Previewing Data Before Import

Previewing Data Before Import

Before committing to a full import, MatchLogic allows you to preview a sample of your data to make sure everything looks correct. This preview step helps you catch formatting issues, incorrect delimiters, encoding problems, or unexpected data early, before investing time in a full import.

Accessing the Preview

The data preview is available during the import workflow, after your file has been uploaded or your database/cloud connection has been established. Look for the Preview tab or section on the column mapping screen. The preview loads a sample of rows from your source data using the columns you have configured.

What the Preview Shows

The preview displays a table with:

• Column headers — Using the "New Name" values from your column mapping configuration. This lets you verify that renamed columns look right.
• Sample rows — A subset of records from the beginning of your dataset. The number of rows shown varies but is typically enough to verify the data structure.
• Data values — The actual content of each cell, so you can confirm that values are being parsed correctly.

What to Look For

When reviewing the preview, check for the following common issues:

• Misaligned columns — If data appears in the wrong columns, the delimiter or file format may not have been detected correctly. For CSV files, this can happen when the file uses a semicolon or tab delimiter instead of a comma.
• Garbled characters — If you see unexpected characters (e.g., é instead of e), the file encoding may not match what MatchLogic expects. This is more common with older files or files created on different operating systems.
• Missing header row — If the first row of data appears to contain actual records rather than column names, your file may not have a header row. In this case, the auto-detected column names will be generic (e.g., Column1, Column2).
• Empty or mostly-empty columns — If a column appears blank in most preview rows, consider whether it is worth including in the import. You can uncheck it in the column mapping step.
• Unexpected data types — Verify that numeric fields contain numbers, date fields contain dates, and so on. While MatchLogic treats all data as text during import, spotting anomalies now helps with downstream profiling and matching.

Exceptions Tab

In addition to the data preview, an Exceptions tab may be available. This tab lists any issues detected during the initial file scan, such as:

• Empty tables or sheets in an Excel file
• Rows with an inconsistent number of columns (more or fewer than the header)
• Encoding detection warnings

Review any exceptions before proceeding. They may indicate data quality issues that should be addressed at the source or handled during the cleansing stage.

Proceeding After Preview

If the preview looks correct, return to the column mapping configuration and click Import to start the full import. If you spot issues, address them (adjust column mapping, fix the source file, or change connection settings) before importing.