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Database Management and Performance – OraNA :: Oracle News Aggregator

Read and monitor Oracle related blogs and news sources, all in one place.

Last Build Date: Fri, 19 Jan 2018 15:19:54 +0000


Nested MVs

Fri, 19 Jan 2018 14:43:24 +0000

A recent client was seeing a very large redo penalty from refreshing materialized views. Unfortunately they had to be refreshed very frequently, and were being handled with a complete refresh in atomic mode – which means delete every row from every MV then re-insert every row.  The total redo was running at about 5GB per […]

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Should I use SQL or Python?

Thu, 18 Jan 2018 19:57:34 +0000

We had an outage on an important application last Thursday. A particular SQL statement locked up our database with library cache: mutex X waits. I worked with Oracle support to find a bug that caused the issue and we came up with a good workaround. The bug caused a bunch of shared cursor entries. So, I […]

Docker and Oracle Databases : Finding the Sweet Spot

Thu, 18 Jan 2018 18:54:47 +0000

One of the questions I’m asked, and indeed have asked myself on numerous occasions, is how do databases fit into the Docker world? More specifically, how does the Oracle database fit into the Docker world? There is some Boring Context at the end of post. Happy for you to ignore it, but please read it […]

Message-Oriented Oracle RAC wait events

Thu, 18 Jan 2018 17:51:47 +0000

Message-Oriented Oracle RAC wait event The message-oriented wait event statistics indicate that no block was received because it was not cached in any instance. Instead, a global grant was given, enabling the requesting instance to read the block from disk or modify it. If the local instance is the resource master, the grant happens immediately.If […]

RMOUG Training Days 2018

Thu, 18 Jan 2018 17:35:00 +0000

Next month RMOUG (Rocky Mountain Oracle User Group) will have their annual Training Days conference in Denver. In the past, being in Israel, I wasn’t exposed to most of these “local” OUG conference in North America (I mainly went to European ones) and even if I was, it was difficult for me to attend (money-wise […]

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Upgrading GoldenGate Microservices Architecture – GUI Based

Thu, 18 Jan 2018 16:45:00 +0000

In August of 2017, Oracle released two architectures for Oracle GoldenGate. These architectures were the Classic Architecture and the Microservices Architecture. Since then there has been some discussion around upgrading Oracle GoldenGate to Microservices. Due to the change in architecture, there is no direct upgrade path from Classic Architecture to Microservices Architecture. If you want […]

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CDB Views and Query Optimizer Cardinality Estimations

Thu, 18 Jan 2018 16:39:59 +0000

Today I faced a performance problem caused by a bad cardinality estimation involving a CDB view in a multitenant environment. While solving the problem I did a number of observations that I try to summarize in this blog post. First of all, when checking the execution plan of a query already running for more […]

Column Stats

Thu, 18 Jan 2018 14:22:52 +0000

I’ve made several comments in the past about the need for being selective when gathering objects statistics with particular reference to the trade-offs when creating histograms. With Oracle 12c it’s now reasonably safe (as far as I’m concerned) to set a method_opt as a table preference that identifies columns where you expect to see Frequency […]

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opatch version – Initial heap size set to a larger value than the maximum heap size

Thu, 18 Jan 2018 10:47:11 +0000

The below issue was faced by my fellow DBA while in checking OPatch version in Grid Home, Interestingly the same OPatch  utility works fine in RDBMS Home Issue-OPatch version command failed with below error on GRID_HOME but it was working fine on DB home Error:-  opatch version Error occurred during initialization of VM Initial heap […]

Oracle 12c SE2 installation guide on OEL 7.4

Thu, 18 Jan 2018 10:12:43 +0000

Please find the document here Oracle 12c SE2 installation guide on OEL 7

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ORA-39095: Dump File Space Has Been Exhausted: Unable To Allocate

