schema

type Fkey struct {
	Table   string
	Columns []string
	IIndex  int
	Mode    byte
}

type Index struct {
	Ixspec  ixkey.Spec
	Columns []string
	// BestKey is the key used to make indexes ('i' and 'u') unique.
	// A key used as BestKey must not be dropped.
	// BestKey must be persisted (unlike Primary and ConstainsKey)
	// because it affects the btrees and modifying the schema could change it.
	BestKey []string
	// FkToHere is other foreign keys that reference this index
	FkToHere []Fkey // filled in by meta
	Fk       Fkey
	// Mode is 'k' for key, 'i' for index, 'u' for unique index
	Mode byte
	// Primary is true for keys ('k') that do not contain another key.
	// Only primary keys need duplicate checking.
	Primary bool
	// ContainsKey is true for indexes ('i' and 'u') that contain a key.
	// Unique indexes ('u') that contain a key do not need duplicate checking.
	ContainsKey bool
}

type Schema struct {
	Table string
	// Columns are the physical fields in the records, in order
	Columns []string
	// Derived are the rules (capitalized) and _lower!
	Derived []string
	Indexes []Index
}