Help:CirrusSearch/it

Il modo più veloce per trovare informazioni nei progetti Wikimedia è di cercarle direttamente. In ogni pagina c'è una casella .

CirrusSearch è un'estensione MediaWiki che usa Elasticsearch per fornire funzionalità di ricerca migliorate rispetto alla ricerca predefinita di MediaWiki. La Wikimedia Foundation utilizza CirrusSearch in tutti i progetti Wikimedia. Questa pagina descrive le funzionalità di CirrusSearch. Se qui non trovi risposta alla tua domanda, sentiti libero di chiedere sulla pagina di discussione e qualcuno ti risponderà.

Per informazioni sull'estensione MediaWiki vedi Extension:CirrusSearch.

Come funziona
Inserisci parole chiave o frasi e premi il tasto Invio. Oppure clicca sull'icona della lente o sul tasto Ricerca. Se una pagina ha lo stesso titolo che hai cercato sarai subito rimandato a tale pagina. In caso contrario, cercherà tra tutte le pagine del wiki e presenterà un elenco di pagine che corrispondono ai tuoi termini di ricerca, o un messaggio per informarti che nessuna pagina ha tali parole chiave e frasi.

Se clicchi sul pulsante "" senza inserire nulla, sarai rimandato alla pagina Speciale:Ricerca che fornisce ulteriori opzioni di ricerca (comunque disponibili anche dalle pagine dei risultati di ricerca).

Può essere utile restringere una ricerca ad un particolare namespace, ad esempio solo all'interno delle pagine. Controlla i namespace che richiedi per questa ricerca.

Cos'è migliorato?
In confronto alla ricerca predefinita di MediaWiki, CirrusSearch offre tre principali miglioramenti, cioè:


 * Miglior supporto per la ricerca in diverse lingue.
 * Aggiornamenti più rapidi dell'indice di ricerca, cosa che rende più veloce l'assimilazione nei risultati delle modifiche effettuate.
 * Espansione dei template, il che significa che anche il contenuto dei template ora riflette i risultati delle ricerche.

Con quale frequenza è aggiornato l'indice di ricerca?
Gli aggiornamenti all'indice di ricerca sono eseguiti quasi in tempo reale. Le modifiche alle pagine dovrebbero apparire immediatamente nei risultati. Le modifiche ai template dovrebbero avere effetto sulle voci che li includono entro pochi minuti. Questo tipo di modifiche usa la coda di lavoro (job queue), pertanto le prestazioni possono variare. Una null edit all'articolo forzerà comunque l'aggiornamento ma non è richiesta se tutto procede per il verso giusto.

Suggerimenti di ricerca
I suggerimenti che si ottengono nel menu a tendina quando si digita qualcosa nella casella di ricerca sono ordinati in base ad una misurazione approssimata della qualità della voce. Questo tiene in conto il numero di wikilink in entrata, la dimensione della pagina, il numero di collegamenti esterni, il numero di sezioni e il numero di redirect. I suggerimenti possono essere ignorati e le ricerche indirizzeranno direttamente alla pagina dei risultati di ricerca. Basta aggiungere una tilde  prima della ricerca stessa. Ad esempio "~Frida Kahlo". I suggerimenti di ricerca continueranno ad apparire, ma premendo in qualsiasi momento il tasto Invio si verrà rimandati alla pagina dei risultati di ricerca.

Per la lingua inglese i caratteri con accenti o diacritici e quelli senza sono considerati lo stesso carattere ed i simboli Unicode sono convertiti in ASCII, ma vi sono alcuni problemi di formattazione con il risultato. Vedere.

Ricerca nel testo completo
Una "ricerca nel testo completo" (full test search) è una "ricerca indicizzata". Tutte le pagine sono salvate nel database wiki, e tutte le parole di queste pagine sono salvate in un database di ricerca, che è un indice al testo completo del wiki. Ogni parola visibile è indicizzata nella lista di pagine in cui può essere trovata, quindi la ricerca di una parola è veloce come se fosse fatta all'interno di un singolo documento. Oltretutto, per ogni cambiamento nelle parole, l'indice di ricerca è aggiornato entro qualche secondo.

Ci sono vari indici sul "testo completo" del wiki per facilitare le varie tipologie di ricerche di cui si ha bisogno. Il wikitesto completo è indicizzato varie volte i più indici a finalità speciali, ignuna interpretando il wikitesto nella maniera che ottimizza il loro uso. Un esempio di indicizzazione:


 * Il testo "ausiliario" che include annotazioni, didascalie, indici analitici ed ogni wikitesto classificato da un attributo HTML class=searchaux.
 * Il testo "introduttivo" che è il wikitesto fra la parte superiore della pagina e il primo di sezione.
 * Il testo "categoria" che indicizza la lista al fondo.
 * I template sono indicizzati. Se le parole nella transclusione cambiano, allora viene aggiornata ogni pagina che lo include. (Questo può richiedere parecchio tempo a seconda della coda di lavoro.) Se cambiano i sottotemplate usati dal template, l'indice è aggiornato.
 * I contenuti dei documenti che sono salvati nel namespace File/Media sono indicizzati. Sono riconosciuti migliaia di formati.

