{"repo":"doriantaylor/rb-rdf-lmdb","free":true,"listed":false,"github":"https://github.com/doriantaylor/rb-rdf-lmdb","clone":"git clone https://github.com/doriantaylor/rb-rdf-lmdb.git","description":"Symas (OpenLDAP) LMDB back-end for RDF::Repository","language":"Ruby","stars":17,"topics":["rdf","lmdb","database"],"license":"Apache-2.0","category":"databases-storage","readme_excerpt":"RDF::LMDB - Lightweight, persistent, transactional RDF store This library implements RDF::Repository using the Symas Lightning MDB key-value database. It is intended to be a basic, durable, locally-attached quad store, that avails itself of the properties of LMDB. RDF::LMDB is also intended to provide a reference implementation of an architecture for storing RDF in any key-value database, such that this adapter could be ported, or indeed the data imported , to other back-ends (e.g. Berkeley DB, LevelDB, Kyoto Cabinet…) without having to significantly change the design. The only real requirement for the back-end is some kind of cursor functionality, and the handling of multi-valued keys. Architecture The system uses binary SHA-256 digests of N-Triples representations of terms and statements. Terms are normalized first before being hashed. The hashes themselves are stored in their binary representation. Triples The main content of the store is keyed on the hash of a normalized N-Triples statement (including the terminating . ). Its values are the concatenated hashes of the individual terms: sha256(s p o \" .\") = sha256(s) sha256(p) sha256(o) GSPO There are four indices that resolve terms to statements, graph , subject , predicate , object , respectively: sha256(term) = sha256(s p o \" .\") Node Resolution Finally, there is an index that maps the digests of the terms back to their normalized N-Triples representations: sha256(term) = term API Documentation Generated and deposited in","default_branch":null,"files":null,"tree":[],"storefront":"/r/doriantaylor","claimed":false,"request_supported":{"post":"https://gitbuyer.com/r/doriantaylor/rb-rdf-lmdb/request-supported","requests":0},"note":"indexed from public GitHub; nothing is for sale on this page. Clone it from GitHub. Paid listings live at /search."}