Assessing what you have taken on.
WHAT TO ESTABLISH FIRST
Where it is How large What uses it Whether it is backed up
WHAT TO CHECK IMMEDIATELY
Whether a backup exists and has ever been restored Whether it is reachable from the internet What privileges the application account holds
WHY THOSE THREE
They are the ones that cause catastrophe.
WHAT TO INVENTORY
Tables and their sizes Engines in use Character sets and collations Indexes, and tables lacking them Foreign keys, and relationships without them
WHAT TO LOOK FOR
Tables with no primary key Money stored as floating point Dates stored as text Very wide tables Tables growing without limit
WHAT TO MEASURE
Slow queries Buffer pool hit rate Connection use
WHAT TO ASK
What changed most recently What has broken before Who else has access
WHAT TO FIX FIRST
Backups, then exposure, then privileges.
WHY IN THAT ORDER
They are the ones where the downside is unbounded.
WHAT TO PLAN NEXT
Indexing, and anything unbounded in growth.
WHAT TO DOCUMENT AS YOU GO
Everything you discover.
