file-based NoSql database?
you can use unqlite + php-ext-unqlite
UnQLite is a in-process software library which implements a self-contained, serverless, zero-configuration, transactional NoSQL database engine. UnQLite is a document store database similar to MongoDB, Redis, CouchDB etc. as well a standard Key/Value store similar to BerkeleyDB, LevelDB, etc.
A complete database with multiple collections, is contained in a single disk file. The database file format is cross-platform, you can freely copy a database between 32-bit and 64-bit systems or between big-endian and little-endian architectures.
or use MongoLite
Schemaless database on top of SqLite
or use SDB
There are many key-value open-source databases that can be linked directly into your application. Here are a few:
- BerkeleyDB (now Oracle embedded database)
- Tokyo cabinet (hash table based)
- hamsterdb (disclaimer: i'm the author)
I'm not sure if BDB or TC offer PHP bindings. hamsterdb does not (yet).