query-ee1f964e8733776b3b8121527479b6bc

rq turtle/ttl

Automatic optimisation -- background overviewThe basic approach to query optimisation is to try to get the solution set to be as small as possible as soon as possible in the query execution, to make the work needed for subsequent joins as small as it can be. A subsidiary goal can be to maximise the possibility of pipelining and parallelisation. This is what Blazegraph's built-in query optimiser tries to achieve. For example, here is a query to return a list of U.S. Presidents and their spouses: US presidents and their spousesIt is all very well to be able to look up all the statements that can be related to a particular string, but more usually we would like to be able to ask questions relating to specific items and properties. Next, then, here is a query involving some actual Wikidata properties and items. The following is a query to return a list of married U.S. presidents and their spouses: Optimisation automatique -- aperçu d'arrière planL’approche de base pour l’optimisation de requête est d’essayer de réduire la taille de l’ensemble des solutions le plus petit possible le plus tôt possible lors de l’exécution de la requête. Ainsi le travail à faire pour les jointures suivantes est le plus petit possible. Un but annexe peut être de maximiser les possibilités d’ordonnancement et de parallélisation. C’est ce que l’optimiseur intégré de Blazegraph tente de réaliser. Par exemple : voici une requête pour retourner une liste des présidents des Etats-Unis et leurs épouses : Automatic optimisation -- background overview The basic approach to query optimisation is to try to get the solution set to be as small as possible as soon as possible in the query execution, to make the work needed for subsequent joins as small as it can be. A subsidiary goal can be to maximise the possibility of pipelining and parallelisation. This is what Blazegraph's built-in query optimiser tries to achieve. For example, here is a query to return a list of U.S. Presidents and their spouses: Automatische optimalisatie -- overzicht achtergrondenDe basisaanpak van queryoptimalisatie is om te proberen de oplossingsset zo snel mogelijk zo klein mogelijk te maken in de uitvoering van de query, om het werk dat nodig is voor volgende joins zo klein mogelijk te maken. Een volgend doel kan zijn om de mogelijkheid van leidingen en parallelisering te maximaliseren. Dit is wat de ingebouwde optimizer van Blazegraph probeert te bereiken. Hier is bijvoorbeeld een query om een lijst te geven van Amerikaanse presidenten en hun echtgenoten: TODO Automatic optimisation -- background overview The basic approach to query optimisation is to try to get the solution set to be as small as possible as soon as possible in the query execution, to make the work needed for subsequent joins as small as it can be. A subsidiary goal can be to maximise the possibility of pipelining and parallelisation. This is what Blazegraph's built-in query optimiser tries to achieve. For example, here is a query to return a list of U.S. Presidents and their spouses: Автоматична оптимізація -- попередній огляд The basic approach to query optimisation is to try to get the solution set to be as small as possible as soon as possible in the query execution, to make the work needed for subsequent joins as small as it can be. A subsidiary goal can be to maximise the possibility of pipelining and parallelisation. This is what Blazegraph's built-in query optimiser tries to achieve. For example, here is a query to return a list of U.S. Presidents and their spouses: 自动优化 - 背景概述 The basic approach to query optimisation is to try to get the solution set to be as small as possible as soon as possible in the query execution, to make the work needed for subsequent joins as small as it can be. A subsidiary goal can be to maximise the possibility of pipelining and parallelisation. This is what Blazegraph's built-in query optimiser tries to achieve. For example, here is a query to return a list of U.S. Presidents and their spouses:

Use at

PREFIX wikibase: <http://wikiba.se/ontology#>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX bd: <http://www.bigdata.com/rdf#>
SELECT ?pres ?presLabel ?spouse ?spouseLabel WHERE {
   ?pres wdt:P31 wd:Q5 .
   ?pres wdt:P39 wd:Q11696 .
   ?pres wdt:P26 ?spouse .
   SERVICE wikibase:label {
    bd:serviceParam wikibase:language "en" .
   }
 }

Query found at

graph TD classDef projected fill:lightgreen; classDef literal fill:orange; classDef iri fill:yellow; v1("?pres"):::projected v2("?spouse"):::projected c7(["bd:serviceParam"]):::iri c2(["wd:Q5"]):::iri c9(["en"]):::literal c4(["wd:Q11696"]):::iri v1 --"wdt:P31"--> c2 v1 --"wdt:P39"--> c4 v1 --"wdt:P26"--> v2 subgraph s1["http://wikiba.se/ontology#label"] style s1 stroke-width:4px; c7 --"wikibase:language"--> c9 end