PouchDB is a free and open-source JavaScript DBMS inspired by Apache CouchDB (document-oriented NoSQL DBMS) that is designed to run inside a web browser. It was designed with the intention of serving web developers and to run smoothly within a browser. Applications utilize a system where, while offline, data is stored locally, then, when back online, the data is synchronized with Apache CouchDB and between clients. Thus, data is synchronized regardless of login context.[01]
- Website
- https://pouchdb.com[01]
- Source Code
- https://github.com/apache/pouchdb[02]
- Tech Docs
- https://pouchdb.com/guides[03]
- Country of Origin
- US
- Start Year
- 2010 [15]
- Project Type
- Open Source
- Written in
- JavaScript
- Derived From
- CouchDB
- Inspired By
- CouchDB
- License
- Apache v2
PouchDB is a free and open-source JavaScript DBMS inspired by Apache CouchDB (document-oriented NoSQL DBMS) that is designed to run inside a web browser. It was designed with the intention of serving web developers and to run smoothly within a browser. Applications utilize a system where, while offline, data is stored locally, then, when back online, the data is synchronized with Apache CouchDB and between clients. Thus, data is synchronized regardless of login context.[01]
Checkpoints[05]
PouchDB allows users to enable or disable replication checkpoints (which would be modified based on system performance goals and/or usage), which are used for synchronization across the local and remote servers.
Compression[06]
PouchDB doesn't currently support compression by default, however there is a plugin (Transform Pouch) that allows for compression of data.
Concurrency Control
PouchDB's concurrency control policy is multi-version concurrency control, allowing consistency of reads.
Data Model[07][08]
PouchDB uses an unstructured document data model, where documents are JSON serializable. It also supports attachments, which store binary data.
Indexes[10]
Starting with version 2.2.0, PouchDB supports secondary indexes using B-trees. The default index is build on the _id field.
Query Execution
PouchDB can use map/reduce or create MangoQueries (used to build secondary indexes). Users can create an empty query to speed up the query. By dividing into map and reduce, parallelism can speed up the process.
Query Interface[11]
PouchDB utilizes a custom API for its query interface. As it is designed for web browsers, this API supports callbacks, promises, and async functions.
Storage Organization[12][13]
When offline, data is stored locally using WebSQL (deprecated) or IndexedDB, depending on the browser. For IndexedDB usage, the method of storage organization is ISAM. When online, data synchs with CouchDB (and other servers). CouchDB storage uses copy-on-write to update database files. (TODO: select two options).
Views[07][14]
PouchDB supports creating materialized views of the results of a query. It's very similar to CouchDB however PouchDB uses ASCII ordering to order view query keys. It also does not support the offset property that CouchDB does. Instead, a skip parameter is used instead of an actual offset.
RxDB
Citations
15 sources- PouchDB, the JavaScript Database that Syncs! pouchdb.com
- GitHub - apache/pouchdb: :kangaroo: - PouchDB is a pocket-sized database. · GitHub github.com
- Introduction to PouchDB pouchdb.com
- Apache CouchDB - Wikipedia wikipedia.org
- PouchDB 6.3.0 pouchdb.com
- GitHub - pouchdb-community/transform-pouch: PouchDB plugin for modifying documents before and after storage in the database. · GitHub github.com
- FAQ pouchdb.com
- https://pouchdb.com/guides/documents.html pouchdb.com
- https://db-engines.com/en/system/PouchDB;Tibero db-engines.com
- pouchdb/packages/node_modules/pouchdb-find at master · apache/pouchdb · GitHub github.com
- API Reference pouchdb.com
- http://blog.nparashuram.com/2011/03/indexeddb-store-in-your-browser.html nparashuram.com
- https://dbdb.io/db/couchdb dbdb.io
- Materialized views in PouchDB - Stack Overflow stackoverflow.com
- Initial skeleton. github.com