Archive for the ‘Triggers’ Category

Triggers for Apache HBase

Wednesday, July 3rd, 2013

Cloudera Search over Apache HBase: A Story of Collaboration by Steven Noels.

Great background story on the development of triggers and indexing updates for Apache HBase by NGDATA (for their Lily product) and that underlies Cloudera Search.

From the post:

In this most recent edition, we introduced an order of magnitude performance improvement: a cleaner, more efficient, and fault-tolerant code path with no write performance penalty on HBase. In the interest of modularity, we decoupled the trigger and indexing component from Lily, making it into a stand-alone, collaborative open source project that is now underpinning both Cloudera Search HBase support as well as Lily.

This made sense for us, not just because we believe in HBase and its community but because our customers in Banking, Media, Pharma and Telecom have unqualified expectations for both the scalability and resilience of Lily. Outsourcing some part of that responsibility towards the infrastructure tier is efficient for us. We are very pleased with the collaboration, innovation, and quality that Cloudera has produced by working with us and look forward to a continued relationship that combines joint development in a community oriented way with responsible stewardship of the infrastructure code base we build upon.

Our HBase Triggering and Indexing software can be found on GitHub at:

https://github.com/NGDATA/hbase-sep
https://github.com/NGDATA/hbase-indexer

Do you have any indexing or update side-effect needs for HBase? Tell us your thoughts on this solution.

Triggers in MySQL

Monday, January 9th, 2012

Triggers in MySQL

From the post:

Almost all developers are heard about Triggers and all knows that mysql support triggers and triggers are adding an advantages to mysql.Triggers are the SQL statements are stored in database.

Triggers are the SQL statements which add functionality to your tables so that they perform a certain series of actions when a some queries are executed. We can say in easy language is Triggers are some conditions performed when INSERT, UPDATE or DELETE events are made in the table without using two separate queries.

Sometimes developers are prefer to use store procedures rather than triggers but triggers are one kind of store procedures which contain procedural code into body.The difference between a trigger and a stored procedure is that a trigger is called when an event occurs in a table whereas a stored procedure must be called explicitly.

Short overview of triggers in MySQL.

Possibly useful if you are using a relational backend for your topic map engine.

Should topic map engines support the equivalent of triggers?

As declared by a topic map?

Now that would be clever, to have a topic map carry its triggers around with it.

Admittedly, interactive data structures aren’t the norm, yet, but they are certainly worth thinking about.