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Exadata Smart Scan predicate offloading and sequence.NEXTVAL

There was a question in the twitter-sphere about whether using sequences (sequence.NEXTVAL) in your select query’s projection list would somehow disable smart scans happening?

Another Oracle internals hacking session about how Oracle parameters work – tomorrow! :-)

Ok fellow internals geeks, tomorrow’s going to be another 1-hour hacking session (which will probably take 2 hours) with me. It’s about how Oracle parameters work and all the different types of them too. See the registration link for more info:

Date: 12 april 2012

Create a database link with the new host:port/service syntax

I just noticed that (finally) in 11.2 this syntax is supported:

  2  CONNECT TO tanel IDENTIFIED BY password 
  3  USING 'exadb03:1521/DEMO';
Database link created.

This just makes life a bit easier as there’s no need to use the long TNS format entry (or a tnsnames.ora/LDAP alias). It might work in 11.1 too (haven’t tested) but it didn’t work on …

In case you didn’t know, the sqlplus supports such an easy connect method since 10g:

Oracle Core: Essential Internals for DBAs and Developers book by Jonathan Lewis

In case you didn’t know, Jonathan Lewis’es new Oracle Core: Essential Internals for DBAs and Developers book is out (for a few weeks already).

I was the technical reviewer for that book and I can say it’s awesome! It will likely be the best Oracle internals book out there for the coming 10 years, just like Steve Adams’es Oracle Internal Services book was in the last decade :) 

My UKOUG 2011 appearances

I’m just sitting in the airport, waiting for my Birmingham flight and it’s probably time to mention when and where I’m hanging out too:


Good blogs to read

If you’re looking for more good Oracle blogs to read, here are two very good ones:

Profiling trace files with preprocessor external tables in 11g and some parallel execution hacking

If you work with SQL Trace files (and profile them) then you should check out the awesome novel use of the “external table preprocessor” feature explained by Adrian Billington here:

Evil things are happening in Oracle

Relax, I’m talking about the Oracle Database kernel here, not the corporation ;-)

Here’s a couple of more reasons why not to play around with undocumented debug events unless you’re really sure why and how would they help to solve your specific problem (and you’ve gotten a blessing in some form from Oracle support too):

What the heck is the SQL Execution ID – SQL_EXEC_ID?

Ok, I think it’s time to write another blog entry. I’ve been traveling and dealing with jetlag from 10-hour time difference, then traveling some more, spoken at conferences, drank beer, had fun, then traveled some more, trained customers, hacked some Exadatas and now I’m back home.

Anyway, do you know what is the SQL_EXEC_ID in V$SESSION and ASH views?

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