If you are an RDBMS person that is used to joining data from tables, you will be happy to know that this capability exists in Pig. Below is a very simple example. grunt> fs -cat /people 1,1,steve howard 2,1,becky howard…
ATG RepeatingRequestMonitor
During a recent period of high traffic level on our site, we found we had several threads blocked on a particular component. We found that the component contained a synchronized block of code, which means only one request can be…
Inserting full objects into a database column
I have never seen the need for this, but I like to understand things in case I ever run across them “in the wild”. I did see it in a commercial ecommerce application in which the designers serialized an “Order”…
Cloudera Impala simple command line test
I am a big believer in simple command line examples. Connecting the dots is so much easier when you do this. There will be much more on this, but this should get you started. CLASSPATH is shown below. The absolute…
Querying Hive from Tomcat
Below is a very simple example to get started on how Hive can be queried from a web front end. The idea behind this would be to present the user with a csv file mime type that would be opened…
Querying Hadoop from Tomcat
Below is a very simple example for how to print in Tomcat the contents of a file stored in HDFS. I am not entirely sure where this would be useful, for the following reasons: * Unless you have a list…