Hp Vertica

So you probably know that I have been working with HP’s Vertica. I’m very glad that I had this opportunity to interact with something like this. The technology behind it is pretty new and immature and lacks the power of PL/SQL but the speed that it achieves through massive parallel execution of queries is simply amazing. I don’t know if you have heard of the term K-Safe or K-Safety. When I first heard it, I had no idea what it was. Then after going through some of the documentation I kind of got the point. ...

Hey there, I guess you have been having a lot fun with your Vertica databases. I thought I’d share some of the things that I did to improve my query performance. Tables and Projections in Vertica In Vertica even though we access data through tables everything is stored in projections which are stored among nodes in various ways depending on the K Safety and the Segmentation options that we choose when creating the table. We can make modifications to these projections manually or run the Database Designer to generate projections for us. Sometimes to get the best performance we have to write query specific projections. ...

Vertica has a special feature to join tables and fill in the last available values where values would otherwise be null. I had a similar use case and wanted to test how I could make the best use of it. I played with simple examples and got it right, but with a slightly more complex one, I was stuck or maybe I just couldn’t understand what was happening. So I posted a question at Stackoverflow ...

I had a problem creating a table with just SQL that is supported by Vertica. Most of the solutions that I came across online were using procedures. But after a lot of playing around and reading vertica documentation I found a solution to my problem. read more about the problem and the solution at Stackoverflow

Hey there! So you use Vertica and vsql to interact with your tables. Ever had those times when you wanted to take stuff from your table and paste it into Microsoft Excel for sending it off to someone not so technically acquainted with Vertica? You could write a script to do that for you. But if you just had to do it within a vsql session you also have options to do it. ...

My colleague had an issue in Vertica. He had a set of values in table 1 to be deleted based on the records in a table table2. I didn’t think this would be easy considering VERTICA didn’t support joins when doing deletes unlike MYSQL. But they do have something else. Let me take you through the steps I followed. I created the following table in which I have records create table eakan (sec\_id int, nameid int, date date); insert into public.eakan values(1,1,'2013-05-20'); insert into public.eakan values(2,1,'2013-05-20'); insert into public.eakan values(3,1,'2013-05-20'); insert into public.eakan values(1,1,'2013-05-21'); insert into public.eakan values(2,1,'2013-05-21'); insert into public.eakan values(3,1,'2013-05-21'); ```I also created another table using the records of which I have to delete records in the earlier one.``` create table eakan\_del (sec\_id int, nameid int, date date); insert into public.eakan\_del values(1,1,'2013-05-21'); commit; ```I was naive initially and did something like this: First try:``` DELETE from eakan WHERE eakan.sec\_id IN (select eakan\_del.sec\_id from eakan\_del where eakan\_del.sec\_id=eakan.sec\_id and eakan\_del.date=eakan.date and eakan\_del.nameid=eakan.nameid) and eakan.date IN (select eakan\_del.date from eakan\_del where eakan\_del.sec\_id=eakan.sec\_id and eakan\_del.date=eakan.date and eakan\_del.nameid=eakan.nameid) and eakan.nameid in (select eakan\_del.nameid from eakan\_del where eakan\_del.sec\_id=eakan.sec\_id and eakan\_del.date=eakan.date and eakan\_del.nameid=eakan.nameid); Then I realized there should be another way and used some documentation of Vertica and also checked out Vertica Forums if something was available. ...