# Memory

> The in-process adapter, for tests and throwaway work.

```ts
import { MemoryBlockStore } from "@minnowdb/core/storage";
import { MinnowDatabase } from "@minnowdb/core";

const db = new MinnowDatabase(new MemoryBlockStore());
```

No options, nothing to open, nothing to clean up. It implements the same `BlockStore` contract as
the IndexedDB adapter, including atomic commits, snapshot reads, leases, and conflict detection —
so a test against it exercises the same engine paths an application uses, not a simplified
stand-in.

## What it is for

**Tests.** A fresh database per test with no cleanup and no shared state between them.

```ts
function freshDatabase(): MinnowDatabase {
  return new MinnowDatabase(new MemoryBlockStore());
}
```

**Ephemeral analysis.** A file a user dropped in, queried, and will never look at again does not
need to touch their disk or their quota.

**Building data to publish.** A [snapshot](/docs/storage/snapshots.md) exported from a memory store
is how a prepared database becomes a file — a build script loads rows in memory and writes one
portable artifact.

## What it costs

Everything lives in JavaScript memory: block payloads stay compressed, but they stay resident.
Budget roughly what the same data would occupy in IndexedDB, plus the catalog.

Nothing survives a reload, and nothing is shared between tabs — two tabs each get their own
database. Where the IndexedDB adapter's cross-tab behaviour needs testing, that has to be a
browser test against the real store.

---

Minnow 0.1.0 · this page on the site: /docs/storage/memory/