Sono supportate dozzine di lingue, sebbene l'obiettivo sia quello di gestire tutte le lingue. Vi è una lista delle lingue supportate su elasticsearch.org; vedere la loro documentazione per inviare richieste o correzioni.

CirrusSearch ottimizzerà la tua richiesta (query) e la effettuerà. I titoli risultanti sono pesati per rilevanza, e significativamente post-processati, 20 alla volta, per ogni pagina dei risultati di ricerca. Per esempio i frammenti di testo sono ottenuti dalla pagina, e i termini di ricerca sono evidenziati in grassetto.

I risultati di ricerca spesso saranno accompagnati da vari avvisi preliminari. Fra di essi vi è il Forse cercavi (correzione degli errori di battitura) e, quando non vi sarebbero risultati, vi sarà il Mostra risultati per (ricerca corretta) e cerca invece (la tua query).

Fra le varie funzionalità della ricerca:


 * Ordinamento dei suggerimenti di ricerca per numero di collegamenti in entrata.
 * Inizio con il carattere tilde  per disabilitare la navigazione e i suggerimenti in modo da preservare anche l'ordinamento delle pagine.
 * Normalizzazione dei caratteri non inseribili da tastiera in caratteri inseribili da tastiera.
 * Parole e frasi che corrispondono sono evidenziate in grassetto nelle pagine dei risultati. L'evidenziazione è un analizzatore superficiale, mentre sono gli indici di ricerca a trovare realmente le pagine, e quindi possono non corrispondere al 100%, specialmente per le espressioni regolari (regex). L'evidenziazione può essere più o meno accurata dell'indice.

Parole, frasi e modificatori
Una ricerca base è una parola o una "frase fra virgolette". La ricerca riconosce come "parola":


 * una stringa di numeri
 * una stringa di lettere
 * sottoparole fra transizioni di lettere/numeri, come in txt2regex
 * sottoparole dentro a nomiCombinati usando camelCase

Una "parola bloccata" (stop word) è una parola che è ignorata (perchè è troppo comune, o per altre ragioni). Un certo termine di ricerca trova corrispondenze nel contenuto (elaborato nella pagina). Per trovare corrispondenze nel wikitesto, usa il parametro di ricerca insource (vedi la sezione Insource più in fondo). Ogni parametro di ricerca ha il suo indice, e lo interpreta a modo suo.

La spaziatura fra le parole, frasi, parametri, e l'input dei parametri, può includere una generosa presenza di spazi bianchi e di spaziature grigie (greyspace characters). Le spaziature grigie sono tutti i caratteri non alfanumerici ~!@#$%^&_+-={}|[]\:";'<>?,./ . Una stringa composta dall'insieme di spaziature grigie e spazi bianchi è uno "spaziogrigio" (greyspace), ed è trattata come una grande parola limite. Lo spaziogrigio è come gli indici sono costruiti e come le query sono interpretate.

Le due eccezioni sono quando 1) embedded:colon è una parola (che viene trattata come una lettera, o sequenza alfabetica), e 2) è una virgola incorporata, come in 1,2,3 , che viene trattata come un numero, o sequenza numerica. I caratteri di spaziatura grigia vengono in ogni modo ignorati a meno ché, per la sintassi della query, possano essere interpretate come caratteri modificatori.

I modificatori sono ~ * \? - " ! . In base alla loro posizione nella sintassi possono essere applicati ad un termine, un parametro, o ad una intera query. I modificatori di parola e frase sono le ricerche jolly, o di prossimità o le ricerche ambigue e non definite. Ogni parametro può avere i propri modificatori, ma in generale:


 * A fuzzy-word or fuzzy-phrase search can suffix a tilde  character (and a number telling the degree).
 * A tilde  character prefixed to the first term of a query guarantees search results instead of any possible navigation.
 * A wildcard character inside a word can be a (escaped) question mark \? for one character or an asterisk * character for more.
 * Truth-logic can interpret AND and OR, but parameters cannot. Note that the AND and OR operators currently do not function in the traditional truth-logic manner! For details see more on logical operators.
 * Truth-logic understands - or ! prefixed to a term to invert the usual meaning of the term from "match" to "exclude".


 * Quotes around words mark an "exact phrase" search. For parameters they are also needed to delimit multi-word input.
 * Stemming is automatic but can be turned off using an "exact phrase".

Una ricerca di una frase può essere iniziata con diverse indicazioni al motore di ricerca. Ogni metodo di indicazione ha un effetto collaterale su quanto saranno precisi i risultati corrispondenti alla sequenza di parole. Indicazioni per greyspace, camelCase, o txt2number:

Un report di "cerca ivece" è attivata quando una parola universalmente sconosciuta viene ignorata in una frase.
 * given words-joined_by_greyspace(characters) or wordsJoinedByCamelCaseCharacters it finds words joined by ... characters, in their bare forms or greyspace forms.
 * txt2number will match  or.
 * Stop words are enabled for the edge cases (in the periphery) of a grey_space or camelCase phrase. An example using the, of , and a is that the_invisible_hand_of_a matches.

