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Oracle EM : connect to database broken

#555555;">OEM just seems to have too many brittle esoteric configuration files and process dependencies. Ideally I just want to connect with system/password and go. Is that too simple to ask for?

#555555;">Today I tried out OEM and got the general broken page:

#555555;">#2970a6;" href="">

#555555;">And my first reaction was just to give up and move on, but then I noticed the error message sounded some what simple:

#555555;">ORA-28001: the password has expired (DBD ERROR: OCISessionBegin)

#555555;">Hmm, maybe this *is* easily fixable. Well guess again. Luckily someone has well documented the fix

Oracle’s SQL Tuning pack, part III

#555555;">How does the STA work in 11gR2 with the query from “Oracle’s SQL Tuning Pack – part II″ ?

#555555;">In Part II, the STA in 10g proposed a new profile for the query but that profile actually caused the query to run slower. Quetion is, in 11gR2 does the STA do better?

#555555;">Below I ran the query load, identied the query, submitted to STA and STA spent 30 minutes burning CPU trying to tune the query and finally ended with an error that a better plan could not be found.

Oracle’s SQL Tuning pack, part II


Hadoop as a Cloud

The idea of clouds “meeting" big data or big data "living in" clouds isn’t simply marketing hype. Because big data followed so closely on the trend of cloud computing, both customers and vendors still struggle to understand the differences from their enterprise-centric perspectives. Everyone assumes that Hadoop can work in conventional clouds as easily as […]

More Than Just a Lake

Data lakes, like legacy storage arrays, are passive. They only hold data. Hadoop is an active reservoir, not a passive data lake. HDFS is a computational file system that can digest, filter and analyze any data in the reservoir, not just store it. HDFS is the only economically sustainable, computational file system in existence. Some […]

Hadoop is Not Merely a SQL EDW Platform

I was recently invited to speak about big data at the Rocky Mountain Oracle User's Group. I presentedto Oracle professionals who are faced with an onslaught of hype and mythology regarding Big Data in generaland Hadoop in particular. Most of the audience was familiar with the difficulty of attempting to engineer even Modest Data on […]

20th Century Stacks vs. 21st Century Stacks

In the 1960s, Bank of America and IBM built one of the first credit card processing systems. Although those early mainframes processed just a fraction of the data compared to that of eBay or Amazon, the engineering was complex for the day. Once credit cards became popular, processing systems had to be built to handle […]

Oracle’s SQL Tuning pack, part I

#555555;">Have you used Oracle’s SQL Tuning Pack? What were your experiences like?
At my last consulting gig 2 out 3 statements I “tuned” with the SQL tuning pack actually ran significantly more slowly after applying the profiles recommended. I thought it was just my bad karma and luck of the draw until recently. Recently I’ve started asking other DBAs what their experiences were and generally finding less than enthusiastic responses. In the classes on Oracle 10g and OEM, I’ve always cautioned that profiles should not be blindly trusted and give an example using a Swingbench query where the SQL runs more slowly after the profile.If applying the profile, I recommend to jump immediately to the SQL performance page and to verify the effect of the profile on the load of the query.

It’s Not About the Snapshot

I hear this from time to time:

“Can’t I create a database copy in seconds with a file system snapshot?”

First let’s take a step back. There is a huge need to clone database quickly, easily and with as little resource as possible for development, QA, UAT, debugging, reporting and backup yet hardly any of the industry uses file system snapshots for cloning. Cloning with file system snapshots has been a possibility for almost 20 years.    Why, if there is a solution to a huge problem, is no one using it? Because it requires specialized hardware, storage system experts coordinating with DBAs and system admins and a lot of scripting. (Unless using Delphix)

Database Thin Cloning: Allocate on Write (ZFS)

#555555;">Allocate on Write Thin Cloning

#555555;">Three challenges specifically stand out when considering Copy on Write filesystem snapshots described in the previous section:

  • The number of snapshots you can take of source database LUNs is limited
  • The size of the snapshots is limited
  • Difficulties arise sharing the base image of source databases at multiple points in time. In some cases it is not possible, in others difficult or resource heavy.

#555555;">These challenges highlight a specific need: to create thin provision clones of a source database from multiple points of time at the same time without using any additional space consumption. This requirement is important, as it allows one base image to serve as the foundation for all subsequent clones and imposes no unplanned storage or refresh requirements on users of the target (cloned) systems.