Data Types

HyperDB stores a fixed set of value types. Every value you write is normalized against its validator before it reaches the storage driver, which guarantees that what comes back out matches your schema.

Supported values

Validator	TypeScript type	Notes
v.string()	string
v.number()	number	Finite only — NaN/Infinity are rejected
v.bigint()	bigint
v.boolean()	boolean
v.null()	null
v.literal(x)	the literal	x is a string, number, bigint, boolean, or null
v.array(item)	T[]	Items cannot be undefined
v.object(fields)	{ ... }	Field map; optional fields may be omitted
v.record(key, value)	Record<K, V>	Keys are non-empty ASCII strings not starting with $
v.union(...)	a union	First matching variant wins
v.optional(inner)	T | undefined	Only meaningful for object fields
v.arrayBuffer()	ArrayBuffer	Typed arrays / data views are accepted and copied to an ArrayBuffer
v.any()	any	Validates structurally (see below)
v.pass<T>()	T	Accepts any value, no normalization

Composite helpers

• v.partial(objectValidator) — every field becomes optional.
• v.required(objectValidator, keys) — make listed optional fields required.
• v.lazy(() => validator) — defer resolution, useful for recursion.

Binary data

v.arrayBuffer() accepts an ArrayBuffer directly, and also accepts any typed array or DataView — these are copied into a fresh ArrayBuffer during normalization. Storage drivers encode binary data appropriately:

• The SQLite drivers encode bigint, ArrayBuffer, and typed-array/data-view values around JSON storage.
• The IndexedDB driver uses the same storage encoding and sort-key ordering as SQLite.
• The in-memory driver stores normalized JS values directly.

Indexable values

Not every value can appear in an index. Indexable value types are:

• string, finite number, bigint, boolean, null
• ArrayBuffer and typed-array / DataView values
• v.literal(...) of an indexable primitive
• v.union(...) where every variant is indexable
• v.optional(...) of an indexable value

If you try to build an index on a non-indexable column (an array, object, record, or any), defineTable throws. See Indexes.

The v.any() validator

v.any() accepts arbitrary JSON-like structures but still enforces HyperDB’s storage rules: numbers must be finite, object keys cannot be empty or start with $, and undefined is rejected inside arrays. Use it sparingly — you lose the type information and the index-ability that explicit validators give you.

Working with undefined

undefined is not a storable value. The rules:

• An optional object field may be omitted. Writing { note: undefined } is normalized to the field being absent — it round-trips as missing, not as undefined.
• undefined is not allowed inside an array ([1, undefined] is rejected).
• undefined is not allowed as a record value.

If you need to represent “explicitly empty”, model it with v.null() instead of relying on undefined.

Dates, times, and other rich types

There is no dedicated date type. Store timestamps as string (ISO-8601 sorts lexicographically, which works well with B-tree indexes) or as a number / bigint of epoch milliseconds. Reconstruct Date objects in your application code as needed.