Thu, 18 Jan 2018 05:48:20 +0000

PROBLEM: While running expdp with filesize parameter, got below error.   expdp dumpfile=full1.dmp logfile=full1.log directory=T filesize=100m full=y Starting “SYS”.”SYS_EXPORT_FULL_01″: /******** AS SYSDBA dumpfile=full1.dmp logfile=full1.log directory=T filesize=1m full=y Estimate in progress using BLOCKS method… Processing object type DATABASE_EXPORT/EARLY_OPTIONS/VIEWS_AS_TABLES/TABLE_DATA Processing object type DATABASE_EXPORT/NORMAL_OPTIONS/TABLE_DATA Processing object type DATABASE_EXPORT/NORMAL_OPTIONS/VIEWS_AS_TABLES/TABLE_DATA Processing object type DATABASE_EXPORT/SCHEMA/TABLE/TABLE_DATA Total estimation using BLOCKS method: 251.0 […]

Migrating Function based indexes from Oracle to PostgreSQL

Thu, 18 Jan 2018 05:04:31 +0000

In this post, I will share  challenges with function based index in PostgreSQL . I was performing database migration from Oracle to PostgreSQL and used AWS Schema Conversion Tool(SCT) for converting the database schema.AWS Schema conversion tool takes care of automatically converting schema from one database engine to other. You can get more information about…

GDPR ‘Murica!

Wed, 17 Jan 2018 22:08:33 +0000

Just over a year ago, an alarm of emails, posts and projects arose in Europe surrounding the General Data Protection Regulation, also known with the acronym, GDPR.  It was as if someone had poked the sleeping bear of IT and woke it and boy, was it grumpy. Suddenly EU technologists were learning all about advanced […]

How to run on Exadata

Wed, 17 Jan 2018 15:16:23 +0000

Very often when creating a Support Request (SR) for an issue on an Oracle Exadata Database Machine, you’ll need to run the script ““.  Which is the “Oracle Exadata Database Machine – Diagnostics Collection Tool“. More information can be found on My Oracle Support (MOS) Note: SRDC – EEST Sundiag (Doc ID 1683842.1) To run […]

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VirtualBox 5.2.6

Wed, 17 Jan 2018 14:39:21 +0000

VirtualBox 5.2.6 has been released. I predicted Christmas day, but they came in a little early… The downloads and changelog are in the usual places. I’ve done the installation on my Windows 7 PC at work and it seems fine. Unlike the last two versions (5.2.2 and 5.2.4), the automatic download of the extension pack […]

Start and stop firewall OEL 7

Wed, 17 Jan 2018 12:33:34 +0000

Check the status [root@ezylebuat ~]# systemctl status firewalld ● firewalld.service – firewalld – dynamic firewall daemon Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled) Active: active (running) since Wed 2018-01-17 06:37:59 EST; 24min ago Stop the firewall [root@ezylebuat ~]# systemctl stop firewalld ● firewalld.service – firewalld – dynamic firewall daemon Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: […]

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The security token could not be authenticated or authorized

Wed, 17 Jan 2018 06:05:40 +0000

Client received SOAP Fault from server: The security token could not be authenticated or authorized Please see the server log to find more detail regarding the exact cause of the failure.Error while calling Oracle web service. Solution: SOAP Wsdl granted user password might be changed. Please check  

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Grouping Oracle Rac Wait Events

Tue, 16 Jan 2018 22:52:21 +0000

To determine the amount of work and cost related to inter-instance messaging and contention, examine block transfer rates, remote requests made by each transaction, the number and time waited for global cache events as described under The response time for cache fusion transfers is determined by the messaging and processing times imposed by the physical […]

Block-Related Oracle Rac Wait Events – Part 2

Tue, 16 Jan 2018 21:44:10 +0000

An event can be anything that Oracle has to perform on behalf of a set of instructions sent by the user interface. The term “wait” is used because every time a user connects to your application, a resource is allocated to perform tasks on its behalf. The waiting comes when a session is waiting for […]

Installing PSU (GI+RAC+JVM)

Tue, 16 Jan 2018 17:30:49 +0000

I’ve installed quite a few PSUs in my professional life, but this time, it was something else. I’m talking about a RAC environment with 2 nodes and a database containing JVM, so this was a complex patch to begin with. The problem is the the readme is incomplete and on top of that I ran […]

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HAProxy High Availability Setup

Tue, 16 Jan 2018 09:43:08 +0000

In the modern world where everyone wants to be always connected, High Availability became one of the most important feature for a system. For example if you are running  a system you don't want a failure in one piece of your architecture impacts the  whole system. You have to make all the components of your […]

