Topic: This post describes a data pipeline for a machine learning task of interest in high energy physics: building a particle classifi
These last days I've been playing with Apache Tomcat 9 and log4j2. You may wonder why I want to change the good an old Tomcat JULI. Well, although I love the simplicity of its configuration and the fact that JULI works, log4j2 offers a big variety of appenders that make it very interesting. Also I prefer the way of how log4j2 rolls the files, keeping the original name un-touched (e.g.
Topic: This post dives into the steps for deploying and using a performance dashboard for Apache Spark, us
Usually when you are developing a new feature or fixing an issue, you want to focus in your business logic. If your application delegates the authentication in some SSO system you usually mocks the response from this last one. However for integration tests, it is nice to be able to test your application against the full SSO cycle, specially if you have to use things like the SAML2 Web Profile.
Virtual Private Databases (VPD) is an Enterprise Edition feature related to security. It restricts the scope of Data Manipulation Language to a subset of the table rows by transparently adding a where clause before executing them. It is also called Row-Level Security (RLS). Where the policy is enabled, it is like having the selected DML (SELECT, INSERT, UPDATE, DELETE) operate on a transcient view. And the predicates for this view can be dynamic and even query tables that the user cannot see.
The Oracle Database software is large, several gigabytes in Oracle Home for the part that is deployed on the operating system, and additional megabytes in SYSTEM tablespace for the part that is deployed as stored procedures (mainly the dbms_% packages). And this is not a problem with the traditional deployment methods where you can have a .zip golden image of the Oracle Home, and a database template to start a new DB. But this monolithic approach is not adapted to the current way people want to deploy software:
In this post, I will be talking about my openlab project and internship experience.
CERN Openlab Summer Project: Achieve a 0-downtime CERN Database infrastructure
My project was about evaluating, comparing and testing Oracle Ksplice with Red Hat Kpatch.
Do you have tables with a column storing filenames? Long filenames with full path? If this is the case, then you probably realized how an index on this can be large. And when looking at the values sorted, you have seen the inefficiency of it: a big part of the full name is reapeated because it has the same prefix for files in the same (sub)directory. The 12cR2 Advanced Index Compression (COMPRESS ADVANCED LOW) does not help here because it only compresses identical values, like the basic compression of tables. With unique filenames, we cannot expect any benefit.
There are not many ways to access efficiently to table rows. Either you want lot of them, because your predicate is not very selective, and you read the whole table in the fastest you can do. This is Table Full Scan. Or you use a structure that gives you access to the subset of rows you need. There are mostly two structures for that: sort and hash.
This post will walk through the different remote server's JMX and local monitoring client SSL connection possibilities.