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Batch Insert/Update for Mysql in Java

Large inserts/Updates are a costly operation. One foolish way that I used to do is to run each update or insert query one at a time. Its incredibly slow. With most of the systems currently the latency is what is killing the performance not the CPU. Hence l …

More than 100% CPU in top in Linux/Mac

If you are power linux/mac user you should have noticed at least once that top shows more than 100% CPU for a process. I also have seen this multiple times but always wondered how it can be. Here is an example of how my top looked when I started my java an …

Enable Multiple Login in Same Account in Gmail

Gmail recently started merging its App accounts to Gmail. Hence you wont be able to login into both the accounts in the same browser now. Here is a way on which you can still do it. This can be done for people who have multiple gmail accounts and want to b …

User Level Threads

User level threads is created for light weight threads. It needs to be controlled, context switched and swapped by the process. To the Operating System it is only one process without any threads. Here is one implementation of it: q.h [c] #includ …

Service Engineer/System Administrator Interview Questions

This is not my code alone.  It was the group effort of Vivek Ram, Cijo George, Sandeep Unni and mine during our epic preparation for Yahoo!. I am just putting it open for others who would be looking for this information. Convert all lower case to up …

Ontology Linked Data

The following is a Assignment on Ontology and Linked Data and the evolution of data which lead to the use of ontology in web. Thanks to my teammates Bharath Gowda and Sravani Thota for working on the same. Ontology And Linked Data An ontology for …

Important MySQL DBA Interview Questions

Here are a few sets of interview questions expected for MySQL DBA position.These are compilation of the usual questions from various DBA texts: What is Log Switch? – The point at which ORACLE ends writing to one online redo log file and begins writin …

Display row number in Mysql Select Query

How many times did want to have the row number or the position of the row in the selected query? I had many cases where I needed this feature. I needed the feature for printing the rank of a person where each row is the mark of the person. So lets see how  …

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