Using Spark to join data from CSV and MySQL Table

Mon, 15 Jan 2018 13:31:15 +0000

Yesterday, I explained how we can access MySQL database from Zeppelin which comes with Oracle Big Data Cloud Service Compute Edition (BDCSCE). Although we can use Zeppelin to access MySQL, we still need something more powerful to combine data from two different sources (for example data from CSV file and RDBMS tables). Spark is a […]

Histogram Hassle

Mon, 15 Jan 2018 13:01:00 +0000

I came across a simple performance problem recently that ended up highlighting a problem with the 12c hybrid histogram algorithm. It was a problem that I had mentioned in passing a few years ago, but only in the context of Top-N histograms and without paying attention to the consequences. In fact I should have noticed […]

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ORA-01466: Unable To Read Data – Table Definition Has Changed During Flashback

Mon, 15 Jan 2018 07:07:40 +0000

PROBLEM: While doing flashback a table to a prior timestamp, got below error. 11:20:45 SQL> FLASHBACK TABLE test2 TO TIMESTAMP TO_TIMESTAMP(‘2017-07-12 11:18:55’, ‘YYYY-MM-DD HH24:MI:SS’); FLASHBACK TABLE test2 TO TIMESTAMP TO_TIMESTAMP(‘2017-07-12 11:18:55’, ‘YYYY-MM-DD HH24:MI:SS’) * ERROR at line 1: ORA-01466: unable to read data – table definition has changed CAUSE & SOLUTION: This error happens when […]

ORA-14404: Partitioned Table Contains Partitions In A Different Tablespace

Mon, 15 Jan 2018 07:02:18 +0000

PROBLEM: While dropping a tablespace, got error ORA-14404. SQL> drop tablespace TEST_2 including contents and datafiles; drop tablespace TEST_2 including contents and datafiles * ERROR at line 1: ORA-14404: partitioned table contains partitions in a different tablespace CAUSE & SOLUTION: This error occurs when we try to drop a tablespace, which contains tables, whose partitions/subpartitions are […]

12c SQL loader express mode

Mon, 15 Jan 2018 06:34:25 +0000

In Oracle Database12c, SQL*Loader has a new feature called express mode that makes loading CSV files faster and easier. With express mode, there is no need to write a control file for most CSV files you load. Instead, you can load the CSV file with just a few parameters on the SQL*Loader command line. Example : […]

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good trick for changing password securly in oracle

Mon, 15 Jan 2018 05:56:24 +0000

Good information,    

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Using Zeppelin to Access MySQL

Sun, 14 Jan 2018 17:19:38 +0000

If you want to access MySQL Cloud Service using Zeppelin of Oracle Big Data Cloud Service Compute Edition (BDCSCE), you can use Spark DataFrames or Zeppelin interpreters. In this blog post, I’ll show how we can edit JDBC interpreter to connect MySQL Cloud Service. First login to Oracle Big Data Cloud console, and go to […]

Accessing Oracle DBaaS Monitor

Sun, 14 Jan 2018 13:18:18 +0000

Database deployments of single-instance databases on Oracle Database Cloud Service include Oracle DBaaS Monitor, a built-in monitor that provides a wide spectrum of information about Oracle Database and operating system status and resource usage. You can access Oracle DBaaS Monitor in the following ways: Using the “Open DBaaS Monitor Console” menu item Using a direct […]

Difference Between Virtual Index and Invisible Index

Sun, 14 Jan 2018 13:09:59 +0000

Virtual Index Virtual indexes allow us to simulate the existence of an index and test its impact without actually building the actual index. Only sessions marked for Virtual Index usage will be affected by their existence. Their creation does not affect new sessions. Virtual indexes will be used only when the initialization parameter “_use_nosegment_indexes” is […]

Virtual Index or Fake Index in Oracle

Sun, 14 Jan 2018 12:47:13 +0000

Oracle has come up with a feature called virtual index in oracle 9i. This feature allow us to test an index on a table without actually adding an index on the table. The table will be visible only in our session and will be used by our queries only (if optimizer decide it to use). […]

