Error
Error Code:
5179
SAP S/4HANA Error 5179: N-Gram Size Mismatch
Description
This error indicates a discrepancy between the expected and actual size of an n-gram used in text processing. It typically occurs when a system component, such as a search index or language detection service, attempts to process text data configured with an incompatible n-gram size.
Error Message
ERR_TEXT_COMMON_LID_INVALID_NGRAM_SIZE
Known Causes
4 known causesIncorrect Configuration
A text analysis or language detection service within SAP S/4HANA is configured to expect a specific n-gram size that does not match the size of the n-grams being processed or supplied.
Data Inconsistency
Textual data, often used for search or analytics, was indexed or prepared with an n-gram size that is inconsistent with the current system's requirements, leading to a mismatch during processing.
Custom Extension Conflict
A custom development or third-party extension is generating or consuming n-grams with a size that conflicts with the standard SAP S/4HANA configurations or integrated components.
System Update Mismatch
An incomplete or partial system update has led to different components operating with conflicting n-gram size expectations, causing processing failures.
Solutions
3 solutions available1. Rebuild Full-Text Search Index for Affected Table medium
This solution involves rebuilding the full-text search index for the specific table causing the N-Gram size mismatch.
1
Identify the table experiencing the N-Gram size mismatch. This often requires analyzing the SAP application logs or traces that provide more context around error 5179.
2
Connect to your SAP HANA database using a SQL client (e.g., SAP HANA Studio, hdbsql).
3
Execute the `ALTER FULLTEXT INDEX` statement to rebuild the index. Replace `YOUR_SCHEMA_NAME` and `YOUR_TABLE_NAME` with the actual schema and table names. The `REBUILD` option forces a re-indexing process, which will re-evaluate and align N-Gram sizes.
ALTER FULLTEXT INDEX ON "YOUR_SCHEMA_NAME"."YOUR_TABLE_NAME" REBUILD;4
Monitor the rebuild process. Large tables may take a considerable amount of time. Check the SAP HANA trace files or system views for progress and potential errors during the rebuild.
5
After the rebuild is complete, test the functionality that triggered the error to confirm it's resolved.
2. Verify and Correct N-Gram Settings in Table Definition advanced
This solution focuses on directly inspecting and rectifying the N-Gram configuration within the table's full-text index definition.
1
Identify the specific table and column(s) involved in the full-text search that's causing the error. This information should be available in the SAP application logs or debugging traces.
2
Query the SAP HANA system views to retrieve the current full-text index configuration for the identified table. Pay close attention to the `NVALUE` (N-Gram size) and `NGRAMTYPE` settings for the relevant text columns.
SELECT * FROM SYS.FULLTEXT_INDEXES WHERE TABLE_NAME = 'YOUR_TABLE_NAME' AND SCHEMA_NAME = 'YOUR_SCHEMA_NAME';3
Compare the retrieved N-Gram settings with the expected or default values for the SAP S/4HANA version and language being used. Consult SAP Notes or documentation for recommended N-Gram configurations.
4
If a mismatch is found, use the `ALTER FULLTEXT INDEX` statement to correct the N-Gram settings. For example, to set the N-Gram size to 2 for a specific column:
ALTER FULLTEXT INDEX ON "YOUR_SCHEMA_NAME"."YOUR_TABLE_NAME" MODIFY TEXT COLUMN "YOUR_TEXT_COLUMN_NAME" NVALUE 2;5
After applying the changes, it's highly recommended to rebuild the index to ensure the new settings are fully effective.
ALTER FULLTEXT INDEX ON "YOUR_SCHEMA_NAME"."YOUR_TABLE_NAME" REBUILD;6
Test the application functionality to ensure the error is resolved.
3. Apply SAP Notes for Known Issues easy
This is a quick-fix approach that addresses the error if it's a known bug resolved by an SAP Note.
1
Search the SAP Support Portal (SAP ONE Support Launchpad) for SAP Notes related to 'Error 5179', 'ERR_TEXT_COMMON_LID_INVALID_NGRAM_SIZE', and 'SAP S/4HANA Full-Text Search'.
2
Review the identified SAP Notes to determine if the error you are experiencing is covered by a specific correction or enhancement.
3
If a relevant SAP Note is found, follow the instructions provided in the Note to implement the necessary corrections. This typically involves applying Support Packages or manually implementing code corrections.
4
After applying the SAP Note, restart the relevant SAP S/4HANA application components or the entire system if recommended by the Note.
5
Test the functionality that previously caused the error to verify the resolution.