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