What a cracking Oracle Midlands event!
The evening started with a session on “Designing Efficient SQL” by Jonathan Lewis. The first few slides prompted this tweet.
When someone asks me a question about SQL tuning my heart sinks. It’s part of my job and I can do it, but I find it really hard to communicate what I’m doing. Jonathan’s explanation during this session was probably the best one I’ve ever heard. Rather than trying (more...)
Normally, when I create physical standby database, the configuration has the same directory structures and name values as production with the exception of db_unique_name.
But this time was not the case as shown below.
ANGEL:(SYS@xmenstby):PHYSICAL STANDBY> show parameter name NAME TYPE VALUE ------------------------- ----------- ---------------------------------------- cell_offloadgroup_name string db_file_name_convert string /oradata/xmenprod, /oradata/xmenstby db_name string xmenprod db_unique_name string angel_xmenstby global_names boolean FALSE instance_name string xmenstby lock_name_space string log_file_name_convert string /oradata/xmenprod, /oradata/xmenstby processor_group_name string service_names string xmenstby ANGEL:(SYS@xmenstby):PHYSICAL STANDBY>
However when I went to start things up, ASM wasn't starting up, giving me these errors:
ORA-04031: unable to allocate 32 bytes of shared (more...)
A question came up on Oracle-L recently about possible locking anomalies with deferrable referential integrity constraints.
An update by primary key is taking a long time; the update sets several columns, one of which is the child end of a referential integrity constraint. A check on v$active_session_history shows lots of waits for “enq: TX – row lock contention” in mode 4 (share), and many of these waits also identify the current object as the index that (more...)
Last week I’ve gotten a question on how storage indexes (SI) behave when the table for which the SI is holding data is changed. Based on logical reasoning, it can be two things: the SI is invalidated because the data it’s holding is changed, or the SI is updated to reflect the change. Think about this for yourself, and pick a choice. I would love to hear if you did choose the correct one.
We went over a few of the Java “tuning” options last time, so let’s go onto the OMS tier for this post.
Location, Location, Location
High latency issues between the OMS(Service) and the OMR, (Repository) when separated by geographical location is common. It’s important when designing the Enterprise Manager environment that you keep your OMS hosts close to the repository hosts geo-locationally. Your agents can be global, with minor network considerations, but the (more...)
In my recent post I already mentioned it a little bit: Integrating your manual Data Guard Broker configuration in OEM Cloud Control can become a sort of climbing a Mountain. And it doesn’t have to be.
But first a short description of the situation. I have a working Data Guard broker configuration between two Cluster Databases running Oracle 22.214.171.124 on linux x86-64. Both clusters have an Cloud Control agent (126.96.36.199) (more...)
I wrote about the Code Based Access Control (CBAC) stuff in Oracle Database 12c a while back.
- Code Based Access Control (CBAC) : Granting Roles to PL/SQL Program Units in Oracle Database 12 Release 1 (12.1)
I’ve recently “completed the set” by looking at the INHERIT PRIVILEGES and BEQUEATH CURRENT_USER stuff for PL/SQL code and views respectively.
This post runs in parallel with a post I made 5 years ago and which is still the most read one on this blog
It will show how to reduce space taken up in the SYSAUX tablespace by because you have many more AWR snapshots being retained than you think.
Firstly lets take an example database and we can see that we are using 92Gb of space
set linesize 120 set (more...)
A few months ago I wrote about some MySQL on Oracle Linux migrations we were working through. It’s been a long time coming, but last weekend was the go-live for this batch of migrations. So far so good!
Most of the elapsed time since my last post on this subject has been spent with the developers and users testing the migrations.
The process has taken a bit longer than some people would have liked. Rather (more...)
One of my clients has been running an Oracle RDB database on VMS for decades.
This RDB database stores mission critical data and interfaces with COBOL applications and Oracle 8i databases.
(If you wonder what RDB is; it’s a RDBMS created by DEC in 1984 and bought by Oracle in 1994)
While modernizing the IT landscape, the client expressed the desire to reduce complexity and migrate the mission critical data in RDB to an Oracle (more...)
Performing an rm -rf operation is normally a simple operation albeit risky if you are in the wrong folder. However within ASMCMD there are a couple of bugs associated with it.
Here are two examples and workrounds
FRA full - warning in the alert log - action needs to be taken - this is an 188.8.131.52 database on OEL (5.8)
ORA-19815: WARNING: db_recovery_file_dest_size of 10484711424 bytes is 100.00% used, and (more...)
A week ago, Oracle released Oracle SOA Suite 12c. In this blog I will show how easy it is to create a Standalone-server environment for Oracle Event Processing (OEP) 12c.
The major new features of Oracle Event Processing 12 are the new integrated development environment based on Jdeveloper and the Event Delivery Network (EDN) event adapter nodes which provide that tight integration at runtime to SOA Suite composites and all other SOA components supporting the (more...)
Here’s a thread from Oracle-L that reminded of an important reason why you still have to hint SQL sometimes (rather than following the mantra “if you can hint it, baseline it”).
I have a query that takes 77 seconds to optimize (it’s not a production query, fortunately, but one I engineered to make a point). I can enable sql plan baseline capture and create a baseline for it, and given the nature of the (more...)
A week ago, Oracle released Oracle SOA Suite 12c. In this blog I will show how easy it is to create a SOA Suite development environment.
The Oracle SOA Suite 12c Quick Start distributions allow you to quickly install a development or evaluation environment on a single host computer. It only takes a couple of minutes to set it up.
Before starting the installation, make sure that you have a working Java Development (more...)
This is a quick response to a question on an old blog post asking how you can adjust the high value if you’ve already got a height-balanced histogram in place. It’s possible that someone will come up with a tidier method, but this was just a quick sample I created and tested on 184.108.40.206 in a few minutes. (Note - this is specifically for height-balanced histograms, and it’s not appropriate for 12c which has introduced (more...)
Wither you use a single OEM and migrating to a new OEM or have multiple OEMs, the need to move templates between environments will arise. I had this exact problem come up recently at a customer site between an OEM 11g and OEM 12c. In order to move the templates, I needed to export the multiple monitoring templates using EMCLI. The command that I used to do individual exports was the following:
./emcli export_template -name="<template (more...)
Well, this blog posting is not about explaining the (more...)