Oguna dei seguenti tipi di ricerca-frasi contiene o si estende oltre le tolleranze di riscontro della precedente:


 * Una "frase esatta" "virgolettata" tollererà (considererà) gli spazigrigi. Data una "exact_phrase" o "exact phrase" verrà trovata una.


 * Una grayspace_phrase avvia il controllo dei lemmi e delle "parole di stop"


 * Dato CamelCase sarà "in oltre" trovato, tutto in minuscolo, poiché CirrusSearch non è sensibile alle maiuscole nella ricerca.

Page ranking saves you from typing quotes for a two-word search. With no quotes a word-pair index is used in page-ranking, plus it finds the two words anywhere on the page.

Alcuni parametri interpretano frasi greyspace (frasi che possiedono caratteri non-alfanumerici), ma altri parametri, come  (fonte di informazione), interpretano soltanto la "frase tra virgolette" abituale.

Note that all stemming is case insensitive.

Noti come la ricerca della "frase esatta" ha interpretato il carattere embedded:colon come una lettera, ma non il carattere  embedded_underscore. Un simile evento avviene con il carattere, in un numero.

Given, CirrusSearch, when in an "exact phrase" context, (which includes the insource parameter context), will not match  ,  , or  , but will then only match.

Altrimenti ricorda che per CirrusSearch le parole sono lettere, numeri o combinazioni dei due e non contano le maiuscole/minuscole.

The common word search employs the space character and is aggressive with stemming, and when the same words are joined by greyspace characters or camelCase they are aggressive with phrases and subwords.

When common words like "of" or "the" are included in a greyspace-phrase, they are ignored, so as to match more aggressively.

A greyspace_phrase search term, or a camelCase, or a txt2number term, match the signified words interchangeably. You can use any of those three forms. Now camelcase matches camelCase because Search is not case sensitive, but camelCase matches camelcase because camelCase is more aggressive. Like the rest of Search, subword "words" are not case-sensitive. By comparison the "exact phrase" is greyspace oriented and ignores numeric or letter-case transitions, and stemming. "Quoted phrases" are not case sensitive.

From the table we can surmise that the basic search parser_function -"parser function" is the sum of the basic searches  and.

Making inquiries with numbers, we would find that:


 * Plan9 or Plan_9 matches any of:,  ,  ,  ,
 * "plan9" only matches  (case insensitive)
 * Plan*9 matches  or.

The star * wildcard matches a string of letters and digits within a rendered word, but never the beginning character. One or more characters, a percentage of the word, must precede the * character.


 * If the leading part is only letters then it will limit a match to a string of (zero of more) letters.
 * If only numbers, then it will limit a match to a sequence of (zero or more) numbers, including also ordinal letters (st, nd, rd), capital letters, or time abbreviations (am or pm); and it will match the entirety of (both sides of) a decimal numbers.
 * Otherwise the comma is considered part of one number, but the decimal point is considered a greyspace character, and will delimit two numbers.
 * Inside an "exact phrase" it matches stemming plus compounding.

The \? wildcard represents one letter or number; The *\? is also accepted, but \?* is not recognized.

The wildcards are for basic word, phrase, and insource searches, and may also be an alternative to (some) advanced regex searches (covered later).

Putting a tilde ~ character after a word or phrase activates a fuzzy search.


 * For a phrase it is termed a proximity search, because proximal words are tolerated to an approximate rather than exact phrase.
 * For example, "exact one two phrase"~2 matches.
 * For a word it means extra characters or changed characters.
 * For a phrase a fuzzy search requires a whole number telling it how many extra words to fit in, but for a word a fuzzy search can have a decimal fraction, defaulting to word~0.5 ( word~.5 ), where at most two letters can be found swapped, changed, or added, but never the first two letters.
 * For a proximity phrase, a large number can be used, but that is an "expensive" (slow) search.
 * For a word word~2 is most fuzzy with an edit distance of 2 (default), and word~1 is least fuzzy, and word~0 is not fuzzy at all.

For the closeness value necessary to match in reverse (right to left) order, count and discard all the extra words, then add twice the total count of remaining words minus one. (In other words, add twice the number of segments). For the full proximity algorithm, see Elasticsearch slop.

Le virgolette daranno come risultato l'esatto termine cercato. Puoi aggiungere una tilde ~ per rendere la ricerca più aggressiva.

Insource
Insource searches can be used to find any one word rendered on a page, but it's made for finding any phrase you might find - including MediaWiki markup, on any page except redirects. This phrase completely ignores greyspace: insource: "state state autocollapse" matches.

