Bug #83396 ngram_token_size per table and dynamic

• Submitted: 16 Oct 2016 10:30
• Modified: 3 Nov 2016 6:57
• Reporter: Daniël van Eeden (OCA)
• Status: Verified
• Category: MySQL Server: FULLTEXT search
• Severity: S4 (Feature request)
• Version: 5.7.15
• OS: Any
• CPU Architecture: Any
• Tags: CJK, dynamic, fulltext, NGRAM, online

[16 Oct 2016 10:30] Daniël van Eeden

Description:
Variable 'ngram_token_size' is a read only variable.

I would very much like to see a per-schema and per-table ngram_token_size. Maybe even per index.

Some possible examples:
- one mysql instance with multiple unrelated schema's (e.g. shared hosting, multiple small internal tools, etc). Here a per schema setting makes sense.
- Optimizing one big FTS index which could be smaller if the token size would be different. Here a per table or per index setting makes sense.

This is needed to combine slightly different usecases and/or requirements on one server.

How to repeat:
mysql-5.7.15 [test] > set global ngram_token_size=3;
ERROR 1238 (HY000): Variable 'ngram_token_size' is a read only variable

[3 Nov 2016 6:57] MySQL Verification Team

Hello Daniël,

Thank you for the feature request!

Thanks,
Umesh