Search

Top 60 Oracle Blogs

Recent comments

Pythian

Log Buffer #422: A Carnival of the Vanities for DBAs

This Log Buffer Edition picks, choose and glean some of the top notch blog posts from Oracle, SQL Server and MySQL.

Oracle:

OpenTSDB and Google Cloud Bigtable

Data comes in different shapes. One of the these shapes is called a time series. Time series is basically a sequence of data points recorded over time. If, for example, you measure the height of the tide every hour for 24 hours, then you will end up with a time series of 24 data points. Each data point will consist of tide height in meters and the hour it was recorded at.

OEM 12c Silent Installation

“What’s for lunch today?”, said the newly born ready to run Red Hat 6.4 server.

“Well, I have an outstanding 3-course meal of OEM12c installation.
For the appetizer, a light and crispy ASM 12c,
DB 12c with patching for the main and desert, and to cover everything up, OEM 12c setup and configuration”, replied  the DBA who was really happy to prepare such a great meal for his new friend.

“Ok, let’s start cooking, it won’t take long”, said the DBA and took all his cookware (software), prepared ingredients (disk devices) and got the grid infrastructure cooked:

Log Buffer #421: A Carnival of the Vanities for DBAs

As always, this fresh Log Buffer Edition shares some of the unusual yet innovative and information-rich blog posts from across the realms of Oracle, SQL Server and MySQL.

Oracle:

A developer reported problems when running a CREATE OR REPLACE TYPE statement in a development database. It was failing with an ORA-00604 followed by an ORA-00001. These messages could be seen again and again in the alert log.

Linux HugePages for Oracle on Amazon EC2

One of the optimizations available to us when running Oracle on Linux is huge page support. This feature of the Linux kernel enables processes to allocate memory pages of size 2M (instead of 4k). In addition, memory allocated using hugepages is pinned in physical memory. It cannot be swapped out.

It is now common practice to enable huge page support for Oracle databases with large SGAs (one rule of thumb is 8G). Without this feature, the SGA can be, and often is, paged out. Paging out portions of the SGA can result in disastrous consequences from a performance standpoint. There are a variety of load patterns that perform particularly poorly without hugepages. Running with large numbers of processes, sudden increases in processes (connection storms), and highly concurrent access of diverse sets of SGA pages all can bring an Oracle system without hugepages to its knees.