v0.19.0-beta3

Bugfixing

• Fix checksum on indexes src-d/go-mysql-server#612
• SHOW WARNINGS doesn't clean warnings from one query to another src-d/go-mysql-server#600
• REGEXP invalid patterns doesn't break now src-d/go-mysql-server#606
• Improved function parameter errors src-d/go-mysql-server#591

New features

• cli: add --log-level option
• Adds a new optional feature behind EXPERIMENTAL_IN_MEMORY_JOIN environment variable to activate in-memory inner joins, which are faster but less memory efficient.