How to define the columns to be analyzed - 6.5

Talend Open Studio for Data Quality User Guide

Talend Open Studio for Data Quality
Data Quality and Preparation
Talend Studio

The first step in analyzing the content of one or multiple columns is to define the column(s) to be analyzed. The analysis results provides statistics about the values within each column.

Prerequisite(s): At least one connection to a delimited file is set in the Profiling perspective of the studio. For further information, see Connecting to a file.

Defining the analysis

  1. In the DQ Repository tree view, expand the Data Profiling folder.

  2. Right-click the Analysis folder and select New Analysis.

    The [Create New Analysis] wizard opens.

  3. In the filter field, start typing basic column analysis, select Basic Column Analysis and click Next.

  4. In the Name field, enter a name for the current column analysis.


    Avoid using special characters in the item names including:

    "~", "!", "`", "#", "^", "&", "*", "\\", "/", "?", ":", ";", "\"", ".", "(", ")", "'", "¥", "'", """, "«", "»", "<", ">".

    These characters are all replaced with "_" in the file system and you may end up creating duplicate items.

  5. Set column analysis metadata (purpose, description and author name) in the corresponding fields and click Next to proceed to the next step.

Selecting the file columns and setting sample data

  1. Expand FileDelimited connections and in the desired file, browse to the columns you want to analyze.

    In this example, you want to analyze the id, first_name and age columns from the selected connection.

  2. Select the columns and then click Finish to close the wizard.

    A file for the newly created column analysis is listed under the Analysis node in the DQ Repository tree view, and the analysis editor opens with the analysis metadata.

  3. In the Data preview view, click Refresh Data.

    The data in the selected columns is displayed in the table.

    You can change your data source and your selected columns by using the New Connection and Select Columns buttons respectively.

  4. In the Limit field, set the number for the data records you want to display in the table and use as sample data.

    For example, 50 records.

  5. Select n first rows to list the first 50records from the selected columns.

  6. In the Analyzed Columns view, use the arrows in the top right corner to open different pages in the view if you analyze large number of columns.

    You can also drag the columns to be analyzed directly from the DQ Repository tree view to the Analyzed Columns list in the .

  7. Use the delete, move up or move down buttons to manage the analyzed columns.

  8. If required, right-click any of the listed columns in the Analyzed Columns view and select Show in DQ Repository view to locate it in the database connection in the DQ Repository tree view.

When you select to analyze Date columns and run the analysis with the Java engine, the date information is stored in the studio as regular date/time of format YYYY-MM-DD HH:mm:ss.SSS for date/timestamp and of format HH:mm:ss.SSS for time. The date and time formats are slightly different when you run the analysis with the SQL engine.