What Is the NORMALIZE Function in BigQuery?

The NORMALIZE Function in BigQuery helps eliminate discrepancies caused by variations in text encoding or accent marks. By unifying text data, the NORMALIZE Function supports cleaner comparisons, searches, and transformations, critical for analytics, reporting, and multilingual data management.

Why You Should Use the NORMALIZE Function in BigQuery

Using the NORMALIZE Function ensures that text data is consistent and comparable, regardless of how it was entered or sourced.

• Improves Data Accuracy: Prevents mismatches caused by inconsistent encoding or special characters.
• Simplifies Data Integration: Aligns text from multiple systems or languages.
• Enhances Search Operations: Ensures that queries return accurate results even with accented or alternate characters.
• Supports Multilingual Data: Handles inputs with global alphabets and diacritics seamlessly.

With normalized text, data analysts can ensure better consistency in joins, filters, and aggregations.

How the NORMALIZE Function Works in BigQuery

The NORMALIZE Function reformats text according to Unicode normalization forms, making visually identical strings structurally consistent.
Process Overview:

1. The function takes an input string and applies a specified normalization form.
2. It then outputs a standardized version of the string that’s uniform across systems.
3. Common normalization forms include NFC, NFD, NFKC, and NFKD.

This process ensures that equivalent characters—like accented letters, are treated as the same value for analysis and comparison.

NORMALIZE Function Syntax and Optional Parameters

The NORMALIZE Function can be customized to use different Unicode normalization forms.
Syntax:

NORMALIZE(value[, form])

• value: The string to normalize.
• form: (Optional) The normalization type. Available options are NFC, NFD, NFKC, and NFKD.

If no form is specified, BigQuery defaults to NFC. Each form handles text differently, such as combining or decomposing accented characters for consistent encoding.

Example of Using the NORMALIZE Function in BigQuery

Here’s an example showing how NORMALIZE standardizes text data:

SELECT NORMALIZE('e\u0301', 'NFC') AS normalized_text;

Result:

é

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In this case, the function converts the decomposed version of the accented “e” (e + ́) into its single combined form (é). This ensures that comparisons between visually identical but structurally different texts yield consistent results.

Best Practices for Using the NORMALIZE Function in BigQuery

Follow these best practices to use the NORMALIZE Function effectively in BigQuery:

• Identify Encoding Issues: Audit text fields from various sources before normalization.
• Choose the Right Form: Use NFC for general normalization and NFKC for broader compatibility.
• Integrate Early: Normalize data during ingestion or preprocessing to avoid mismatches later.
• Test Comparisons: Verify outputs after normalization to confirm consistency.
• Combine with CASEFOLD: Use NORMALIZE_AND_CASEFOLD when you also need case-insensitive comparison.

These guidelines help ensure cleaner, more accurate text processing in analytical workflows.

Standardize Your Data with OWOX Data Marts

OWOX Data Marts Cloud automates SQL transformations like NORMALIZE to ensure consistent, high-quality text data across analytics environments. It allows analysts to define standardized data logic, manage refreshes, and deliver clean, comparable datasets to Sheets or BI tools. With built-in governance and automation, OWOX helps teams maintain accuracy and trust across global, multilingual data pipelines.

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