ilOUG meetup: Oracle 12c New Features For Better Performance (slides)

It’s been a while since the Israeli user group (iloug) had a technology meetup (SIG meeting). The last time that happened was over two years ago – and since then, we only had the bigger conferences with guests from all over the world. Yesterday we renewed that long time tradition and held such a meetup.

Although I am not part of the OUG board (and not for the lack of trying, just no elections for (more...)

Oracle Database Cloud (DBaaS) Performance – Part 4 – Network

In the last part of this installment I'll have a brief look at the network performance measured in the Oracle DBaaS environment, in particular the network interface that gets used as private interconnect in case of RAC configuration. The network performance could also be relevant when evaluating how to transfer data to the cloud database.

I've used the freely available "iperf" tool to measure the network bandwidth and got the following results:

[root@test12102rac2 ~]# iperf3 (more...)

Long-running INSERT

On one of the databases I’m looking after (11.2.0.4, Solaris, non-RAC), several different INSERT statements (all into tablespaces with manually managed segments) suffer from occasional hiccups. The symptoms are always the same: in one of the sessions, the INSERT gets stuck doing lots of single-block I/O against one of the indexes on the inserted table, and if other sessions are running similar INSERTs, they hang on enq: TX – index contention. The (more...)

Oracle Database Cloud (DBaaS) Performance – Part 3 – Storage – 12.2 Update

Recently I repeated the I/O related tests on a 12.2.0.1 instance for curiosity and was surprised by the fact that I consistently got significantly better results as on 11.2.0.4 and 12.1.0.2.

Now you're probably aware that the version 12.2 so far is "cloud-only", so I can't tell / test whether the version 12.2 is generically providing that increased performance or whether Oracle has optimized (more...)

Script: Inactive Parallel QC Holding Parallel Processes

Working on a data warehouse system can be quite challenging, as I mentioned in the post from yesterday. One of the things we need to take care of is the amount of parallel processes that are in used at all times. Yesterday I wrote about how to locate downgraded sessions. Today we will look at another aspect – who “steals” parallel processes and what can we do to solve it.

One of the biggest thieves (more...)

Oracle Database Cloud (DBaaS) Performance – Part 2 – Storage

In this second part of this installment I'll focus on the performance figures related to I/O encountered when the corresponding tests were performed on the platform.

IOPS

When running with minimum sized buffer cache, direct and asynchronous I/O enabled, the following average read-only IOPS figures were measured over a period of several days (this is the test described in part three of the "performance consistency" series) .

First, running on a 4 OCPU single instance configuration (more...)

web scale patterns in the bol.com back office – Event Sourcing

web scale patterns in the bol.com back office – Event Sourcing

Last week we started a series of blog posts we show you how we use “web scale” patterns to achieve scaleability and flexibility in our back office software. Last weeks pattern we discussed was CQRS. This week we will dive in to Event Sourcing. Showing you how this doesn’t just solve a technical problem, they helps us solve our business problems!

Event Sourcing

(more...)

Oracle Database Cloud (DBaaS) Performance – Part 1 – CPU

After having looked at the performance consistency provided by the Oracle Database Cloud offering in the previous series, I'll focus here on the raw performance figures I've measured during my tests, starting with the CPU related performance findings.

One of the first surprises is related to the fact that Oracle uses a unit called "OCPU" to specify the CPU capacity provided, which is explained here:

So one "OCPU" is supposed to represent one core (more...)

eProseed Oracle Open World 2016 debrief – Oracle Database & Oracle Management Cloud

For people interested, here the slide desks used internally to debrief my colleagues regarding Oracle…

Do you suffer from Storage Stockholm Syndrome?

The last year at DSSD (now a part of Dell EMC) has been an extremely interesting one for me, and I’ve learned a great deal, which is always good. Some of the lessons have been surprising, though… One of them is what I will rather dramatically refer to as Storage Stockholm Syndrome. Stockholm Syndrome is … Continue reading "Do you suffer from Storage Stockholm Syndrome?"

#DOAG2016 wrap up

doag_wegweiser

Another DOAG is over and here are my summary.

