Generating an analysis on the join results to analyze duplicates - 7.1

Talend Real-time Big Data Platform Studio User Guide

author
Talend Documentation Team
EnrichVersion
7.1
EnrichProdName
Talend Real-Time Big Data Platform
task
Design and Development
EnrichPlatform
Talend Studio

In some cases, when you analyze database tables using an SQL business rule that has a join clause, the join results show that there are more rows in the joint than in the analyzed table.

This is because the columns in the analyzed table has some duplicate records, for an example see Creating a table analysis with an SQL business rule with a join condition.

You can generate a ready-to-use analysis to analyze these duplicate records. The results of this analysis help you to better understand why there are more records in the join results than in the table.

Before you begin

A table analysis with an SQL business rule, that has a join condition, is defined and executed in the Profiling perspective of the studio. The join results must show that there are duplicates in the table. For further information, see Creating a table analysis with an SQL business rule with a join condition.

Procedure

  1. After creating and executing an analysis on a table that has duplicate records as outlined in Creating a table analysis with an SQL business rule with a join condition, click the Analysis Results tab at the bottom of the analysis editor.
  2. Right-click the join results in the second table and select Analyze duplicates.

    The Column Selection dialog box opens with the analyzed tables selected by default.

  3. Modify the selection in the dialog box if needed and then click OK.
    Two column analyses are generated and listed under the Analyses folder in the DQ Repository tree view and are open in the analysis editor.
  4. Save the analysis and press F6 to execute it.
    The analysis results show two bars, one representing the row count of the data records in the analyzed column and the other representing the duplicate count.
  5. Click Analysis Results at the bottom of the analysis editor to access the detail result view.
  6. Right-click the row count or duplicate count results in the table, or right-click the result bar in the chart itself and select:

    Option

    To...

    View rows

    open a view on a list of all data rows or duplicate rows in the analyzed column.

    View values

    open a view on a list of the duplicate data values of the analyzed column.

    Identify duplicates

    generate a ready-to-use Job that identifies and separates unique and duplicate records in the selected column for subsequent processing. This Job outputs all the duplicates in a reject .csv file by default, and writes the unique values in another separate file. For further information, see Generating a Job to Identify duplicate values in an analyzed column.