Search results
Results from the WOW.Com Content Network
In computer science, an inverted index (also referred to as a postings list, postings file, or inverted file) is a database index storing a mapping from content, such as words or numbers, to its locations in a table, or in a document or a set of documents (named in contrast to a forward index, which maps from documents to content). [1]
Elasticsearch is a search engine based on Apache Lucene. It provides a distributed, multitenant -capable full-text search engine with an HTTP web interface and schema-free JSON documents. Official clients are available in Java , [ 2 ] .NET [ 3 ] ( C# ), PHP , [ 4 ] Python , [ 5 ] Ruby [ 6 ] and many other languages. [ 7 ]
Concept of a mapping table. An associative (or junction) table maps two or more tables together by referencing the primary keys (PK) of each data table. In effect, it contains a number of foreign keys (FK), each in a many-to-one relationship from the junction table to the individual data tables. The PK of the associative table is typically ...
In the future, tools based on semantic web languages such as RDF, the Web Ontology Language (OWL) and standardized metadata registry will make data mapping a more automatic process. This process will be accelerated if each application performed metadata publishing. Full automated data mapping is a very difficult problem (see semantic translation).
This type of "translating" from one format to another is often called "metadata mapping" or "field mapping," and is related to "data mapping", and "semantic mapping". Crosswalks also have several technical capabilities. They help databases using different metadata schemes to share information. They help metadata harvesters create union catalogs.
Systems like Elasticsearch use inverted indexes for efficient text-based searches, but they can still require full scans for non-indexed fields. This behavior reflects the design focus of many NoSQL systems on scalability and efficient key-based operations rather than optimized querying for arbitrary fields.
Géoportail - government run public service mapping, covers the whole French territory; ViaMichelin - World maps, city maps, driving directions, Michelin-starred restaurants, hotel booking, traffic news and weather forecast with ViaMichelin. Germany "Geoportal.de", by the Federal Agency for Cartography and Geodesy (BKG). Hong Kong
This table shows the effect of each bit. At each stage, the relevant half of the range is highlighted in green; a low bit selects the lower range, a high bit selects the upper range. The column "mean value" shows the latitude, simply the mean value of the range.