Insource complements itself. On the one hand it has full text search for any word in the wikitext, instantly. On the other hand it can process a regexp search for any string of characters. Regex scan all the textual characters in a given list of pages; they don't have a word index to speed things up, and the process is interrupted if it must run more than twenty seconds. Regex run last, so to limit needless character-level scanning, you advance it a list of pages (a search domain) selected by an indexed search added to the query as a "clause", and you do this to every single regex query. Insource can play both roles, and the best candidate for insource:/arg/ is often insource: arg, where arg is the same.

The syntax for the regexp is insource: no space, and then /regexp/. (No other parameter disallows a space. All the parameters except insource:/regexp/ generously accept space after their colon.)

Insource indexed-search and regexp-search roles are similar in many respects:


 * Both search wikitext only.
 * Neither finds things "sourced" by a transclusion.
 * Neither does stemmed, fuzzy, or proximity searches.
 * Both want the fewest results, and both work faster when accompanied by another clause.

But indexed searches all ignore greyspace; wildcards searches do not match greyspace, so regex are the only way to find an exact string of any and all characters, for example a sequence of two spaces. Regex are an entirely different class of search tool that make matching a literal string easy (basic, beginner use), and make matching by metacharacter expressions possible (advanced use) on the wiki. See below.

Prefix and namespace
For Search, a namespace term functions to specify the initial search domain. Instead of searching the entire wiki, the default is the main namespace (mainspace).

Only one namespace name can be set from the search box query. It is either the first term or in the last term, in a prefix parameter.

Two or more namespaces may be searched from the Advanced pane of the search bar found on the top of every search results page, Special:Search. Your search domain, as a profile of namespaces, can be set here. The namespaces list will then present itself on the first page of future search results to indicate the search domain of the search results. To unset this, select the default namespace (shown in parentheses), select "Remember", and press Search.

The search bar graphically sets and indicates a search domain. "Content pages" (mainspace), "Multimedia" (File), "Everything" (all plus File), "Translations", etc., are hyperlinks that can activate the query in that domain, and then indicate this by going inactive (dark). But the query will override the search bar. When a namespace or prefix is used in the query the search bar activations and indications may be misleading, so the search bar and the search box are mutually exclusive (not complementary) ways to set the search domain.

A namespace term overrides the search bar, and a prefix term overrides a namespace.

Enter a namespace name, or enter, or enter a     colon for mainspace. All does not include the File namespace. File includes media content held at Commons such as PDF, which are all indexed and searchable.

When File is involved, a namespace modifier  has an effect, otherwise it is ignored.

Namespace aliases are accepted.

As with search parameters, local and all must be lowercase. Namespaces names are case insensitive.

The prefix: parameter matches any number of first-characters of all pagenames in one namespace. When the first letters match a namespace name and colon, the search domain changes.

Given a namespace only, prefix will match all its pagenames. Given one character only, it cannot be - dash or ' quote or " double quote. The last character cannot be a colon.

For pagenames that match, their subpage titles match by definition.

The prefix parameter does not allow a space before a namespace, but allows whitespace before a pagename.

The prefix parameter goes at the end so that pagename characters may contain " quotation marks.

The Translate extension creates a sort of "language namespace", of translated versions of a page. But unlike namespace or prefix, which create the initial search domain, the inlanguage parameter is a filter of it. (See the next section.)

Exclude content from the search index
Content can be excluded from the search index by adding. This will instruct CirrusSearch to ignore this content from the search index (see for more context).

Additionally content can be marked as auxiliary information by adding. This will instruct CirrusSearch to move the content from the main text to an auxiliary field which has lower importance for search and snippet highlighting. This distinction is used for items such as image thumbnail descriptions, 'see also' sections, etc.

Filters
A filter can have multiple instances, and negated instances, and it can run as a standalone filtering a search domain. A query is formed as terms that filter a search domain. A namespace or a prefix term is not a filter because a namespace will not run standalone, and a prefix will not negate.

Adding another word, phrase, or parameter filters more. A highly refined search result may have very many Y/N filters when every page in the results will be addressed. (In this case ranking is largely irrelevant.) Filtering applies critically to adding a regex term; you want as few pages as possible before adding a regex (because it can never have a prepared index for its search).

The search parameters below are filters.

Insource (covered above) is also a filter, but insource:/regexp/ is not a filter. Filters and all other search parameters are lowercase. (Namespaces are an exception, being case insensitive.)