Day 1

Unfortunately the early train from duesseldorf arrives not before 9:30, so I missed the first morning slot. But on the other hand I this was the slot where I had to decide between 8 presentations, which I’m interested in.

The first soft skill presentation was about creative techniques beyond brain storming. The mentioned 3 techniques was all unknown for me, maybe I give it (more...)

Oracle Database Cloud (DBaaS) Performance Consistency – Part 7

This part of the series is supposed to cover the results of I/O related tests performed on the Amazon RDS Oracle cloud instance.
As mentioned in the previous part of this series I've only used the "General Purpose SSD" storage type since the "Provisioned IOPS" storage was simply to expensive to me and it wasn't possible to get a trial license for that storage type.

Now one key aspect of the "General Purpose SSD" storage (more...)

HotSpot JVM garbage collection options cheat sheet (v4)

After three years, I have decided to update my GC cheat sheet.

New version finally includes G1 options, thankfully there are not very many of them. There are also few useful options introduced to CMS including parallel inital mark and initiating concurrent cycles by timer.

Finally, I made separate cheat sheet versions for Java 7 and Java 8.

Below are links to PDF versions

Oracle Database Cloud (DBaaS) Performance Consistency – Part 6

In the next parts of this series I'll have a look at the results of similar performance consistency tests performed on a comparable Amazon RDS Oracle cloud database instance.

Let's start with the configuration used, which was an Amazon RDS "db.m4.2xlarge" instance - the latest RDS generation available at time of testing. This is an 8 VCPUs resp. Hyper Threads / 4 cores configuration with 32GB of RAM.
As storage I've used (more...)

Oracle Database Cloud (DBaaS) Performance Consistency – Part 5

This is the fifth part of this installment, and before coming to comparisons to other cloud providers, in this part I show the results of the read-only test that I've already described in part three of this series, but repeated at a later point in time. The test setup was identical and can be checked in the mentioned previous part.

The reason for running the test again was the fact that I was informed during (more...)

Visualizing System Statistics in SQL Developer – OTN Appreciation Day

Tim Hall inspired me with his #ThanksOTN (or “OTN Appreciation Day“) campaign to continue my mini-series on leveraging SQL Developer Reports for DBA tasks. Today with visualizing historical System Statistics from Statspack for performance analyses. #ThanksOTN I have three favourite Oracle features to rave about today: Analytic SQL Statspack SQL Developer (particularly the reports)! System Statistics As the […]

Oracle Database Cloud (DBaaS) Performance Consistency – Part 4

This is the fourth part of this installment, comparing the performance consistency of the DBaaS cloud offering with a dedicated physical host. This time the previous read-only test was modified to be a 100% update read-write test. So every row read was updated in the following way:

begin
  loop
    for rec in (
          select /*+
              index(t_o)
          (more...)

Spark 2.0 Performance Improvements Investigated With Flame Graphs

Topic: This post is about performance optimizations introduced in Apache Spark 2.0, in particular whole-stage code generation. A test case is introduced and investigated with diagnostic tools.


Introduction: performance troubleshooting of a slow query using parallel query execution in a Hadoop cluster

The idea for this post comes from a performance troubleshooting case that has come up recently on our database services. It started with a user reporting slow response time from a query (more...)

Unified Auditing – some insights

Oracle 12c Unified Auditing is a brand new feature in the latest Oracle version which consolidates database level auditing records into a single location. DBAs can access the audit information from the view UNIFIED_AUDIT_TRAIL for all kind audit records, and they are

SQL> select distinct COMPONENT from all_unified_audit_actions;

COMPONENT
----------------------------------------------------------------
Direct path API
RMAN_AUDIT
Database Vault
XS
Label Security
Datapump
Standard
FineGrainedAudit

8 rows selected.

UNIFIED_AUDIT_TRAIL is a view owned by SYS and a public (more...)

Hotsos 2016 Recap

I wanted to go to Hotsos Symposium for quite some time, having heard so many great topics from there for years. And every time I was a bit lazy to think about what I can talk about. Apparently I thought that everything I know is well covered elsewhere, so why would I be accepted. Plus all these complexities of budget, getting a visa, travel arrangements, jet lag, and personal matters in between. Last year, when (more...)