openGauss每日一练第20天-全文检索

omm=# SELECT 'The Fat Rats'::tsvector;
(1 row)

omm=# tsvector
--------------------
'Fat' 'Rats' 'The'
omm=#
SELECT 'a:1 fat:2 cat:3 sat:4 on:5 a:6 mat:7 and:8 ate:9 a:10 fat:11 rat:12'::tsvector;
'a':1,6,10 'and':8 'ate':9 'cat':3 'fat':2,11 'mat':7 'on':5 'rat':12 'sat':4
(1 row)

omm=# tsvector
-------------------------------------------------------------------------------

omm=# SELECT 'a:1A fat:2B,4C cat:5D'::tsvector;
tsvector
----------------------------
'a':1A 'cat':5 'fat':2B,4C
(1 row)

omm=# SELECT to_tsvector('english', 'The Fat Rats');


omm=# to_tsvector
-----------------
'fat':2 'rat':3
(1 row)SELECT 'fat & rat'::tsquery;
tsquery
---------------
'fat' & 'rat'
(1 row)

omm=# SELECT to_tsquery('Fat:ab & Cats');
to_tsquery
------------------
'fat':AB & 'cat'
(1 row)

omm=# SELECT 'a fat cat sat on a mat and ate a fat rat'::tsvector @@ 'cat & rat'::tsquery AS RESULT;
result
--------
t
(1 row)

omm=# SELECT 'fat & cow'::tsquery @@ 'a fat cat sat on a mat and ate a fat rat'::tsvector AS RESULT;
result
--------
f
(1 row)

omm=# SELECT to_tsvector('fat cats ate fat rats') @@ to_tsquery('fat & rat') AS RESULT;
result
--------
t
(1 row)

omm=# SELECT to_tsvector('fat cats ate fat rats') @@ to_tsquery('fat & cow') AS RESULT;
result
--------
f
(1 row)

omm=# \dF
List of text search configurations
Schema | Name | Description
pg_catalog | dutch | configuration for dutch language
pg_catalog | english | configuration for english language
pg_catalog | finnish | configuration for finnish language
pg_catalog | french | configuration for french language
pg_catalog | german | configuration for german language
pg_catalog | hungarian | configuration for hungarian language
------------+------------+---------------------------------------
pg_catalog | danish | configuration for danish language
pg_catalog | norwegian | configuration for norwegian language
pg_catalog | portuguese | configuration for portuguese language
pg_catalog | pound | pound configuration
pg_catalog | romanian | configuration for romanian language
pg_catalog | italian | configuration for italian language
pg_catalog | ngram | ngram configuration
pg_catalog | spanish | configuration for spanish language
pg_catalog | swedish | configuration for swedish language
pg_catalog | russian | configuration for russian language
pg_catalog | simple | simple configuration
pg_catalog | turkish | configuration for turkish language
pg_catalog | zhparser | zhparser configuration
(19 rows)

omm=# show default_text_search_config;

(1 row)

omm=# default_text_search_config
----------------------------
pg_catalog.englishomm=#
omm=#
CREATE SCHEMA tsearch;
CREATE SCHEMA
omm=# CREATE TABLE tsearch.pgweb(id int, body text, title text, last_mod_date date);
CREATE TABLE
omm=# INSERT INTO tsearch.pgweb VALUES(1, 'China, officially the People''s Republic of China(PRC), located in Asia, is the world''s most populous state.', 'China', '2010-1-1');
INSERT 0 1
omm=# INSERT INTO tsearch.pgweb VALUES(2, 'America is a rock band, formed in England in 1970 by multi-instrumentalists Dewey Bunnell, Dan Peek, and Gerry Beckley.', 'America', '2010-1-1');
INSERT 0 1
omm=# INSERT INTO tsearch.pgweb VALUES(3, 'England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west.', 'England','2010-1-1');
INSERT 0 1
omm=# SELECT id, body, title FROM tsearch.pgweb WHERE to_tsvector(body) @@ to_tsquery('america');
id | body |
title
----+-------------------------------------------------------------------------------------------------------------------------+
---------
2 | America is a rock band, formed in England in 1970 by multi-instrumentalists Dewey Bunnell, Dan Peek, and Gerry Beckley. |
America
(1 row)

omm=# SELECT title FROM tsearch.pgweb WHERE to_tsvector(title || ' ' || body) @@ to_tsquery('china & asia');
title
-------
China
(1 row)

omm=# CREATE INDEX pgweb_idx_1 ON tsearch.pgweb USING gin(to_tsvector('english', body));
CREATE INDEX
omm=# CREATE INDEX pgweb_idx_3 ON tsearch.pgweb USING gin(to_tsvector('english', title || ' ' ||
omm(# body));
CREATE INDEX
omm=# \d+ tsearch.pgweb
Table "tsearch.pgweb"
Column | Type | Modifiers | Storage | Stats target | Description
---------------+---------+-----------+----------+--------------+-------------
id | integer | | plain | |
body | text | | extended | |
title | text | | extended | |
last_mod_date | date | | plain | |
Indexes:
"pgweb_idx_1" gin (to_tsvector('english'::regconfig, body)) TABLESPACE pg_default
"pgweb_idx_3" gin (to_tsvector('english'::regconfig, (title || ' '::text) || body)) TABLESPACE pg_default
Has OIDs: no
omm=# Options: orientation=row, compression=no


omm=# drop schema tsearch cascade;
NOTICE: drop cascades to table tsearch.pgweb
DROP SCHEMA
omm=#
omm=#
omm=#