Intitle e incategory
Word and phrase searches match in a title and match in the category box on bottom of the page. But with these parameters you can select titles only or category only. Intitle and incategory are old search parameters. Incategory no longer searches any subcategory automatically, but you can now add multiple category pagenames manually.
 * cow*
 * Find articles whose title or text contains words that start with cow
 * intitle:foo
 * Find articles whose title contains foo. Stemming is enabled for foo.
 * intitle:"fine line"
 * Find articles whose title contains fine line. Stemming is disabled.
 * intitle:foo bar
 * Find articles whose title contains foo and whose title or text contains bar.
 * -intitle:foo bar
 * Trova le voci il cui titolo non contiene "foo" e il cui titolo o il testo contiene "bar".
 * incategory:Music
 * Trova le voci che sono in Category:Music
 * incategory:"music history"
 * Trova le voci che sono in Category:Music_history
 * incategory:"musicals" incategory:"1920"
 * Find articles that are in both Category:Musicals and Category:1920
 * -incategory:"musicals" incategory:"1920"
 * Find articles that are not in Category:Musicals but are in Category:1920

Since Regular expression searches are supported for intitle:
 * intitle:/regex/, intitle:/regex/i

Everything written in the #Regular expression searches is also valid for these searches, including warnings.

Deepcategory
Deep category search allows to search in category and all subcategories. The depth of the tree is limited by 5 levels currently (configurable) and the number of categories is limited by 256 (configurable). The deep search uses SPARQL Category service from WDQS. Keywords are deepcategory or deepcat. Example:

Previously this parameter was implemented by a gadget: to get the search parameter deepcat, to automatically add up to 70 subcategories onto an incategory parameter, incategory:category1|category2|...|category70 , you can add a line to your Custom JavaScript.
 * deepcat:"musicals"
 * Find articles that are in Category:Musicals or any of the subcategories.

Linksto
Linksto finds wikilinks to a given name, not links to content. The input is the canonical, case sensitive, page name. It must match the title line of the content page, exactly, before any title modifications of the letter-case. (It must match its { {FULLPAGENAME}}, e.g. .)

Linksto does not find redirects. It only finds [ [wikilinks]], even when they are made by a template. It does not find a link made by a URL, even if that URL is an internal wiki link.

To find all wikilinks to a "Help:Cirrus Search", if "Help:Searching" and "H:S" are redirects to it:
 * 1) linksto: "Help:Cirrus Search"
 * 2) linksto: Help:Searching
 * 3) linksto: H:S

finds articles that mention "CirrusSearch" but not in a wikilink.

Hastemplate
You can specify template usage with. Input the canonical pagename to find all usage of the template, but use any of its redirect pagenames finds just that naming. Namespace aliases are accepted, capitalization is entirely ignored, and redirects are found, all in one name-search. (Compare boost-template no default namespace; linksto no namespace aliases, case-sensitive, no redirects; intitle no redirects.)

Hastemplate finds secondary (or meta-template) usage on a page: it searches the post-expansion inclusion. This is the same philosophy as for words and phrases from a template, but here it's for templates from a template. The page will be listed as having that content even though that content is not seen in the wikitext.


 * hastemplate: "quality image", finds "Template:Quality image" usage in your default search domain (namespaces).
 * hastemplate: portal:contents/tocnavbar, finds mainspace usage of a "Contents/TOCnavbar" template in the Portal namespace.

For installations with the Translate extension, hastemplate searches get interference wherever Template:Translatable template name wraps the template name of a translatable template. Use insource instead.

Inlanguage
For installations with the Translate extension, inlanguage is important for highly refined searches and page counts.


 * inlanguage: language code

will produce search results in that language only.

For example


 * to count all Japanese pages on the wiki
 * all: inlanguage: ja


 * to filter out German and Spanish pages in the Help namespace
 * help: -inlanguage: de -inlanguage: es


 * to ignore Translate, and where English is the base language, add
 * inlanguage:en

Contentmodel
The contentmodel: keyword allows to limit the search to pages of a specific content model. For possible models cf. Content handlers. E.g.:


 * To see only JSON pages:
 * contentmodel:json

subpageof
To find sub-pages.
 * subpageof: ParentPage

For example


 * To find all subpages of CirrusSearch.
 * subpageof:CirrusSearch


 * Use double quotes if the parent page contains spaces.


 * subpageof:"Requests for comment"

Page weighting
Weighting determines snippet, suggestions, and page relevance. The normal weight is one. Additional weighting is given through multipliers.

If the query is just words, pages that match them in order are given a boost. If you add any explicit phrases to your search, or for certain other additions, this "prefer phrase" feature is not applied.

Morelike
morelike is a "greedy" keyword, meaning that it cannot be combined with other search queries. If you want to use other search queries, use morelikethis in your search:
 * morelike:page name 1|page name 2|...|page name n
 * Ricerca tra gli articoli quale ha il contenuto più simile ai primi due articoli ricercati.
 * morelike:wasp|bee|ant
 * Find articles about stinging insects.
 * morelike:template:search|template:regex|template:usage
 * Find templates about regex searching for template usage on the wiki.
 * morelikethis:bee hastemplate:"featured article"
 * Find articles about bees that also have the "featured article" template.

