The Vertica query history tables are used for various applications, for example, identify long running queries, identify skewed node, identify the load on Vertica cluster. Vertica supports management console to identify the cluster status. The Vertica database also provides tables that stores information about the requests that are made to server. Information includes query history, time, username, userid, etc. In this article, we will check Vertica query history tables available in the Vertica analytics database. Before jumping into query history tables, let us check why query historical data is required?…

In a data warehouse environment, being a heterogeneous source, you may get lot of different kinds of data in terms of pipeline, flat files extracted from these data sources. Received data may be corrupted during transfer, or may have unwanted characters. You can use Vertica built in functions and regular expression to clean such corrupted and unwanted data. HP Vertica Support many built in functions, you can use those built in functions to extract numbers, specific string, or alphanumeric values from the string. In this article, we will discuss one…

Variable substitution is nothing but passing value to a variable referred in Vertical SQL queries. Let me explain this using an example. Imagine you have written a general SQL script to generate monthly aggregated data for a particular report, you have to provide a current month values to a filter variable referred in SQL script. Another instance could be executing Vertica SQL queries from Linux shell script and passing shell variable value to a variable referred in SQL script. You can accomplish this task using Vertica vsql variable substitution method.…