Data Pump import makes me crabby

I’m sitting here watching the import of a moderately sized database via transportable tablespaces.  You know…the thing you use when a full export / import would be too slow, and this is meant to be … well…fast.

And fast it is.. until it reaches the following step:

Processing object type TRANSPORTABLE_EXPORT/TABLE_STATISTICS

Now understandably, there’s plenty of stats to import, so its fair that it should take a little while.  But a quick look (more...)

Adaptive plans and v$sql_plan and related views

Adaptive plans are one of the coolest new optimiser features in Oracle 12c. If you haven’t seen or heard about them in detail I recommend the following resources:

There is a caveat with this though: if your tuning script relies on (more...)

How to avoid a salted banana! (SQL tuning)‏

Dear NoCOUG members and friends,

You’re going to enjoy the new issue of the NoCOUG Journal. Click here to download it.

  • Lothar Flatz talks about the biggest issue in SQL tuning: the “salted banana.” We predict that the phrase “salted banana” will become as widely known in the Oracle community as “compulsive tuning disorder.” Click here to go directly to Lothar’s article.
  • Janis Griffin—a.k.a. the Looney Tuner—explains why the Oracle (more...)

Do The LGWRs (10,11,12c) Always Sleep For The Full Three Seconds?

Do The LGWRs (10,11,12c) Always Sleep For The Full Three Seconds?


Back in June I wrote (included a video) about the Oracle Database log writer(s) "3 second sleep rule." That's the rule we were all taught by our instructors when we started learning about Oracle yet never really knew if it was true. In that post, I demonstrated Oracle Database log writer background processes are normally put to sleep for three seconds.

In this (more...)

Setup Streams Performance Advisor (UTL_SPADV) for #GoldenGate

With Oracle “merging” Oracle GoldenGate into Oracle Streams (or vise-versa), capturing statitics on the intergrated extract (capture) or integrated replicat (happy) will be needed.  In order to do this, the Streams Performance Advisor (UTL_SPADV) can be used.  Before using the Stream Performance Advisor, it needs to be configured under the Streams Administrator, i.e. Oracle GoldenGate user.  In my test lab, I use a user named GGATE for all my Oracle GoldenGate work.

Configure user (more...)

FBI Bug reprise

I’ve just had cause to resurrect a blog note I wrote three years ago. The note says that an anomaly I discovered in 9.2.0.8 wasfixed in 10.2.0.3 – and this is true for the simple example in the posting; but a recent question on the OTN database forum has shown that the bug still appears in more complex cases.  Here’s some code to create a table and two indexes:


create table t1
 (more...)

2014 in review

Happy New Year!

So many things happened in the past six months, I really can’t tell how quickly the time passed. As people say the life is what happens to you while you are making plans for the future.

I wish I had the time to blog more in the past year and I plan to change this in the New Year!

2014 was really successful for me. I worked on some really interesting projects, (more...)

CRS Timezone

Interesting problem – database was running normally without any issues and added to OCR.  But the log file started reporting a different time for all activities – for example.

Database and server is showing a time 4:25 while alertlog is ahead of 5 hours @9:25!

<pre>
oracle@prod # tail alert_xxxxxxx.log

Recovery of Online Redo Log: Thread 2 Group 16 Seq 129057 Reading mem 0

  Mem# 0: +ORAINDEX1/prod/onlinelog/group_16.282.864560747

Mon Jan 12  (more...)

Installing Oracle 12.1.0.2 RAC on Oracle Linux 7-part 2

In the first part of the article series you could read how a kickstart file made the installation of Oracle Linux 7 a lot more bearable. In this part of the series it’s all about configuring the operating system. The installation of Grid Infrastructure and the Oracle database is for another set of posts.

There are quite some differences between Oracle Linux 6 and 7

To me the transition from Oracle Linux 6 to 7 (more...)

Oracle ZFS Network Attached Storage ZS4-4 System for Oracle Database 12c

Oracle has recently announced its latest generation of Network-attached Storage or NAS system namely the Oracle ZFS Storage ZS4-4. With the new Oracle Database 12c in place, ZS4-4 is capable of providing some brand new exciting features, which in the words of Oracle VP, Mr. John Fowler expand Oracle’s leadership in NAS performance. New Capabilities […]

The post Oracle ZFS Network Attached Storage ZS4-4 System for Oracle Database 12c appeared first on VitalSoftTech.

