apache

This section explains the Tajo DDL commands. Tajo has a built-in database named default. Create Database Statement Create Database is a statement used to create a database in Tajo. The syntax for…

The JSON functions are listed in the following table − S.No.Function & Description1json_extract_path_text(js on text, json_path text)Extracts JSON string from a JSON string based on json path specified.2json_array_get(json_array text, index…

Apache Tajo supports the following DateTime functions. S.No.Function & Description1add_days(date date or timestamp, int dayReturns date added by the given day value.2add_months(date date or timestamp, int month)Returns date added by…

The following table lists out the string functions in Tajo. S.No.Function & Description1concat(string1, ..., stringN)Concatenate the given strings.2length(string)Returns the length of the given string.3lower(string)Returns the lowercase format for the string.4upper(string)Returns…

Math functions operate on mathematical formulae. The following table describes the list of functions in detail. S.No.Function & Description1abs(x)Returns the absolute value of x.2cbrt(x)Returns the cube root of x.3ceil(x)Returns x…

The following operators are used in Tajo to perform desired operations. S.No.Operator & Description1Arithmetic operatorsPresto supports arithmetic operators such as +, −, *, /, %.2Relational operators<, >, <=, >=, =,…

To execute a query in a Tajo shell, open your terminal and move to the Tajo installed directory and then type the following command − $ bin/tsql You will now…

In this chapter, we will understand the Tajo Shell commands in detail. To execute the Tajo shell commands, you need to start the Tajo server and the Tajo shell using…

Tajo’s configuration is based on Hadoop’s configuration system. This chapter explains Tajo configuration settings in detail. Basic Settings Tajo uses the following two config files − catalog-site.xml − configuration for…

To install Apache Tajo, you must have the following software on your system − Hadoop version 2.3 or greaterJava version 1.7 or higherLinux or Mac OS Let us now continue…