Original Post can be viewed at 12c:Limiting PGA with pga_aggregate_limit
This is a interesting feature for Oracle DBA’s. Till now there has been no way of limiting total PGA being used by oracle instance. _pga_max_size (hidden parameter) could be used to limit per process memory. SGA_TARGET used to be hard (more...)
So there is a new toy in the market for database geeks : Oracle has released database 12c. Every social platform is abuzz with the 12c activity. So thought that I should also complete the ritual
In this post Aman has already summed up many important links.
Maria Colgan has (more...)
It's not often that I run across articles that really resonate with me. Last night was one of those rare occasions. What follows is a sampling of what I consider to be required reading for any IT professional with a slant towards database development.
Install the Oracle Database Gateways 11g R2 (11.2). See the screen snapshots of the installation here.
- During the installation, the following default initialization parameter file is created:
dg4msql = Database gateway for Microsoft SQL Server.
If you choose a different database option, (more...)
When to consider sharding a MySQL database
Why should you not just design your applications from the start to account for data sharding? Sharding a database, that is horizontally partitioning tables among multiple databases, creates an added level of complexity that is not desirable in an application. However, there are times when sharding is required to maintain acceptable performance. So when is the right time to shard your database?
When to consider sharding a MySQL database Why should you not just design your applications from the start to account for data sharding? Sharding a database, that is horizontally partitioning tables among multiple databases, creates an added level of complexity that is not desirable in an application. However, there are times when sharding is […]
Schemas and users are frequently used interchangeably as if they were the same thing. For the most part, that's ok. In Oracle the concepts are so tightly coupled that thinking of them as the same thing is not really that far wrong.
In reality, a user is a database account that is given a password and permissions. A schema is a container, or namespace, for containing schema objects. Schema objects are things like tables, views and indexes.
In Oracle, when a us
The LAST_REFRESH_DATE column of the DBA_MVIEWS or the LAST_REFRESH column of the DBA_MVIEW_REFRESH_TIMES indicates the start refresh time. But what if we’d like to find out how long the refresh of the materialized view really takes. Well, we can query the DBA_MVIEW_ANALYSIS.
For Complete Refresh, the refresh duration will be in the FULLREFRESHTIM column of the DBA_MVIEW_ANALYSIS. For Fast Refresh duration, it will be in the INCREFRESHTIM column.
Both values are in seconds.
SELECT mview_name, last_refresh_date, fullrefreshtim, increfreshtim
MVIEW_NAME LAST_REFRESH_DATE FULLREFRESHTIM INCREFRESHTIM
------------------------ ---------------------- -------------- -------------
MV_CHANGE_HISTORY 07-JAN-13 04.36.58 PM 0 (more...)
An Oracle Database appliance is a set of standard hardware and software molded together to created a 2 node RAC cluster that is easy to deploy. In parts 1 & 2 i talked about what methods you can use to reformat or erase the Oracle Database Appliance and rebuild it. (more...)
There are occasions when you recieve a complete backup of a database from a place different then yours and have to do a restore. normally a restore is simple . put the files in a directory run rman catalog on them and you are done. but what if you have rman (more...)
Oracle Real Application Cluster (RAC) becomes the technology of choice for highly available and highly scalable deployment of enterprise Oracle database environment. With its innovative technology it comes with no surprise its complexity. The complexity is not only with the underlying database technology itself, but also how well you design and implement it to work with other components including operating system, storage subsystem, etc. In order to setup and maintain a successful RAC environment, it not only requires technical knowledge of database administrator (DBA), but also well collaboration and extended planning between all IT and business partners.
Few years (more...)