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#OakTable World at Oracle OpenWorld 2014

WhereChildren’s Creativity Museum, 221 4th St, San Francisco

When:  Mon-Tue, 29-30 September, 08:30 – 17:00 PDT

Back to technology: Is it effective to place Oracle REDO on SSD?

Ever since I was asked to improve the throughput of an actual general ledger posting job involving Oracle in December 1993 on some hardware where solid state disk (SSD) was available (at high cost relative to “spinning rust” or hard disk drives [HDD]), I have been trying to explain the overall advantage of placing different types of the different Oracle storage selectively on SSD.

When FLASH SSD arrived on the scene, studies quickly arose that writing to FLASH SSD is often not as fast as writing to disk drives dedicated to receiving those writes.

Today I’ll try to explain why I don’t care.

While there was some advantage to writing to SSD in my tests (which were to RAM based SSD on a VAX), the write speed to online REDO was not a significant part of the advantage of placing online REDO on SSD.

Shrink Tablespace

A recent question on the OTN database forum raised the topic of returning free space in a tablespace to the operating system by rebuilding objects to fill the gaps near the start of files and leave the empty space at the ends of files so that the files could be resized downwards.

This isn’t a process that you’re likely to need frequently, but I have written a couple of notes about it, including a sample query to produce a map of the free and used space in a tablespace. While reading the thread, though, it crossed my mind that recent versions of Oracle introduced a feature that can reduce the amount of work needed to get the job done, so I thought I’d demonstrate the point here.

Private Cloud and Lifecycle Management with EM12c at OOW14

Yet again the monster that is Oracle Open World is about to take over San Francisco. I won’t be making it this year, but considering we had something like 60,000 attendees last year I’d hate to see what the numbers are gonna be this year! :)

To try and make it a little easier for you to find all the Private Cloud and Lifecycle Management with EM12c material, here are the ones I know about. If you know of any I’ve missed, feel free to add them in the comments field below! Note that this is only the Private Cloud and Lifecycle Management material – the complete master list of all EM material can be found in the master Focus On EM12c document.

#CloneAttack at Oracle OpenWorld 2014

Delphix and Dbvisit will be at the OTN Lounge in the lobby of Moscone South from 3:30 – 5:00pm on Monday 29-Sept.  Come join us to hear about #CloneAttack and #RepAttack, two great hands-on learning opportunities.

What:

Oracle Midlands Event #6 : Registration Open

Registration for Oracle Midlands Event #6 is now open. Here’s the information from the website.

OracleMidlands6

I’ve registered. See you there!

Cheers

Tim…

Oracle Midlands Event #5 : Summary

Oracle Midlands Event #5 happened last night.

First up was Martin Widlake speaking about clustering data to improve performance. The cool and scary thing about Oracle is you often go into session like this thinking it’s all going to be stuff you already know, then you realise how much you either didn’t know in the first place, or had forgotten. A couple of times Martin asked questions of the audience and I felt myself shrinking back in my seat and chanting the mantra, “Don’t pick me!”, in my head. :)

About index range scans, disk re-reads and how your new car can go 600 miles per hour!

Despite the title, this is actually a technical post about Oracle, disk I/O and Exadata & Oracle In-Memory Database Option performance. Read on :)

If a car dealer tells you that this fancy new car on display goes 10 times (or 100 or 1000) faster than any of your previous ones, then either the salesman is lying or this new car is doing something radically different from all the old ones. You don’t just get orders of magnitude performance improvements by making small changes.

Perhaps the car bends space around it instead of moving – or perhaps it has a jet engine built on it (like the one below :-) :

12c In-Memory on RAC

I started looking into In-Memory on RAC this week. Data can be distributed across RAC nodes in a couple of different ways. The default is to spread it across the available nodes in the cluster. So if you had a 2 node cluster, roughly 50% of the data in your table or partition would be loaded into the column store in each of the 2 instances.

Migrating to ASM

On the Maximum Availability Architecture website, there’s a paper on Best Practices for Database Consolidation. It’s a great paper, as you’d expect from the MAA guys (well, apart from that awful term alert I had to add! :) ). Since database consolidation is an area I work in a lot, I thought I’d start looking at implementing as much of their recommendations as I could in Enterprise Manager, which of course is my tool of choice.