표 9.41, 표 9.42 and 표 9.43 summarize the functions and operators that are provided for full text searching. See 12장 for a detailed explanation of PostgreSQL's text search facility.
표 9.41. Text Search Operators
Operator Description Example(s) |
|---|
Does
|
Does text string, after implicit invocation
of
|
This is a deprecated synonym for
|
Concatenates two
|
ANDs two
|
ORs two
|
Negates a
|
Constructs a phrase query, which matches if the two input queries match at successive lexemes.
|
Does first
|
Is first
|
In addition to these specialized operators, the usual comparison
operators shown in 표 9.1 are
available for types tsvector and tsquery.
These are not very
useful for text searching but allow, for example, unique indexes to be
built on columns of these types.
표 9.42. Text Search Functions
Function Description Example(s) |
|---|
Converts an array of lexemes to a
|
Returns the OID of the current default text search configuration (as set by default_text_search_config).
|
|
Returns the number of lexemes in the
|
|
Returns the number of lexemes plus operators in
the
|
Converts text to a
|
Converts text to a
|
Converts text to a
|
|
Produces a representation of the indexable portion of
a
|
Assigns the specified
|
Assigns the specified
|
|
Removes positions and weights from the
|
Converts text to a
|
Converts text to a
|
Converts each string value in the JSON document to
a
|
Selects each item in the JSON document that is requested by
the
|
Removes any occurrence of the given
|
Removes any occurrences of the lexemes
in
|
Selects only elements with the given
|
Displays, in an abbreviated form, the match(es) for
the
|
Displays, in an abbreviated form, match(es) for
the
|
Computes a score showing how well
the
|
Computes a score showing how well
the
|
Replaces occurrences of
|
Replaces portions of the
|
Constructs a phrase query that searches
for matches of
|
Constructs a phrase query that searches
for matches of
|
Converts a
|
Expands a
lexeme | positions | weights
--------+-----------+---------
cat | {3} | {D}
fat | {2,4} | {D,D}
rat | {5} | {A}
|
All the text search functions that accept an optional regconfig
argument will use the configuration specified by
default_text_search_config
when that argument is omitted.
The functions in 표 9.43 are listed separately because they are not usually used in everyday text searching operations. They are primarily helpful for development and debugging of new text search configurations.
표 9.43. Text Search Debugging Functions
Function Description Example(s) |
|---|
Extracts and normalizes tokens from
the
|
Returns an array of replacement lexemes if the input token is known to the dictionary, or an empty array if the token is known to the dictionary but it is a stop word, or NULL if it is not a known word. See 12.8.3절 for details.
|
Extracts tokens from the
|
Extracts tokens from the
|
Returns a table that describes each type of token the named parser can recognize. See 12.8.2절 for details.
|
Returns a table that describes each type of token a parser specified by OID can recognize. See 12.8.2절 for details.
|
Executes the
|