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ALTER TEXT SEARCH CONFIGURATION

Updated at: Mar 13, 2020 GMT+08:00

Function

ALTER TEXT SEARCH CONFIGURATION modifies the definition of a text search configuration. You can modify its mappings from token types to dictionaries, change the configuration's name or owner, or modify the parameters.

The ADD MAPPING FOR form installs a list of dictionaries to be consulted for the specified token types; an error will be generated if there is already a mapping for any of the token types.

The ALTER MAPPING FOR form removes existing mapping for those token types and then adds specified mappings.

ALTER MAPPING REPLACE ... WITH ... and ALTER MAPPING FOR... REPLACE ... WITH ... options replace old_dictionary with new_dictionary. Note that only when pg_ts_config_map has tuples corresponding to maptokentype and old_dictionary, the update will succeed. If the update fails, no messages are returned.

The DROP MAPPING FOR form deletes all dictionaries for the specified token types in the text search configuration. If IF EXISTS is not specified and the string type mapping specified by DROP MAPPING FOR does not exist in text search configuration, an error will occur in database.

Precautions

  • If a search configuration is referenced (to create an index), users are not allowed to modify it.
  • To use ALTER TEXT SEARCH CONFIGURATION, you must be the owner of the configuration.

Syntax

  • Add text search configuration string mapping.
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ALTER TEXT SEARCH CONFIGURATION name 
    ADD MAPPING FOR token_type [, ... ] WITH dictionary_name [, ... ];
  • Modify the text search configuration dictionary syntax.
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ALTER TEXT SEARCH CONFIGURATION name 
    ALTER MAPPING FOR token_type [, ... ] REPLACE old_dictionary WITH new_dictionary;
  • Modify the text search configuration string.
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ALTER TEXT SEARCH CONFIGURATION name
    ALTER MAPPING FOR token_type [, ... ] WITH dictionary_name [, ... ];
  • Change the text search configuration dictionary.
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ALTER TEXT SEARCH CONFIGURATION name
    ALTER MAPPING REPLACE old_dictionary WITH new_dictionary;
  • Remove text search configuration string mapping.
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ALTER TEXT SEARCH CONFIGURATION name
    DROP MAPPING [ IF EXISTS ] FOR token_type [, ... ];
  • Rename the owner of text search configuration.
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ALTER TEXT SEARCH CONFIGURATION name OWNER TO new_owner;
  • Rename the name of text search configuration.
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ALTER TEXT SEARCH CONFIGURATION name RENAME TO new_name;
  • Rename the namespace of text search configuration.
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ALTER TEXT SEARCH CONFIGURATION name SET SCHEMA new_schema;
  • Modify the attributes of text search configuration.
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ALTER TEXT SEARCH CONFIGURATION name SET ( { configuration_option = value } [, ...] );
  • Reset the attributes of text search configuration.
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ALTER TEXT SEARCH CONFIGURATION name RESET ( {configuration_option} [, ...] );

Parameter description

  • name

    Specifies the name (optionally schema-qualified) of an existing text search configuration.

  • token_type

    Specifies the name of a token type that is emitted by the configuration's parser. For details, see Parsers.

  • dictionary_name

    Specifies the name of a text search dictionary to be consulted for the specified token types. If multiple dictionaries are listed, they are consulted in the specified order.

  • old_dictionary

    Specifies the name of a text search dictionary to be replaced in the mapping.

  • new_dictionary

    Specifies the name of a text search dictionary to be substituted for old_dictionary.

  • new_owner

    Specifies the new owner of the text search configuration.

  • new_name

    Specifies the new name of the text search configuration.

  • new_schema

    Specifies the new schema for the text search configuration.

  • configuration_option

    Text search configuration option. For details, see CREATE TEXT SEARCH CONFIGURATION.

  • value

    Specifies the value of text search configuration option.

Examples

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-- Create a text search configuration:
CREATE TEXT SEARCH CONFIGURATION english_1 (parser=default);
CREATE TEXT SEARCH CONFIGURATION

-- Add text search configuration string mapping:
ALTER TEXT SEARCH CONFIGURATION english_1 ADD MAPPING FOR word WITH simple,english_stem;
ALTER TEXT SEARCH CONFIGURATION

-- Add text search configuration string mapping:
ALTER TEXT SEARCH CONFIGURATION english_1 ADD MAPPING FOR email WITH english_stem, french_stem;
ALTER TEXT SEARCH CONFIGURATION

-- Query information about the text search configuration:
SELECT b.cfgname,a.maptokentype,a.mapseqno,a.mapdict,c.dictname FROM pg_ts_config_map a,pg_ts_config b, pg_ts_dict c WHERE a.mapcfg=b.oid AND a.mapdict=c.oid AND b.cfgname='english_1' ORDER BY 1,2,3,4,5;
  cfgname  | maptokentype | mapseqno | mapdict |   dictname   
-----------+--------------+----------+---------+--------------
 english_1 |            2 |        1 |    3765 | simple
 english_1 |            2 |        2 |   12960 | english_stem
 english_1 |            4 |        1 |   12960 | english_stem
 english_1 |            4 |        2 |   12964 | french_stem
(4 rows)

-- Add text search configuration string mapping:
ALTER TEXT SEARCH CONFIGURATION english_1 ALTER MAPPING REPLACE french_stem with german_stem;
ALTER TEXT SEARCH CONFIGURATION

-- Query information about the text search configuration:
SELECT b.cfgname,a.maptokentype,a.mapseqno,a.mapdict,c.dictname FROM pg_ts_config_map a,pg_ts_config b, pg_ts_dict c WHERE a.mapcfg=b.oid AND a.mapdict=c.oid AND b.cfgname='english_1' ORDER BY 1,2,3,4,5;
  cfgname  | maptokentype | mapseqno | mapdict |   dictname   
-----------+--------------+----------+---------+--------------
 english_1 |            2 |        1 |    3765 | simple
 english_1 |            2 |        2 |   12960 | english_stem
 english_1 |            4 |        1 |   12960 | english_stem
 english_1 |            4 |        2 |   12966 | german_stem
(4 rows)

See Examples in CREATE TEXT SEARCH CONFIGURATION.

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