OceanBase MySQL mode uses different collations for information_schema tables, causing "Illegal mix of collations" when joining COLUMNS with KEY_COLUMN_USAGE. Explicit COLLATE utf8mb4_general_ci resolves this. Closes #337
OceanBase MySQL mode uses different collations for information_schema tables, causing "Illegal mix of collations" when joining COLUMNS with KEY_COLUMN_USAGE. Explicit COLLATE utf8mb4_general_ci resolves this. Closes #337