Bug #87925 Optionally don't make a query fail with USE INDEX (non_existing_index)

• Submitted: 30 Sep 2017 17:27
• Reporter: Federico Razzoli (OCA)
• Status: Open
• Category: MySQL Server: DDL
• Severity: S4 (Feature request)
• OS: Any
• CPU Architecture: Any

[30 Sep 2017 17:27] Federico Razzoli

Description:
A query like this:

SELECT ... FROM t USE/FORCE/IGNORE INDEX (index_name) ...

will fail with an error if specified index does not exist. This seems to me the best behaviour in test environment, but dangerous in production.

Think about this case: my db is used in production, at some point I remove an index which seems useless, and suddenly some queries fail.

So what I'm asking (unless you have better ideas to solve this problem) is having a new system variable which determines if queries like this should fail with an error, or just produce a warning.

How to repeat:
SELECT * FROM information_schema.TABLES USE INDEX (not_existing_index);