ALTER TEXT SEARCH CONFIGURATION

Function

This syntax modifies the definition of a text search configuration.

Users can update the mapping from string type to dictionary, change the configuration's name or owner, and adjust the search configuration parameters.

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 a mapping for text search.

       
            ALTER TEXT SEARCH CONFIGURATION name 
    ADD MAPPING FOR token_type [, ... ] WITH dictionary_name [, ... ];

Modify the text search configuration dictionary.

       
            ALTER TEXT SEARCH CONFIGURATION name 
    ALTER MAPPING FOR token_type [, ... ] REPLACE old_dictionary WITH new_dictionary;

Change the text search configuration mapping.

       
            ALTER TEXT SEARCH CONFIGURATION name
    ALTER MAPPING FOR token_type [, ... ] WITH dictionary_name [, ... ];

Change the text search configuration dictionary.

       
            ALTER TEXT SEARCH CONFIGURATION name
    ALTER MAPPING REPLACE old_dictionary WITH new_dictionary;

Delete the mapping of the text search configuration.

       
            ALTER TEXT SEARCH CONFIGURATION name
    DROP MAPPING [ IF EXISTS ] FOR token_type [, ... ];

Change the owner of the text search configuration.

       
            ALTER TEXT SEARCH CONFIGURATION name OWNER TO new_owner;

Rename the text search configuration.

       
            ALTER TEXT SEARCH CONFIGURATION name RENAME TO new_name;

Rename the text search configuration schema.

       
            ALTER TEXT SEARCH CONFIGURATION name SET SCHEMA new_schema;

Modify the attributes of the text search configuration.

       
            ALTER TEXT SEARCH CONFIGURATION name SET ( { configuration_option = value } [, ...] );

Reset the text search configuration attributes.

       
            ALTER TEXT SEARCH CONFIGURATION name RESET ( {configuration_option} [, ...] );

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.

Parameter Description

**Table 1** ALTER TEXT SEARCH CONFIGURATION parameters
Parameter	Description	Value Range
name	Specifies the name of the text search configuration to be modified, which can include a schema.	-
token_type	Specifies the name of the token type associated with the configured syntax 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 the 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.	Valid username.
new_name	Specifies the new name of the text search configuration.	A string compliant with the identifier naming rules.
new_schema	Specifies the new schema name of the text search configuration.	Valid schema name.
configuration_option	Specifies the text search configuration item.	For details, see CREATE TEXT SEARCH CONFIGURATION.
value	Specifies the value of text search configuration option.	-

Examples

Create a text search configuration named ngram1.

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

Add a mapping to the text search type ngram1.

     
          ALTER TEXT SEARCH CONFIGURATION ngram1 ADD MAPPING FOR multisymbol WITH simple;

Change the owner of text search configuration.

     
          CREATE USER joe password '{Password}';
ALTER TEXT SEARCH CONFIGURATION ngram1 OWNER TO joe;

Change the schema of text search configuration.

     
          ALTER TEXT SEARCH CONFIGURATION ngram1 SET SCHEMA joe;

Rename a text search configuration.

     
          ALTER TEXT SEARCH CONFIGURATION joe.ngram1 RENAME TO ngram_1;

Delete type mapping.

     
          ALTER TEXT SEARCH CONFIGURATION joe.ngram_1 DROP MAPPING IF EXISTS FOR multisymbol;

Create a text search configuration.

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

Add a mapping for the text search. (Convert regular words to lowercase and performs stemming.)

     
          ALTER TEXT SEARCH CONFIGURATION english_1 ADD MAPPING FOR word WITH simple,english_stem;

Add a mapping for the text search. (Stem email addresses in both English and French.)

     
          ALTER TEXT SEARCH CONFIGURATION english_1 ADD MAPPING FOR email WITH english_stem, french_stem;

Modify the mapping of the text search configuration.

     
          ALTER TEXT SEARCH CONFIGURATION english_1 ALTER MAPPING REPLACE french_stem with german_stem;

Query text search configurations.

     
          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;