Anyone can be a developer – logic apps from Azure

Sat, 13 Jan 2018 21:12:00 +0000

As we go further and further down the rabbit hole that is Azure it becomes more and more apparent how good the platform is. However logic apps takes that to a whole new level - anyone can develop useful code with this - it's amazing (and this is coming from a very cynical 20 year […]

KeePass 2.38

Fri, 12 Jan 2018 08:29:30 +0000

Just noticed a KeePass 2.38 was released a few days ago. You can download it here. You can read about how I use KeePass and KeePassX2 on my Mac, Windows and Android devices here. Cheers Tim… KeePass 2.38 was first posted on January 12, 2018 at 9:29 am.©2012 "The ORACLE-BASE Blog". Use of this feed is for personal non-commercial […]

Clone a table

Fri, 12 Jan 2018 06:38:53 +0000

Sometimes doing a CREATE TABLE AS SELECT is all we need to copy the data from an existing table.  But what if we want more than that ?  What if we really want to clone that table to match the original as closely as possible.  We had a question along these lines on AskTOM today.  […]

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Secret Hacking Session: Oracle Background Process Communication, Exotic Wait Events and Some Tracing too

Thu, 11 Jan 2018 20:34:51 +0000

Since I’m running my Advanced Oracle Troubleshooting Training in the end of this month, I’ll do one of my “secret” hacking sessions too for promotion and noise-making reasons next week! ;-) Secret Hacking Session with Tanel Poder: Oracle Background Process Communication, Exotic Wait Events and Some Tracing too In this session we will look into […]

ASSM tangle

Thu, 11 Jan 2018 17:35:19 +0000

Here’s a follow-on from Tuesday’s (serious) note about a bug in that introduces random slowdown on large-scale inserts. This threat in this note, while truthful and potentially a nuisance, is much less likely to become visible because it depends on you doing something that you probably shouldn’t be doing. There have always been problems […]

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Hash Join Overflow Cost Formula #1

Thu, 11 Jan 2018 15:02:00 +0000

IntroductionThe Hash Join join method was introduced in Oracle version 7 (7.3 specifically I believe), and one of its main goals was to be a method that lent itself well to being parallelisable. However, it is such an efficient join method for larger data volumes even in serial execution that it is often picked by […]

Enterprise Manager and Firewalls

Wed, 10 Jan 2018 22:52:50 +0000

Just a short post, since this is a fairly common question I see. This morning someone asked me a question about Enterprise Manager and firewalls. They have an environment with EM targets placed in different zones / networks – with firewalls between. In the documentation, it states “Each Management Agent is configured to upload data […]

The Future of the DBA, #C18LV, Video 1

Wed, 10 Jan 2018 16:06:16 +0000

I’m starting to move towards doing more videos and hope to improve my video skills, (and maybe add a dance sequence, ya know, like the hip kids…)  Check out this post and please, do add comments, ask questions or just tell me what you think? Have an awesome Wednesday and no, don’t comment on my […]

Why I picked Postgres over Oracle, part II

Wed, 10 Jan 2018 16:04:47 +0000

Continuing this short series of blog posts on some of my drivers for moving to Postgres from Oracle. Please do read Part I of the series if you have not done so. It discussed the topics “History”, “More recently” and “The switch to Postgres”. Realization In the last months, discussing Postgres with my Oracle peers, […]

ASSM Argh 2

Wed, 10 Jan 2018 13:24:16 +0000

After yesterday’s post one of the obvious follow-up questions was whether the problem I demonstrated was a side effect of my use of PL/SQL arrays and loops to load data. What would happen with a pure “insert select” statement.  It’s easy enough to check: rem rem Script: assm_argh2.sql rem Author: Jonathan Lewis rem Dated: Jan […]

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ASSM argh!

