references, 2493 REFERENCES privilege, 1192 referential integrity, 2998, 6181 REFERENTIAL_CONSTRAINTS INFORMATION_SCHEMA table, 4812 Refresh thread command, 1846 ref_or_null, 1679 ref_or_null join type optimizer, 1767 REGEXP, 2191 REGEXP operator, 2190 REGEXP_INSTR(), 2191 REGEXP_LIKE(), 2193 REGEXP_REPLACE(), 2194 regexp_stack_limit system variable, 868 REGEXP_SUBSTR(), 2195 regexp_time_limit system variable, 868 Register Slave thread command, 1847 Registering slave on master thread state, 1855 regular account account categories, 1233 regular expression syntax, 2190 regular expressions in JSON schemas, 2384 new features, 28 regular session session categories, 1234 rehash command mysql, 437 rejects option ndb_import, 4331 relational, 6181 relational databases defined, 5 relative option mysqladmin, 458 relay log (replication), 3599 relay-log-purge option mysqld, 3506 relay-log-space-limit option mysqld, 3507 relay_log system variable, 3519 relay_log_basename system variable, 3520 relay_log_index system variable, 3520 relay_log_info_file deprecated features, 41 relay_log_info_file system variable, 3521 relay_log_info_repository system variable, 3521, 3599 relay_log_purge system variable, 3522 relay_log_recovery system variable, 3522 relay_log_space_limit system variable, 3523 

