CREATE TEXT SEARCH CONFIGURATION

Function

CREATE TEXT SEARCH CONFIGURATION creates a text search configuration. A text search configuration specifies a text search parser that can divide a string into tokens, plus dictionaries that can be used to determine which tokens are of interest for searching.

Precautions

• If only the parser is specified, then the new text search configuration initially has no mappings from token types to dictionaries, and therefore will ignore all words. Subsequent ALTER TEXT SEARCH CONFIGURATION commands must be used to create mappings to make the configuration useful. If COPY option is specified, the parser, mapping and configuration option of text search configuration is copied automatically.
• If the schema name is specified, the text search configuration is created in the specified schema. Otherwise, the text search configuration is created in the current schema.
• The user who defines a text search configuration becomes its owner.
• PARSER and COPY options are mutually exclusive, because when an existing configuration is copied, its parser selection is copied too.

Syntax

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CREATE TEXT SEARCH CONFIGURATION name 
    ( PARSER = parser_name | COPY = source_config )
    [ WITH ( {configuration_option = value} [, ...] )];

Parameter Description

• name

  Specifies the name of the text search configuration to be created. Specifies the name can be schema-qualified.

• parser_name

  Specifies the name of the text search parser to use for this configuration.

• source_config

  Specifies the name of an existing text search configuration to copy.

• configuration_option

  Specifies the configuration parameter of text search configuration is mainly for the parser executed by parser_name or contained by source_config.

  Value range: The default, ngram, and zhparser parsers are supported. The parser of default type has no corresponding configuration_option. Table 1 lists configuration_option for ngram and zhparser parsers.

  Table 1 Configuration parameters for ngram and zhparser parsers

  Parser	Parameters for adding an account	Description	Value Range
  ngram	gram_size	Length of word segmentation	Integer, 1 to 4 Default value: 2
  	punctuation_ignore	Whether to ignore punctuations	true (default value): Ignore punctuations. false: Do not ignore punctuations.
  	grapsymbol_ignore	Whether to ignore graphical characters	true: Ignore graphical characters. false (default value): Do not ignore graphical characters.
  zhparser	punctuation_ignore	Whether to ignore special characters including punctuations (\r and \n will not be ignored) in the word segmentation result	true (default value): Ignore all the special characters including punctuations. false: Do not ignore all the special characters including punctuations.
  	seg_with_duality	Whether to aggregate segments with duality	true: Aggregate segments with duality. false (default value): Do not aggregate segments with duality.
  	multi_short	Whether to execute long words composite divide	true (default value): Execute long words composite divide. false: Do not execute long words composite divide.
  	multi_duality	Whether to aggregate segments in long words with duality	true: Aggregate segments in long words with duality. false (default value): Do not aggregate segments in long words with duality.
  	multi_zmain	Whether to display key single words individually	true: Display key single words individually. false (default value): Do not display key single words individually.
  	multi_zall	Whether to display all single words individually.	true: Display all single words individually. false (default value): Do not display all single words individually.

Examples

Create a text search configuration:

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DROP TEXT SEARCH CONFIGURATION IF EXISTS ngram1;
CREATE TEXT SEARCH CONFIGURATION ngram1 (parser=ngram) WITH (gram_size = 2, grapsymbol_ignore = false);

Create a text search configuration:

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DROP TEXT SEARCH CONFIGURATION IF EXISTS ngram2;
CREATE TEXT SEARCH CONFIGURATION ngram2 (copy=ngram1) WITH (gram_size = 2, grapsymbol_ignore = false);

Create a text search configuration:

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DROP TEXT SEARCH CONFIGURATION IF EXISTS english_1;
CREATE TEXT SEARCH CONFIGURATION english_1 (parser=default);

Helpful Links

ALTER TEXT SEARCH CONFIGURATION, DROP TEXT SEARCH CONFIGURATION