Tue, 09 Jan 2018 17:53:13 +0000

Here’s a problem with ASSM that used to exist in older versions of Oracle had disappeared by and then re-appeared in – disappearing again by It showed up on MoS a few days ago under the heading: “Insert is running long with more waits on db file sequential read”. The obvious response […]

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pdb_to_apppdb.sql returns ORA-65021- A workaround

Tue, 09 Jan 2018 07:26:21 +0000

RSS content While exploring Oracle Multitenant Application Containers, I learnt that in order to convert a regular PDB  to an application PDB Clone a regular PDB  into an application root Connect to the cloned  PDB and execute the $ORACLE_HOME/rdbms/admin/pdb_to_apppdb.sql to convert the cloned regular PDB  to an application PDB However, when I connected to cloned PDB remotely using @… and executed the script pdb_to_apppdb.sql, I […]


Tue, 09 Jan 2018 04:16:00 +0000

Dear Friends,In 2018, we are very pleased to announce the upcoming new Oracle 12c Release 2 Performance Tuning Workshop.  This will be conducted by my friend Gavin Soorma who is an Oracle ACE Director, Oracle Certified Master,  and a highly experienced Oracle technology instructor.Oracle 12c Release 2 Performance Tuning Workshop:Course Duration: 20+ hours. This webinar […]

How to cancel SQL statements and disconnect sessions in #PostgreSQL

Mon, 08 Jan 2018 18:29:15 +0000

In PostgreSQL, you can cancel problem statements or terminate offending sessions remotely with PG_CANCEL_BACKEND and PG_TERMINATE_BACKEND. This article shows how you can do it with working examples. edb=# select current_database,current_user; current_database | current_user ------------------+-------------- edb | enterprisedb (1 row) I’m connected as superuser. The demo is done with EDB Postgres Advanced Server 10.1.5 but the […]

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MobaXTerm 10.5

Mon, 08 Jan 2018 14:50:57 +0000

I just noticed MobaXTerm 10.5 was released yesterday. The downloads and changelog are in the usual places. I love this tool. So much better than using Putty and/or Cygwin individually. Cheers Tim… MobaXTerm 10.5 was first posted on January 8, 2018 at 3:50 pm.©2012 "The ORACLE-BASE Blog". Use of this feed is for personal non-commercial use only. If you are not […]

Secure Erase of an Exadata System

Mon, 08 Jan 2018 13:01:39 +0000

What has to be done when the Lifecycle of an Exadata System comes to the end. You need to do an secure erase of DB and Storage nodes. By the way you can also secure erase the Switches and PDU, etc. but this is not described in this article. Documentation and  My Oracle Support […]

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KILL! KILL! KILL! (of Unix processes)

Mon, 08 Jan 2018 13:00:00 +0000

The start of this isn’t my post – I got it from here: but I wanted to reblog/repost and enhance it because as far as I can tell, 99% of all known DBA’s only use kill -9 to remove unhappy processes. Original Post: Useless Use of Kill -9 form letter No no no. Don't use kill […]

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Concurrent program migration

Mon, 08 Jan 2018 07:18:57 +0000

If your developer asked you to migrate concurrent program from dev or UAT to production, As a system administrator you need to do follow steps   Example : Concurrent Program : Concurrent program name : XX Report for Statement Shortcut : xx_rep_stat Application : XX Custom Application   XML Publisher : Data definition code : xx_rep_stat […]

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Unable to See the Legal Entity List of Values in the Bank Account Owner Field

Mon, 08 Jan 2018 06:09:25 +0000

A user was tried to select the legal entity list of values in the bank account, It does not appear in LOV.   Solution : you can review the below support document R12: CE: Unable to See the Legal Entity List of Values in the Bank Account Owner Field (Doc ID 415529.1) Note:  I selected […]

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Licensed for Advanced Compression? Don’t forget the network

Mon, 08 Jan 2018 01:50:35 +0000

We often think of Advanced Compression being exclusively about compressing data “at rest”, ie, on some sort of storage device.  And don’t get me wrong, if we consider just that part of Advanced Compression, that still covers a myriad of opportunities that could yield benefits for your databases and database applications: Heat maps Automatic Data […]

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ORA-01017: invalid username/password ora_dba group

Sun, 07 Jan 2018 11:24:37 +0000

C:\Users\mazar>sqlplus / as sysdba SQL*Plus: Release Production on Sun Jan 7 14:15:59 2018 Copyright (c) 1982, 2016, Oracle. All rights reserved. ERROR: ORA-01017: invalid username/password; logon denied   Solution: added ora_dba group to user C:\Windows\system32>net localgroup C:\Windows\system32>net localgroup ora_dba mazar /add The command completed successfully.   C:\Users\mazar>sqlplus / as sysdba SQL*Plus: Release Production […]

