The village idiot

If you are not familiar with the term Village Idiot, then Wikipedia provides a sufficient definition from which I can base this blog post.

https://en.wikipedia.org/wiki/Village_idiot

“The village idiot … is a person known for ignorance or stupidity”

Over the past couple of weeks I’ve been flying a bit.  First was OpenWorld and OracleCode in New Delhi in India, and from there, I was heading straight from there to Cleveland, Ohio for the (more...)

Finished reading the Snowflake database documentation

I just finished reading the Snowflake database documentation and I thought I would blog about my impressions. I have not spent a lot of time using Snowflake so I can not draw from experience with the product. But, I read all the online documentation so I think I can summarize some of the major themes that I noticed. Also, I have read a lot of Oracle database documentation in the past so I can compare (more...)

SQL FUNDAS

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The post SQL FUNDAS appeared first on DBACLASS.

Did You Know #19 – Using LIKE

The LIKE operator is a very useful one. It is used to match strings with partial match while using the underscore (‘_’) as a single character wildcard and the percentage sign (‘%’) as multiple character wildcard. There are a few things you should know and some tricks you can use with the LIKE operator: The underscore … Continue reading Did You Know #19 – Using LIKE

Cedar’s Oracle Talent Acquisition Cloud Event / Team

Earlier this week Cedar held its Oracle Talent Acquisition Cloud event in Oracle’s London City office. We have a really strong team of UK-based Talent Acquisition specialists within our ranks:

Taleo Team 2 (plain background)

Jo, Prachi, Marc and Mel are all experts in the various aspects of Oracle Talent Aquisition Cloud – Taleo Recruit, Sourcing and Onboarding – and Cedar has multiple implementations under our belt covering all of the above products, so we were able to put on (more...)

Comparing Expression Lists (not tuples)

This post is a long-winded answer to a question Bryn Llewellyn asked me on Twitter about comparing expression lists.

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 (more...)

Oracle Database 12.2.0.1 – Application PDB unable to sync – An update

RSS content

In my last post, I had demonstrated that without OMF, If an  application creates new datafiles, application PDB’s always fails to sync with the  application.  When I mentioned it to Tim, he raised an SR with Oracle who have clarified that it is  Bug 21933632. Although  it is not documented yet but OMF is mandatory if using the Application Container feature. If it is attempted to sync application PDB’s  with an  application that creates   non-OMF (more...)

Quick tip–identity columns

Lets say I’ve been reading about schema separation, and thus I am going to have a schema which owns all of my objects, which I’ll call APP_OWNER, which will have no connection privilege and a separate schema called APP_ADMIN which will take care of all of the DDL tasks.

Here’s my setup:


SQL> create user app_owner identified by app_owner;
 
User created.
 
SQL> grant
  2    create session,
  3    create any table,
  4    create any sequence,
  5   (more...)

RTFM

Imagine you’re fairly new to Oracle and don’t have a lot of background information at your fingertips; then one day someone tells you to read the manual pages for the view dba_free_space. Look carefully at this sentence:

Note that if a data file (or entire tablespace) is offline in a locally managed tablespace, you will not see any extent information.

Can you spot the error ? Did you spot the error when you first read the (more...)

DOAG Exaday 2017: a preview

I am quite excited to have been accepted to speak at the upcoming DOAG Exaday taking place June 20 in Frankfurt. It is the third time I have been lucky enough to present at the event, having spoken both in Frankfurt in Hamburg in previous years.

As you can probably imagine by looking at this weblog, I am a great supporter of the Oracle Engineered Systems community. My interest is not limited to Germany: I still remember (more...)

Session killin’ time

As developers, sometimes we set something running that we wish we hadn’t Smile  And naturally, we’d like to be good IT citizens and clean up the mess as quick as we can.  (For most of us, this means – cover our tracks before the phone rings about smoke coming out of the server).  But of course, getting an administrator to hand over the trigger to let you have the ALTER SYSTEM KILL SESSION (more...)

Submitted two abstracts for Oracle OpenWorld 2017

I submitted two abstracts for Oracle OpenWorld 2017. I have two talks that I have thought of putting together:

  • Python for the Oracle DBA
  • Toastmasters for the Oracle DBA

I want to do these talks because they describe two things that I have spent time on and that have been valuable to me.

I have given several recent talks about Delphix. Kyle Hailey let me use his slot at Oaktable World in 2015 which was at the same time (more...)

Transportable Tablespace–part 2

I did a little demo of sharing a tablespace between two databases a few days back – you can see the details here or by just scrolling down Smile if you’re on the home page.

To avoid clouding the demonstration I omitted something in the details, but I’ll share that now, because it could be critical depending on how you currently use transportable tablespaces.

Let me do the most basic of examples now, transporting a tablespace (more...)

How to find the object that caused ORA-08103 error

A developer told me that two package executions died with ORA-08103 errors and he didn’t know which object caused the errors.

I found two trace files that had the following contents:

*** SESSION ID:(865.1201) 2017-04-17 10:17:09.476
OBJD MISMATCH typ=6, seg.obj=21058339, diskobj=21058934, dsflg=100000, dsobj=21058339, tid=21058339, cls=1

*** SESSION ID:(595.1611) 2017-04-17 10:17:35.395
OBJD MISMATCH typ=6, seg.obj=21058340, diskobj=21058935, dsflg=100000, dsobj=21058340, tid=21058340, cls=1

Bug 13844883 on Oracle’s support site gave me the idea to (more...)

Sharing a tablespace between 2 databases

I was reading an interesting discussion today about multiple databases each containing large amounts of read-only data.  If that read-only data is common, then it would make sense to have a single copy of that data and have both databases share it.

Well, as long as you can isolate that data into its own tablespace, then you can do that easily with Oracle by transporting the metadata between two databases and leaving the files (more...)

Optimizer bug fix makes a query run more than 3 times slower

I’m working on an 11.1.0.7 to 11.2.0.4 upgrade and found a handful of queries that run more than 3 times longer on 11.2.0.4 than 11.1.0.7. The data and optimizer statistics are very similar on the two test databases. I’m pretty sure that an optimizer bug fix caused this difference. So, the irony is that a fix to the optimizer that we get with (more...)

ASM Disks Scripts

One of my customers is working with ASM and their database grows really fast. So every one in a while we need to add another ASM disk to the system. Before I add a new ASM disk, I usually verify that there is indeed a new disk in the system that is not being used. … Continue reading ASM Disks Scripts

SUM is better than DISTINCT

There is a good chance that (based on this blog post title) that you’re expecting a post on SQL, and that’s understandable. But I’ll come clean nice and early – that was just to lure you in Smile 

The post is about SUM and DISTINCT, but not in the technical sense.

A few days ago, fellow OakTable member Jonathan Lewis put a post on his blog: https://jonathanlewis.wordpress.com/2017/04/10/ask-jonathan/ where he is launching a mechanism (more...)

Question: Table names singular or plural?

Yesterday I put a question on twitter, to find out what others prefer: table names using singular or plural form. I expected one or two replies, not an avalanche :-)

As expected there were all kind of replies going either singular or plural. Some (more...)