A different relational database.
WHAT DISTINGUISHES IT
Strict standards compliance Rich data types, including structured documents and arrays Powerful indexing options Strong transactional behaviour, including for schema changes
WHY THAT LAST POINT MATTERS
Schema changes can be rolled back within a transaction, which MySQL cannot do.
WHAT DIFFERS IN ADMINISTRATION
Configuration file locations and names The client and its commands Backup tooling User and permission model
WHAT THE INTERACTIVE CLIENT IS
A terminal client with its own commands, prefixed by a backslash.
WHAT THE ESSENTIAL ONES ARE
List databases Connect to one List tables Describe a table Quit
WHAT VACUUM DOES
Reclaims space from rows made obsolete by updates and deletes.
WHY IT IS NECESSARY
Updates create new row versions rather than overwriting.
WHAT HAPPENS WITHOUT IT
Tables bloat, and performance degrades.
WHAT AUTOVACUUM PROVIDES
Doing it automatically.
WHAT TO MONITOR
Whether it is keeping up on busy tables.
WHAT ELSE TO WATCH
Transaction identifier age, which requires attention on very busy systems.
WHAT BACKUP TOOLS EXIST
A dump tool, and a physical backup tool supporting point-in-time recovery.
WHEN TO CHOOSE IT
When you need its data types, strictness, or advanced indexing.