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RMOUG Training Days 2018 early registration deadline rapidly approaching

Fri, 05 Jan 2018 16:02:33 +0000

The deadline for early registration for RMOUG Training Days 2018 is rapidly approaching. The deadline is January 12. The early registration fee is $385 for RMOUG members and $450 for non-members. There is a packed agenda over the three-day event. The hotel costs are reasonable at $159/night which is very good compared to the hotel prices at the vendor […]

Oracle Database 18c is NOT an Autonomous Database! (Update)

Fri, 05 Jan 2018 09:53:16 +0000

Yesterday’s rant about the bad reporting of Oracle 18c got quite a lot of attention, but it seems the reaction from some people was a little odd IMHO. I wrote some updates to the post during the day, but I would just like to address them here to hopefully make a few things clear. Who […]

More Fun With sed

Fri, 05 Jan 2018 02:33:11 +0000

Objective is to convert what looks to be Samba share from Windows to Linux current directory path. Basically, the core of the code using sed. sed -i.bak -e 's|C\:\\\\scripts|'"$PWD"'|g' -e 's|\\\\|\/|g' "$f" [vagrant@db-asm-1 ~]$ pwd /home/vagrant [vagrant@db-asm-1 ~]$ [vagrant@db-asm-1 ~]$ ll total 8 -rw-rw-r-- 1 vagrant vagrant 56 Jan 5 03:22 t.1 -rw-rw-r-- 1 vagrant […]

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Its Cloud Service, Not Oracle 18c RDBMS which is Self-Driving and Autonomous

Thu, 04 Jan 2018 23:28:00 +0000

Look at the following picture displayed at Oracle's official website here, and you would forgive anyone who would naively believe that the Oracle 18c is a self-driving, autonomous database.Now, in above mentioned article after reading the title and the first paragraph, one still maintains the notion that Oracle 18c is autonomous and self-driving database. Its […]

DATA MASKING on EBS 12.1.3 with Enterprise Manager

Thu, 04 Jan 2018 07:54:31 +0000

Please follow the step by step document of Data masking on EBS 12.1.3 DATA MASKING on EBS 12

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Importing Into Existing Tables

Wed, 03 Jan 2018 16:15:49 +0000

I did some testing with impdp for a client. They asked me to write a procedure to import a set of tables from a production environment to a testing database. The import will include only a few tables, but not all, and will be performed to an already existing test environment that contains a full […]

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Reading AWR Reports #2 – Report Overview

Wed, 03 Jan 2018 15:10:00 +0000

In the first post on Reading AWR Reports I made the point that you should first be clear on the details of the "performance problem" you are investigating. If there is no specific problem reported then there is no point looking for something that is not there in an AWR report. I also stated that […]

find the files older than 30 days in linux

Wed, 03 Jan 2018 12:47:10 +0000

cd /u01/app/12c/oracle/trace find *.trc -maxdepth 1 -mtime +30 -type f -exec ls -l {} \;    

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Oracle Database 18c is NOT an Autonomous Database!

Wed, 03 Jan 2018 10:01:35 +0000

RANT WARNING! From the get-go Oracle has been talking about the Autonomous Database as a cloud service based on Oracle Database 18c, but I can’t remember them once saying Oracle Database 18c is an Autonomous Database. There is a reason for that. It’s because it isn’t. It’s not meant to be. It’s basically a big […]

Text me baby…..

Tue, 02 Jan 2018 13:47:00 +0000

This week I've been looking into the possibility of getting our monitoring system(s) to be able to send SMS alerts in the event of really critical problems - to try and prevent business outages or at least get us alerted ahead of the game before the business calls us out to tell us something isn't […]


Tue, 02 Jan 2018 08:43:07 +0000

Following on from a Twitter reference and an update to an old posting about a side effect of  constraints on the work done inserting data, I decided to have a closer look at the more general picture of default values and inserts. Here’s a script that I’ve tested against,, and (original install, […]

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Oracle Database 18c

Tue, 02 Jan 2018 07:00:40 +0000

Happy New Year 2018! We all have questions on Oracle Database 18c and its ability to self-drive! I tried to summarize my understanding of Oracle Database 18c and RU/RUR in a blog post here. What to expect in Oracle Database 18c I like the idea of releasing major features more frequently and releasing patches and […]

How Well a Query Optimizer Handles Subqueries?