Video Tutorial: XPLAN_ASH Active Session History – Introduction

I finally got around preparing another part of the XPLAN_ASH video tutorial.

This part is about the main funcationality of XPLAN_ASH: SQL statement execution analysis using Active Session History and Real-Time SQL Monitoring.

In this video tutorial I'll explain what the output of XPLAN_ASH is supposed to mean when using the Active Session History functionality of the script. Before diving into the details of the script output using sample reports I provide some overview and (more...)

Monsters Ate My Repository Database

I applied the December Bundle Patch for OEM 12.1.0.4 earlier this week and kicked off a series of agent upgrades.  Then monsters at my repository database.

Bug 19458672 caused the newly upgraded agents to hang and to consume all the CPU cycles on the repository database host.  It happened during the final step of registering each agent with their new release number when executing:

BEGIN
em_policy.handle_type_meta_ver_change ( :1);
END;

The one-off patch  (more...)

Toad world’s Oracle Pro for January 2015 – truly honored

Thank you Toad for honoring me with 'Toad World's Oracle Pro for January 2015'. I am indeed truly touched for the honor.


http://www.toadworld.com/platforms/oracle/default.aspx?Redirected=true

I thank my family, all friends, colleagues, Oracle community, my readers, Chris and Steve Hilker from Toad for your support and encouragement.

Cloud Control : 12.1.0.7 Plugin Patch

I applied some of the 12.1.0.7 plugin patches to our Cloud Control installation today. We already have Cloud Control 12.1.0.4 installed, so this was just a case of updating the plugins.

Here’s a quick overview of what I did.

  • Backup up everything! Database and file system.
  • Setup > Extensibility > Self Update
  • Download the latest versions of the plugins. The minimum you can really get away with is “Oracle Database (more...)

Understanding Flash: Floating Gates and Wear

OLYMPUS DIGITAL CAMERA

One of the important characteristics of flash memory is wear. We know from previous articles in this series that flash packages consist of dies, which contain planes, which contain blocks, which in turn contain pages. We also know that these pages contain individual cells which store the bits of data… but to understand what wear is we need to look a little bit closer at those cells, where we will find something called (more...)

count(*) – again !

Because you can never have enough of a good thing.

Here’s a thought – The optimizer doesn’t treat all constants equally.  No explanations, just read the code – execution plans at the end:


SQL> drop table t1 purge;
SQL> create table t1 nologging as select * from all_objects;
SQL> create bitmap index t1_b1 on t1(owner);

SQL> alter session set statistics_level = all;

SQL> set serveroutput off
SQL> select count(*) from t1;
SQL> select * from table(dbms_xplan. (more...)

enq: SQ – contention

Yesterday, I have seen huge waits “enq SQ – contention’”  – in every snapshot there were thousands of waits.  But the fix was so simple!  Here is the root cause of the issue –

When you select from a sequence, the NEXTVAL generated from a the seq$ table if it is not cached.  If it is cached, it will be available in a memory structure and no need to generate the value (more...)

Je suis Charlie

Je suis Charlie Bien sûr, moi aussi, je suis Charlie, moi.

Histograms Tidbits

Make sure histograms exist on columns with uneven data distributions to ensure that the optimizer makes the best choice between indexes and table scans.




For range scans on data that is not uniformly distributed, the optimizers’ decisions will be improved by the presence of a histogram.

Histograms increase the accuracy of the optimizer’s cost calculations but increase the overhead of statistics collections. It’s usually worth creating histograms for columns where you believe the data will (more...)

Oracle GoldenGate Processes – Part 4 – Replicat

The replicat process is the apply process within the Oracle GoldenGate environment.  The replicat is responsible for reading the remote trail files and applying the data found in cronilogical order.  This ensures that the data is applied in the same order it was captured.  

Until recently there was only one version of a replicat, that version was the classic version.  As of 12.1.2.0, there are now three distinct versions of a (more...)