The morelike: query works by choosing a set of words in the input articles and run a query with the chosen words. You can tune the way it works by adding the following parameters to the search results URL:

These settings can be made persistent by overriding  in System message.
 * cirrusMltMinDocFreq : Minimum number of documents (per shard) that need a term for it to be considered.
 * cirrusMltMaxDocFreq : Maximum number of documents (per shard) that have a term for it to be considered.
 * cirrusMltMaxQueryTerms : Maximum number of terms to be considered.
 * cirrusMltMinTermFreq : Minimum number of times the term appears in the input to doc to be considered. For small fields ( title ) this value should be 1.
 * cirrusMltMinWordLength : Minimal length of a term to be considered. Defaults to 0.
 * cirrusMltMaxWordLength : The maximum word length above which words will be ignored. Defaults to unbounded (0).
 * cirrusMltFields (comma separated list of values): These are the fields to use. Allowed fields are title, text , auxiliary_text , opening_text , headings and all.
 * cirrusMltUseFields ( | ): use only the field data. Defaults to : the system will extract the content of the   field to build the query.
 * cirrusMltPercentTermsToMatch : The percentage of terms to match on. Defaults to 0.3 (30 percent).
 * Example:

Prefer-recent
Adding prefer-recent: anywhere in the query gives recently edited articles a slightly larger than normal boost in the page-ranking rules. Prefer-recent is only applied when using the default  sort order.

It defaults to boost only 60% of the score, in a large, 160 day window of time, which can be entered in the query as prefer-recent:0.6,160. This plays well with other page ranking rules, and is intended for most searches.

You can manipulate the rules: prefer-recent:boost,recent Technically "boost" is the proportion of score to scale, and "recent" is the half life in days. The boost is more than the usual multiplier, it is an exponential boost. The factor used in the exponent is the time since the last edit.

For example
 * prefer-recent:,7

Pages older than 7 days are boosted half as much, and pages older than 14 days are boosted half as much again, and so on. For a simple "sort by date" in highly refined search results, where page ranking and boosting are largely meaningless, just boost the entire score.
 * prefer-recent:1,7 (weeks)
 * prefer-recent:1,1 (days)
 * prefer-recent:1,0.0007 (minutes)
 * prefer-recent:1,0.0001 (8.64 seconds)
 * prefer-recent:1,0.00001 (seconds)

Boost-templates
Puoi anche dare priorità alle pagine basandoti sui template in esse contenuti. Ciò può essere fatto direttamene scrivendo  o puoi decidere che ciò avvenga di default per ogni ricerca inserendo. Il codice  sostituisce il contenuto di   se il primo è esplicitato. La sintassi è un po' bizzarra ma è stata scelta per questioni di semplicità. Like prefer-recent, boost-templates is only applied when using the default  sort order. Alcuni esempi:


 * File:boost-templates:"Template:Quality Image|200%" incategory:china
 * Cercherà le immagini della categoria Cina che abbiano anche il template "Quality Image"


 * File:boost-templates:"Template:Quality Image|200% Template:Low Quality|50%" incategory:china
 * Troverà le immagini nella categoria Cina visualizzando prima quelle d'alta qualità e poi quelle di bassa qualità.


 * File:boost-templates:"Template:Quality Image|200% Template:Low Quality|50%" popcorn
 * Find files about popcorn sorting quality images first and low quality images last. Remember that through the use of the  message this can be reduced to just.

Non inserire un decimale nelle percentuali. Non funzionano con questo sistema di ricerca e restituirà un risultato indesiderato.

Una nota il merita il codice : se aggiungi percentuali molto piccole o molto grandi esse possono contaminare il risultato della ricerca. Pensa per esempio se su en.wikipedia volessi dare priorità ad una percentuale molto molto alta di articoli in vetrina. In questo caso le ricerche per un dato termine visualizzerebbero solo articoli in vetrina contenenti quel nome anche se magari esiste una pagina con l'esatto titolo della ricerca ma non viene visualizzato perché non in vetrina.

Regular expression searches
A basic indexed-search finds words rendered visible on a page. Hyphenation and punctuation marks and bracketing, slash and other math and computing symbols, are merely boundaries for the words. It is not possible to include them in an indexed search.

These return much much faster when you limit the regexp search-domain to the results of one or more index-based searches.

An "exact string" regexp search is a basic search; it will simply "quote" the entire regexp, or "backslash-escape" all non-alphanumeric characters in the string. All regexp searches also require that the user develop a simple filter to generate the search domain for the regex engine to search:


 * insource:"debian.reproducible.net" insource: / debian\.reproducible\.net / 
 * insource:"c:\program files (x86)" insource: / C\:\\Program Files \(x86\) /i 
 * insource:"{ {template}}" insource: / "{ {template}}<\/tag>" /
 * insource:"[ [title|link label]]'s" insource: / "[ [title|link label]]'s" /
 * insource: / regexp / prefix:{ {FULLPAGENAME}}

The last example works from a link on a page, but { {FULLPAGENAME}} doesn't function in the search box.

For example: Special:Search/insource:/regex/ prefix: finds the term regex on this page.

A query with no namespace specified and no prefix specified searches your default search domain, (settable on any search-results page, i.e. at Special:Search). Some users keep their default search domain at "all namespaces", i.e. the entire wiki. On a large wiki if this user does a bare regexp search it will probably fail, incurring an HTML timeout, before completing the search.

