Integrated Short Scans and Cloud (DBaaS) Support, and More.

This is a post announcing the release of SLOB 2.4!

VERSION

SLOB 2.4.0. Release notes (PDF): Click Here.

WHERE TO GET THE BITS

As always, please visit the SLOB Resources page. Click Here.

Its All About the DevOps Roll of the Dice

Different combination in the game of tech create a winning roll of the dice and other times create a loss.  Better communication between teams can offer a better opportunity to deter from holes in development cycle tools, especially when DevOps is the solution you’re striving for.

What is in a transportable tablespace dumpfile?

On 31st of May in Düsseldorf, at DOAG Datenbank, I’ll talk about transportable tablespaces and pluggable databases. Both methods are transporting data physically, the difference is in the transport of the metadata, which can be more flexible when transported logically, as with TTS, but faster when transported physically with PDB. I have a lot of demos to show transportable tablespaces with RMAN, and the different cloning features available in 12cR2. If I have time I’ll show what is inside the dumpfile when using Data Pump to export the metadata. Here is the idea.

expdp transport_tablespaces

Here is how we export metadata with Data Pump for transportable tablespaces.

Oracle text and implementing codemonth website search

I promised on the ODTUG codetalk series to implement search on the codemonth website. So this entry is a short description of the first steps I
have done to add simple search capability to the site.

Oracle Security 12cR2 and Oracle Security Training Dates

I am going to be teaching my two day class "How to perform a security audit of an Oracle database" in Athens, Greece on the 30th and 31st May 2017. This is advertised on Oracle University website and you can....[Read More]

Posted by Pete On 08/05/17 At 03:51 PM

opt_estimate

The opt_estimate hint is one of many that shouldn’t be used in end-user code and isn’t officially documented. Nevertheless – like so many other hints – it’s a hint that is hard to ignore when you see it floating around the code generated by the Oracle software. This note is prompted by a twitter question from fellow Oak Table member Stefan Koehler asking the about working of the hint’s index_filter parameter. Checking my library I knew the answer was yes – so after a quick exchange on twitter I said I’d write up a short note about my example, and this is it.

Can you open PDB$SEED read write?

If you are in multitenant, you probably already felt the desire to open the PDB$SEED in READ WRITE mode.

  • Can you open PDB$SEED read write yourseld? Yes and No.
  • Should you open PDB$SEED read write yourself? Yes and No.
  • How to run upgrade scripts that need to write to PDB$SEED? catcon.pl


In 12.1 you have no reason to open the seed read write yourself. In 12.2 there is one reason when you are in LOCAL UNDO mode, because you may want to customize the UNDO tablespace.

PLSQL promises vs dbms_scheduler chains

10 lines of code vs 80 lines of code! When implementing JS promises in PLSQL, one of the main use cases
is the ability that promises gives, to easily chain together dependent steps defined as functions. Also the
ability to easily pass output from one step along to the next step in the chain.