2020-12-11 leiting (3373阅读)
Elasticsearch ships with a wide range of built-in analyzers, which can be used in any index without further configuration:
standard analyzer divides text into terms on word boundaries, as defined by the Unicode Text Segmentation algorithm. It removes most punctuation, lowercases terms, and supports removing stop words.
simple analyzer divides text into terms whenever it encounters a character which is not a letter. It lowercases all terms.
whitespace analyzer divides text into terms whenever it encounters any whitespace character. It does not lowercase terms.
stop analyzer is like the
simple analyzer, but also supports removal of stop words.
keyword analyzer is a “noop” analyzer that accepts whatever text it is given and outputs the exact same text as a single term.
pattern analyzer uses a regular expression to split the text into terms. It supports lower-casing and stop words.
Elasticsearch provides many language-specific analyzers like
fingerprint analyzer is a specialist analyzer which creates a fingerprint which can be used for duplicate detection.