MySQL : version differences notes (draft)

Relevant features added in Mysql 4.0

  • FULLTEXT search
  • INNODB tables (and on [delete|update features]
  • UNION statement
  • TRUNCATE TABLE statement
  • multiple table delete and update
Relevant features added in Mysql 4.1

  • Subquery (nested query) supported
  • “CREATE table LIKE table 2” syntax supported
  • added storages:
    – EXAMPLE (for developers)
    – NBCLUSTER (table partitioned over many computers)
    – CSV (comma separated values storage)
    – BLACKHOLE (it doesn’t store data)
  • added command “HELP”
  • API improved (multiple statement in a single call)
  • “INSERT … ON DUPLICATE KEY UPDATE” syntax added
  • GROUP_CONCAT() added
Relevant features added in Mysql 5.0

  • BIT data type
  • Math precision improved
  • SQLSTATE error message
  • TRIGGERS (limited support)
  • VARCHAR max length increased to 2^16 byte (64 Kb)
  • “greedy” optimizer, “merge index” to improve join performance
  • Improvement of “NOT IN”
  • VARCHAR more efficient
  • INNODB less disk space usage (-20%)
  • Added storages ARCHIVE and FEDERATED
Relevant features added in Mysql 5.1

  • Partitioning (tables in different locations)
  • plugin API to load/unload components at runtime
  • event scheduler (like cronotab)
  • customizable MySQL logs (to file or tables)
  • XML and XPath functions
Relevant features added in Mysql 6.0
  • UTF8 (4 bytes), UTF16 and UTF32
  • BACKUP_DATABASE and RESTORE statements (to backup)
  • performance optimization for subqueries and joins
  • transactional locks
  • LOAD_XML statement