lilele12211104的专栏

Sorting by Field ValuesMultilevel SortingWhat Is Relevance?The standard similarity algorithm used in ES is known as a term frequency/ inverse document frequency, or TF/IDF, takes the following fa...

Exact Values Versus Full TextInverted IndexThe process of tokenization and normalization is called analysis.Testing AnalyzersCore Simple Field TypesWe can update a mapping to add a new f...

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Using Language AnalyzersConfiguring Language Analyzers

The standard analyzer is used by default for any full–text analyzed string field.Punctuation may or may not be considered part of a word, depending on where it appears:icu_tokenizerTidying up ...

lowercase filterLiving in a Unicode WorldUnicode Case FoldingSorting and CollationsCase-Insensitive SortingIn other words, we need an analyzer that will emit a single lowercase token:

Using an algorithmic StemmerDictionary StemmersInstead of applying a standard set of rules to each word, they simply look up the word in the dicitionary. Theoretically, they could produce much b...

index名称限制:小写字母不能包含,/ *,?”,<、> |“(空格字符),#7.0之前的索引可能包含冒号，但是不赞成这样做，7.0+不支持这样做不能以-，_，+开头不能。不能 .或者. .不能超过255字节(注意它是字节，所以多字节字符会更快地计算到255限制)...

Index Aliases and Zero DowntimeThe problem with the reindexing process described previously is that you need to update your application to use the new index name.An index alias is like a shortcut or...

Buckets and Metrics

Buckets inside BucketsLet’s take a look at the response.One Final ModificationLet’s add two metrics to calculate the in and max price for each make:Which gives us the following output...

Multiple Query StringsSingle Query StringThere is on simple one-size-fits-all approach to multiword, multifield queries. To get the best results, you have to know your data and know how to use the...

The match QueryMultiword QueriesImproving PrecisionControlling PrecisionCombining QueriesScore CalculationControlling PrecisionHow match Uses boolBoosting Query ClausesContro...

Search is executed in a two-phase process called query then fetch.Query PhaseDuring the initial query phase, the query is broadcast to a shard copy(a primay or replica shard) of every shard in the ...

Creating an IndexDeleting an IndexConfiguring AnalyzersTypes and MappingsA type consists of a name-- such as user or blogpost – and a mapping. The mapping, like a database schema, describes t...

Dynamicallly Updatable IndicesNear Real-Time SearchRefresh APIBy default, every shard is refreshed automatically once every second.Making Changes Persistentflush APISegment Merg...

Chapter 1Let’s Build an Employee DirectoryA single document represents a single employee.The act of stroring data in Elasticsearch is called indexing.You can draw some rough parallels to a tr...

Add an IndexIn reality, an index is just a logical namespace that points to one or more pyhsical shards.A shard is a single instance of Lucence, and is a complete search engine in its own right....

With Structured search, the answer to your question is always a yes or no; something either belongs in the set or it does not. Structured search does not worry about document relevance or scoring; it ...

The default English stopwordsThese stopwords can usually be filtered out before indexing with little negative impact on retrieval.But is is a good idea to do so?Pros and Cons of Stopwordsthe pri...

Using SynonymsFormatting SynonymsIn their simplest form, synonyms are listed as comma-separated values:“jump, leap, hop”If any of these terms is encountered, it is replaced by all of the listed s...

What is a Document?In Elasticsearch, document refers to the top-level, or root object that is serialized into JSON and stored in Elasticsearch under a unique ID._indexAn index is like a database i...

Routing a Document to a ShardCreating, Indexing, and Deleting a DocumentCreat, index and delete requests are write operations, which must be successfully completed on the primary shard before the...

The real power of Elasticsearch lies in its ability to make sense out of chaos – to turn Big Data into Big Information.A search can be any of the following:1. A structured query on concrete fields l...

Data TypeseditMost of Elasticsearch data types are available in Elasticsearch SQL, as indicated below:Elasticsearch type SQL type SQL precisionCore typesnullnull0booleanboolean1bytetinyint...