RAM is the new disk – and how to measure its performance – Part 2 – Tools

In the previous article I explained that the main requirement for high-speed in-memory data scanning is column-oriented storage format for in-memory data. SIMD instruction processing is just icing on the cake. Let’s dig deeper. This is a long post, you’ve been warned.

Test Environment

I will cover full test results in the next article in this series. First, let’s look into the test setup, environment and what tools I used for peeking inside CPU hardware.

I (more...)

We are hiring!

Gluent – where I’m a cofounder & CEO – is hiring awesome developers and (big data) infrastructure specialists in US and UK!

We are still in stealth mode, so won’t be detailing publicly what exactly we are doing ;-)

However, it is evident that the modern data platforms (for example Hadoop) with their scalability, affordability-at-scale and freedom to use many different processing engines on open data formats are turning enterprise IT upside down.

This shift has already been going (more...)

RAM is the new disk – and how to measure its performance – Part 1

RAM is the new disk, at least in the In-Memory computing world.

No, I am not talking about Flash here, but Random Access Memory – RAM as in SDRAM. I’m by far not the first one to say it. Jim Gray wrote this in 2006: “Tape is dead, disk is tape, flash is disk, RAM locality is king” (presentation)

Also, I’m not going to talk about how RAM is faster than disk (everybody knows that), (more...)

The Hybrid World is Coming

Here’s the video of E4 keynote we delivered together with Kerry Osborne a few weeks ago.

It explains what we see is coming, at a high level, from long time Oracle database professionals’ viewpoint and using database terminology (as the E4 audience is all Oracle users like us).

However, this change is not really about Oracle database world, it’s about a much wider shift in enterprise computing: modern Hadoop data lakes and clouds are here to stay. They are already taking over many workloads traditionally executed on (more...)

Old ventures and new adventures

I have some news, two items actually.

First, today (it’s still 18th June in California) is my blog’s 8th anniversary!

I wrote my first blog post, about Advanced Oracle Troubleshooting, exactly 8 years ago, on 18th June 2007 and have written 229 blog posts since. I had started writing and accumulating my TPT script collection a couple of years earlier and now it has over 1000 files in it! And no, I don’t remember (more...)

Advanced Oracle Troubleshooting Guide – Part 12: control file parallel reads causing enq: SQ – contention waits?

Vishal Desai systematically troubleshooted an interesting case where the initial symptoms of the problem showed a spike of enq: SQ – contention waits, but he dug deeper – and found the root cause to be quite different. He followed the blockers of waiting sessions manually to reach the root cause – and also used my @ash/ash_wait_chains.sql and @ash/event_hist.sql scripts to extract the same information more conveniently (note that he had modified the scripts to (more...)

Sqlplus is my second home, part 8: Embedding multiple sqlplus arguments into one variable

I’ve updated some of my ASH scripts to use these 4 arguments in a standard way:

  1. What ASH columns to display (and aggregate by)
  2. Which ASH rows to use for the report (filter)
  3. Time range start
  4. Time range end

So this means whenever I run ashtop (or dashtop) for example, I need to type in all 4 parameters. The example below would show top SQL_IDs only for user SOE sessions from last hour of ASH (more...)

Oracle Exadata Performance: Latest Improvements and Less Known Features

Here are the slides of a presentation I did at the IOUG Virtual Exadata conference in February. I’m explaining the basics of some new Oracle 12c things related to Exadata, plus current latest cellsrv improvements like Columnar Flash Cache and IO skipping for Min/Max retrieval using Storage Indexes:

Note that Christian Antognini and Roger MacNicol have written separate articles about some new features:



Public Appearances 2015

Here’s where I’ll hang out in the following months:

11-12 Feb 2015: IOUG Exadata SIG Virtual Conference (free online event)

  • Presentation: Exadata Performance: Latest Improvements and Less Known Features
  • It’s a free online event, so sign up here

18-19 Feb 2015: RMOUG Training Days (in Denver)

  • I won’t speak there this year, but plan to hang out on Wednesday evening and drink beer
  • More info here

1-5 March 2015: Hotsos Symposium 2015

Oracle In-Memory Column Store Internals – Part 1 – Which SIMD extensions are getting used?

This is the first entry in a series of random articles about some useful internals-to-know of the awesome Oracle Database In-Memory column store. I intend to write about Oracle’s IM stuff that’s not already covered somewhere else and also about some general CPU topics (that are well covered elsewhere, but not always so well known in the Oracle DBA/developer world).

Before going into further details, you might want to review the Part 0 of this series and also our (more...)