My RAC Attack session was pretty early, so I headed straight there for the morning.
The OCP lounge always has drinks and food, so regular pitstops there are the norm for me at OOW. If you have OCP or above, it’s really worth dropping by on the first day and getting your ribbons, so you can do regular refreshment stops during the week.
After RAC Attack it is was back to the demo grounds to do another quick tour. Basically, I was looking for new faces to speak to and quizzing people further about stuff I had discussed on previous days. Sometimes you have to let this stuff stew a while before you can think of more questions.
I bumped into Tom Kyte before his SQL Tuning Experts panel session. He said something like, “Ah, Mr Hall”, to which I replied, “Mr? I didn’t do 5 years at evil medical school to be called Mr!” That comment came back to bite me during the panel session when I put my hand up to ask a question and he said something like, “A question from DR Hall…” The shame…
SQL Tuning Experts Panel
Some of the take-home points from this include:
- The optimizer’s short term memory has become longer, as some of the dynamic statistics and cardinality feedback information can now be persisted to the SYSAUX tablespace.
- SQL Monitor is the the best tool in 11g to troubleshoot performance problems.
- SQL Performance Analyzer is a great way to check the impact of changes on SQL performance.
- Stats have to be representative, not necessarily new.
- Pending stats save you from screwing up all your plans every night.
- In 12c, Enhanced Real-Time ADDM runs every 3 seconds to give you up to date advice on things that are happening on your system.
Five Things about SQL and PL/SQL you might not have known.
This included a mix of new stuff in 12c and existing stuff. My laptop battery was dead at this point, so I was making notes on my Nexus 7, so I only recorded the 12c stuff.
- Implicit return of result sets:
- The DBMS_SQL package new contains overloaded RETURN_RESULT procedures to push cursor variables back to the calling client code.
- This is similar to how SQL Server can return result sets using SELECT without defining out parameters.
- SQL*Plus automatically shows the implicit output.
- PL/SQL can manipulate them using the GET_NEXT_RESULT function to return the next cursor variable.
- This is a migration feature, so there is no need to replace existing procedures and functions that return cursor variables to return record sets.
- Global Temporary Table Statistics can be session specific. It is controlled using a statistics preference, allowing them to be set to global or session-specific.
- The cardinality of pipelined table functions was discussed. These is a subtle change in 12c as the cardinality feedback introduced in 11g is persisted in 12c.
Evening Social Events
In the evening it was off to the bloggers meetup. Every year I get to put more real faces to the names and twitter handles I’ve got used to seeing. It’s really good to meet everyone properly and have a little chat.
After that it was off to the appreciation event, or the everlasting buss ride as it turned out to be. I ended up seeing the last couple of songs by Kings of Leon, who sounded OK. I saw most of Perl Jam, but was a little dissapointed. The sound quality was a little poor and they weren’t as tight as I would have expected. That’s not to say they were bad, just not as good as I wanted them to be. I think maybe I should play Ten and pretend I’m twenty again and convince myself it was the best gig ever…
All in all a pretty crazy day…