A regex search actually scours each page in the search domain character-by character. By contrast, an indexed search actually queries a few records from a database separately maintained from the wiki database, and provides nearly instant results. So when using an insource:// (a regexp of any kind), consider creating one the other search terms that will limit the regex search domain as much as possible. There are many search terms that use an index and so instantly provide a more refined search domain for the /regexp/. In order of general effectiveness:


 * insource:"" with quotation marks, duplicating the regexp except without the slashes or escape characters, is ideal.
 * intitle (without regex search), incategory, and linksto are excellent filters.
 * hastemplate: is a very good filter.
 * "word1 word2 word3", with or without the quotation marks, are good.
 * namespace: is practically useless, but may enable a slow regexp search to complete.

To test a bare regexp query you can create a page with test patterns, and then use the prefix parameter with that fullpagename. The match will be highlighted. It searches that page (in the database) and its subpages.

Search terms that do not increase the efficiency of a regexp search are the page-scoring operators: morelike, boost-template, and prefer-recent.

Metacharacters
This section covers how to escape metacharacters used in rexexp searches For the actual meaning of the metacharacters see the explanation of the syntax.

For example:


 * to search a namespace, gauge the number of pages with a single term that is a namespace. This will list the number of pages in that namespace.
 * starting out to find again what you may have seen, like "wiki-link" or "(trans[in]clusion)" start with namespace and insource filters.

Refining with an exact string

 * refinining an ongoing search process with what you want to see, like "2 + 2 = 4", or "site.org" This is ideally the best use of regex, because it adds it as a single regexp term while refining a search, the limited number of pages the regexp must crawl is can be seen.

You can start out intending an exact string search, but keep in mind:


 * regex only search the wikitext not the rendered text, so there are some differences around the markup, and even the number of space characters must match precisely.
 * You are obligated to supply an accompanying filter.
 * You must learn how to escape regex metacharacters.

There are two ways to escape metacharacters. They are both useful at times, and sometimes concatenated side-by-side in the escaping of a string.


 * Backslash-escape one of them \char. The insource:/regexp/ uses slashes to delimit the regexp. Giving /reg/exp/ is ambiguous, so you must write /reg\/exp/.
 * Put a string of them in double quotes "string". Because escaping a character can't hurt, you can escape any character along with any possible metacharacters in there. Escaping with quotes is cleaner.
 * You can't mix methods, but you can concatenate them.

Double-quotes escaping using insource:/"regexp"/ is an easy way to search for many kinds of strings, but you can't backslash-escape anything inside a double-quoted escape.


 * instead of
 * is as good as
 * But  always.
 * And .  It finds the   literally, which is not the   you probably wanted.

Backslash-escape using insource:/regexp/ allows escaping the " and / delimiters, but requires taking into account metacharacters, and escaping any:


 * To match a  delimiter character use.
 * To match a  delimiter character use.
 * The escaped metacharacters would be.
 * The equivalent expression escaped with double-quotes is.

The simplest algorithm to create the basic string-finding expression using insource:/"regexp"/, need not take metacharacters into account except for the " and / characters:
 * 1) Write   out. (The /" delimiters "/ are not shown.)
 * 2) Replace   with   (previous double-quote: stop, concatenate, quote restart).
 * 3) Replace   with   (stop, concatenate, start).
 * 4) You get , showing concatenation of the two methods.

The square-bracket notation for creating your own character-class also escapes its metacharacters. To target a literal right square bracket in your character-class pattern, it must be backslash escaped, otherwise it can be interpreted as the closing delimiter of the character-class pattern definition. The first position of a character class will also escape the right square bracket. Inside the delimiting square brackets of a character class, the dash character also has special meaning (range) but it too can be included literally in the class the same way as the right square bracket can. For example both of these patterns target a character that is either a dash or a right square bracket or a dot:  or.

For general examples using metacharacters:


 * insource:"2+2=4" insource:/"2+2=4"/ matches "2 + 2 = 4", with zero spaces between the characters.
 * insource:"2 + 2 = 4" insource:/2 ?\+ ?2 ?= ?4\./ match with zero or one space in between. The equals = sign is not a metacharacter, but the plus + sign is.
 * insource:"[ [link|2\3?]]\" insource:/"[ [link|2\3?]]< "\/" tag>"/

There are some notable differences from standard regex metacharacters:


 * The  or   are not reserved for matching a newline. To search for a string that contains a newline, you can do a search like   which means not a curly brace, then two curly braces, then any two characters except a curly brace, space, or pipe, then a  tag. The "any character except" will include a newline in the search. Note thas this search was designed only to match to the following string:


 * The dot . metacharacter stands for any character including a newline, so .* matches across lines.
 * The number # sign means something, and must be escaped.
 * The ^ and $ are not needed. Like "grep" (global per line, regular expression, print each line), each insource:// is a "global per document, regular expression, search-results-list each document" per document.
 * support a multi-digit numeric range like [0-9] does, but without regard to the number of character positions, or the range in each position, so <9-10> works, and even <1-111> works.

