In our Remote DBA practice, we frequently perform comprehensive system reviews for our customers on their database services. Among the things we always check for are non-default settings for the database software. We want to validate that any non-default setting is set that way for a good reason, and that any setting that is default really should … [Read more...]
Amazon RDS for Oracle: First Impressions
On Tuesday, Amazon announced availability of an Oracle version of their Relational Database Service (RDS). RDS is one of Amazon’s cloud services. You can think of it as ”database as a service.” Amazon provides a running database, storage, horsepower and a variety management tasks. And all you have to do is store you data in it. … [Read more...]
Determining optimal Amazon S3 transfer parallelism
Amazon’s Simple Storage Service (S3) is a robust, inexpensive and highly-available internet data storage service. At Blue Gecko, we occasionally help our customers design and implement S3-based backup strategies. Compared to conventional off site tape vaulting services, the advantages of vaulting database and other backups to S3 are many. … [Read more...]
EC2 outage reactions showcase widespread ignorance regarding the cloud
Amazon EC2′s high-profile outage in the US East region has taught us a number of lessons. For many, the take-away has been a realization that cloud-based systems (like conventionally-hosted systems) can fail. Of course, we knew that, Amazon knew that, and serious companies who performed serious availability engineering before deploying to … [Read more...]
Oracle tablespace hot backup mode revisited
Here’s a revised version of an old popular article I wrote over ten years ago. I wrote this when I was at Amazon.com, long before I came to work at remote DBA provider Blue Gecko. Enjoy! Oracle’s pre-RMAN hot backup mode is the subject of one of the most pervasive and persistent misconceptions about Oracle. During an Oracle tablespace … [Read more...]
YPDNGG: You Probably Don’t Need Golden Gate
Before launching into this, I must give due deference to Mogens Nørgaard’s landmark article, You Probably Don’t Need RAC (YPDNR), available here, but originally published Q3 2003 in IOUG Select Journal. Mogens showed that you can be a friend of Oracle without always agreeing with everything they do. At Blue Gecko, many of our remote … [Read more...]
How I got access to My Oracle Support (MOS) for US$2.67
Oracle professionals know that the two main sites for information and support on running Oracle products are the Oracle Technology Network (OTN), and My Oracle Support (MOS). OTN is free for anyone, and provides discussion forums, white papers and free base-release software downloads under the Developer License. MOS requires a paid software … [Read more...]
Report from Oracle Openworld
Openworld 2010, despite the supposedly lagging economy, had record attendance again this year. No doubt this was the result of Oracle acquiring something like fourteen companies since last year, including Sun in 2009. The crowds were thick, divided about evenly between geeks in badly-fitting vendor t-shirts and slick sales-side hustlers with … [Read more...]
A Cloud over San Francisco for OpenWorld 2010
Oracle OpenWorld 2010 is just bursting with big cloud-related announcements this week. As I prepare to present on the Amazon cloud at OOW2010 on Thursday (http://bit.ly/aSKdIQ), I thought I would highlight two of the biggest cloud-related announcements of the week. Exalogic We all know about Exadata, Oracle’s hardware-based storage-optimized … [Read more...]
Finding thread IDs and names of SQL Server background threads
In Microsoft SQL Server, session IDs of 50 or less are dedicated background threads. These are analogous to Oracle’s background processes. Suppose you needed to obtain the Windows thread ID of a SQL server background thread. Just try finding out how to do that in the Microsoft documentation or by Googling. I tried, and came up … [Read more...]
Good OCP / bad OCP
For those contemplating launching a career in Oracle database administration, there are essentially three routes: Oracle education and certification (OCP) Third-party educational programs (University and private training) Self-directed study and experimentation Most entering into the field assume that to be employable, they must become an Oracle … [Read more...]
How Incompetence Stimulates the Information Technology Economy
As information technology professionals, we constantly complain about mismanaged projects in which we have the misfortune to be involved. Frequently, someone with more power than knowledge – usually in management and under the sway of a persuasive vendor sales team – has come up with a systems design most politely described as novel. Because of … [Read more...]
Converting Hexadecimal Oracle SCNs to Decimal
Oracle serializes transactions and manages concurrency and recovery using an ever-increasing number called a system change number, or SCN. Usually, we see these numbers expressed in decimal, in places like the v$ views and the alert log. Occasionally, however, Oracle's code expresses SCNs in hexadecimal. Unfortunately, you can't just perform a … [Read more...]
ORA-00054: resource busy and acquire with NOWAIT specified
When trying to perform DDL such as truncate, drop or alter on Oracle objects that are in use by other users, you may encounter the error ORA-00054: resource busy and acquire with NOWAIT specified. This occurs even if you acquire an exclusive DML lock on the table using lock table. Locking a table does not guarantee the success of any subsequent DDL … [Read more...]
ORA-00600 [kkojcio]
According to Oracle Support note 336315.1, this ORA-600 error is a known issue (bug 4335559) affecting some versions of 9i and 10g. It is a bug in the cost-based optimizer's initial join order routine. The note mentions a simple known workaround that you can implement either in one session, or throughout the whole Oracle instance. To implement … [Read more...]