Sun, 31 Dec 2017 21:52:35 +0000

At the beginning of December, at the UKOUG Tech17 conference in Birmingham (GB), I presented a comparison of the query optimizers of MySQL 8.0.3 and PostgreSQL 10.1. One of the things I talked about is their ability to handle subqueries. I summarized my findings with the following sentence: Simple sub-queries that are not correctly optimized […]

Been There

Sun, 31 Dec 2017 10:51:01 +0000

It’s the end of the year and time for a retrospective of some sort so I was thinking of listing the top 10 most popular pages on my blog, but Connor McDonald beat me to it, so I decided to see if I could remember all the countries I’d visited since starting to work with […]

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Oracle Tidbits – December 2017 #oratidbit

Sun, 31 Dec 2017 07:01:21 +0000

“Oracle *daily* TidBits” (#oratidbit) published on Facebook, Twitter, and Google+ during weekdays in December 2017. You will also see these tidbits, one tidbit at a time, for each page refresh on the right side of this blog as well… Hope you find these helpful to learn something new or to remind you of its existence and use. […]

It’s not about ego … it’s about knowledge

Sun, 31 Dec 2017 00:44:19 +0000

Take a quick look at this blog post by Jonathan Lewis Anyone that has been working with Oracle for any length of time probably knows that Jonathan has a great depth of knowledge in the Oracle database, and is a regular blogger.  But this post is a good example to inspire anyone that is […]

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Sat, 30 Dec 2017 12:08:43 +0000

Here’s an odd little quirk that appeared when I was playing around with default values just recently. I think it’s one I’ve seen before, I may even have written about it many years ago but I can’t find any reference to it at present. Let’s start with a script that I’ll run on (the […]

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Creating a database link using a tnsnames entry

Fri, 29 Dec 2017 16:06:23 +0000

I have had this in my draft posts for a couple of weeks and I refrained from publishing because it was too simple. However the main purpose of this post is to help others save time by providing useful information. The secondary purpose of to remind myself how I overcame whatever problem is being covered. […]

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You gotta work harder!

Fri, 29 Dec 2017 13:24:44 +0000

If I take a long hard look at the people *I consider* successful, the main thing I notice is they consistently work hard. They have focus and they put in a lot of hours to get what they want. It doesn’t matter what area it is, you can see the same thing time and time […]

Why I picked Postgres over Oracle, part I

Wed, 27 Dec 2017 16:07:46 +0000

As with many stories, if you have something to tell, it quickly takes up a lot of space. Therefor this will be a series of blog posts on Postgres and a bit of Oracle. It will be a short series, though… Let’s begin History  I have started with databases quite early on in my career. […]


Tue, 26 Dec 2017 15:18:21 +0000

Alert.log: New timestamp format in Oracle 12.2 Whats new with the timestamp format in Oracle 12c Release 2? UNIFORM_LOG_TIMESTAMP_FORMAT CANNOT BE SET ON ASM INSTANCE (Doc ID 2308274.1) It's expected behavior.  UNIFORM_LOG_TIMESTAMP_FORMAT parameter can't be set on ASM instance in It will be implemented in future release 18.1.

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Best plsql function ever…..?

Sun, 24 Dec 2017 20:07:00 +0000

Total clickbait title i know and this isn't likely to be the best formatted you'll ever see or the one that has the cleverest use of objects/arrays (i'll leave that to the real experts like Steven) but this is probably the function that i've developed i've been most pleased with - it pulls together a […]

The 12 Days of Database Christmas

Sun, 24 Dec 2017 14:43:45 +0000

My brain has a tendency to wake up way before everything else in the house, so I try to keep it occupied best I’m able without disturbing anyone.  This may explain why so many if my plans are well flushed out, as I have a tendency to hash them out in the early morning hours […]