Regex on titles
The insource keyword does only search the page source content. To run regex searches on the title strings intitle:/regex/ can be used.

Advanced example
For example, using metacharacters to find the usage of a template called Val having, inside the template call, an unnamed parameter containing a possibly signed, three to four digit number, possibly surrounded by space characters, and on the same page, inside a template Val call, a named argument  having any allowable spaces around it, (it could be the same template call, or a separate one):



Note that the = sign in "fmt commas" is not needed but that adding it would not change the search results. It is fast because it uses two filters so that every page the regexp crawls has the highest possible potential.

bounded
You can limit search to pages identified as being near some specified geographic coordinates. The coordinates can either be specified as a, pair, or by providing a page title from which to source the coordinates. A distance to limit the search to can be prepended if desired. Examples:


 * neartitle:"San Francisco"
 * neartitle:"100km,San Francisco"
 * nearcoord:37.77666667,-122.39
 * nearcoord:42km,37.77666667,-122.39

boosted
You can alternatively increase the score of pages within a specified geographic area. The syntax is the same as bounded search, but with boost- prepended to the keyword. This effectively doubles the score for pages within the search range, giving a better chance for nearby search results to be near the top.


 * boost-neartitle:"San Francisco"
 * boost-neartitle:"100km,San Francisco"
 * boost-nearcoord:37.77666667,-122.39
 * boost-nearcoord:42km,37.77666667,-122.39

File properties search
Since MediaWiki 1.28, CirrusSearch supports indexing and searching of properties of files in the  namespace. This includes:
 * file media type
 * MIME type
 * size
 * width & height
 * resolution
 * bit depth for files that support these

filetype
Searching for file type allows to retrieve files according to their classification, such as office documents, videos, raster images, vector images, etc. The following types currently exist:



This list may be extended in the future. See also  constants in.

The syntax of the search is: filetype:{type}. Example:

filetype:video - looks for all videos

The filetype search is not case-sensitive.

filemime
Matches file MIME type. The syntax is:

filemime:{MIMEtype} - look for files of this MIME type

The argument can be quoted to specify exact match. Without quotes, partial matches to components of MIME type will be accepted too.

Examples:

filemime:"image/png" - look for files with MIME type exactly

filemime:pdf - look for all PDF documents

The MIME type search is not case sensitive.

filesize
Search for file of given size, in kilobytes (kilobyte means 1024 bytes). The syntax is:

filesize:{number} or filesize:>{number} - file with size at least given number

filesize:<{number} - file with size no more than given number

filesize:{number},{number} - file with size between given numbers

Examples:

filesize:>20 or filesize:20 - files 20KB and bigger

filesize:<1024 - files smaller than 1MB

filesize:100,500 - files with sizes between 100KB and 500KB

File measures
It is possible to search for specific file measures: width, height, resolution (which is defined as square root of height × width), and bit depth. Not all files may have these properties. The syntax is:

{measure}:{number} - file with measure that equals to given number

{measure}:>{number} - file with measure that is at least given number

{measure}:<{number} - file with measure that is no more than given number

{measure}:{number},{number} - file with measure that is between given numbers

Where  can be:

filew or filewidth - file width

fileh or fileheight - file height

fileres - file resolution (see above)

filebits - file bit depth

Examples:

filew:>800 fileh:>600 - files that are at least 800x600 pixels in size

filebits:16 - files with 16-bit color depth

fileheight:100,500 - file between 100 and 500 pixels high

Wikibase search
extension defines some search keywords in order to make it easier to search for certain Wikibase items. Currently this is useful only on sites. See for details.

Cross-wiki search results
The search on Wikimedia projects includes improved cross-wiki search results (also known as interwiki search results, sister projects search results).

Explicit sort orders
In addition to the default relevance based sort CirrusSearch can provide results a few other explicit sort orders. Specifying a sorting order other than  will disable all search keywords that affect scoring, such as   or. The keywords will still be parsed, but they will have no effect.

Sorting options are currently available from the MediaWiki API by providing the  parameter.

Sorting options can be manually added to a search URL by adding, for example https://www.mediawiki.org/w/index.php?search=foo&sort=last_edit_desc.

Valid sort orders include:

Interface for advanced options


The AdvancedSearch extension adds an improved interface to the search page allowing the use of several options described above in a user-friendly manner. See here for the user manual.

Vedi anche

 * Completion Suggester - the incremental search feature of CirrusSearch
 * Wikimedia Discovery/Search/Glossary - definitions, context, and links for terms related to search.
 * See Search/Old for more on the development and debut of of CirrusSearch.
 * See Help:Searching for MWSearch, used by the many wikis that don't have a search extension.
 * See Help:Searching for MWSearch, used by the many wikis that don't have a search extension.