ETL with talend

POOJA B. MISHRA

What is ETL?Extract is the process of reading data from a database

Transform is the process of converting the extracted data from its previous form into the form it needs to be in so that it can be placed into another database. Transformation occurs by using rules or lookup tables or by combining the data with other data

Load is the process of writing the data into the target database

Process flow

Terms closely related and managed by ETL processes data migrationdata management data cleansingdata synchronization data consolidation.

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Different ETL tools

•Informatica PowerCenter•Oracle ETL•Ab Initio•Pentaho Data Integration -Kettle Project (open source ETL)•SAS ETL studio•Cognos Decisionstream•Business Objects Data Integrator (BODI)•Microsoft SQL Server Integration Services (SSIS) •Talend

Prerequisites Talend Open Studio for Data Integration

◦ http://www.talend.com/download VirtualBox

◦ https://www.virtualbox.org/wiki/Downloads Hortonworks Sandbox VM

◦ http://hortonworks.com/products/hortonworks-sandbox/#install

How to set up – Step 1

Step 2

Step 3

Step 5

Talend InterfaceWorkspace

Repository tree

Component configuration

Palette

WorkspaceRepository tree

Palette

Repository tree

Workspace

Palette

Component configuration

Supported data input and output formats?

• SQL

•MySQL

• PostgreSQL

• Sybase

• Teradata

•MSSQL

•Netezza

•Greenplum

•Access

•DB2

Hive

Pig

Hbase

Sqoop

MongoDB

Riak

Many more

What kinds of datasets can be loaded?

Talend Studio offers nearly comprehensive connectivity to:

Packaged applications (ERP, CRM, etc.), databases, mainframes, files, Web Services, and so on to address the growing disparity of sources.

Data warehouses, data marts, OLAP applications - for analysis, reporting, dashboarding, scorecarding, and so on.

Built-in advanced components for ETL, including string manipulations, Slowly Changing Dimensions, automatic lookup handling, bulk loads support etc.

Tutorial overview

We will do following tasks in this assignment:

1. Load data from DB on your local machine to HDFS 2. Write hive query to do analysis

3. Result of above hive query is then pushed to HBase output component

Step 1 Use row generator to simulate the rows in db and created a table with 3 columns, ID, name and level.

Step 2• Drag and drop the hdfsoutput component to the

surface and connect the major output of the row generator to the hdfs.

• For hdfs component, double click on the HDFS component in design area and just specify the name node address, and the folder in your machine to hold the file

Step 3 After loading the data to HDFS, we can create

external hive table customers using following command by logging in hive shell and executing following command

CREATE EXTERNAL TABLE customers(id INT, name STRING, level STRING) ROW FORMAT DELIMITED FIELDS TERMINATED BY STORED AS TEXTFILE LOCATION '/usr/talend';

Step 4 Create one flow to read the data in hive. pick up the version ,and the thrift server ip/port, then write a hive query as shown in below screen

Step 5 Click the edit schema button and just add one column with type as object then we will parse the result and map to our schema.

Click the advanced tab, to enable the parse query results, using the column we just created as object type.

Drag the parserecordset component to the surface and conenct the mainout of hiverow to it, click edit schema to do the necessary mapping and then match the values as shown belowust created as object type

Results

Step 6◦ Click to run this job, from

the console it tell you whether it has connected to the hive server successfully

◦ Go to the hive server and it will show you that it has received one query and will execute it

◦ you can see the results from the run talend console

Step 7 Drag one component called hbaseoutput from right pallette, and config the zookeeper info

Step 8 Run the job will get this as final output

You can login into hbase shell and check if data is insterted to the hbase and the table was created by talend also!

Thank You!!