![]() ![]() 567 rows = 0 loops= 1 )ġ2 Workers Planned: 1 13 Workers Launched: 1 14 -> Parallel Seq Scan on document ( cost = 0.00. documentĦ WHERE to_tsvector( 'english', text ) to_tsquery( 'english', 'fielded & window & lamp & depth & test ' )ĩ - 10 Limit ( cost = 1000.00. document USING gin (to_tsvector( 'english' :: regconfig, text )) WHERE language = 'en' Ģ CREATED INDEX 3 > EXPLAIN ANALYZE 4 SELECT text, language 5 FROM public. ![]() Tsearch full-text search with stored partial indexĪ partial index gives a possibility to store records in different languages using the same database table and query them effectively.ġ > CREATE INDEX ix_en_document_tsvector_text ON public. However, our data have not been indexed yet. 349 rows = 0 loops= 1 )ġ0 Workers Planned: 1 11 Workers Launched: 1 12 -> Parallel Seq Scan on document ( cost = 0.00. There also must be created a configuration (see docs) inside database:Ĥ WHERE to_tsvector( 'english', text ) to_tsquery( 'english', 'fielded & window & lamp & depth & test ' )ħ - 8 Limit ( cost = 1000.00. ![]() To determine your sharedir location you can use pg_config -sharedir. Polish.affix, polish.stop and polish.dict files should be copied to PostgreSQL sharedir tsearch_data location,Į.g. Polish dictionary files can be downloaded from. Here is an example for the polish language. You just need additional dictionary files. However, you can set up the configuration quite easily. Postgres tsearch does not provide support for many languages by default. Create non-default language configuration for tsearch full-text search So, when you would like to perform a search based on canonical forms of words, you should choose tsearch engine. However, this approach is generic and does not exploit the morphological distinction of a language. Ilike with trigrams can be enough solution for many projects. 471 rows = 0 loops= 1 )ġ8 Recheck Cond: (( text ~~* '%field%' :: text ) AND ( text ~~* '%window%' :: text ) AND ( text ~~* '%lamp%' :: text ) AND ( text ~~* '%research%' :: text ) AND (( language ):: text = 'en' :: text ))ġ9 -> Bitmap Index Scan on ix_document_text_trigram ( cost = 0.00. 474 rows = 0 loops= 1 )ġ7 -> Bitmap Heap Scan on document ( cost = 176.00. documentħ WHERE 8 text ilike '%field%' 9 AND text ilike '%window%' 10 AND text ilike '%lamp%' 11 AND text ilike '%research%' 12 AND language = 'en' 13 LIMIT 1 ġ5 - 16 Limit ( cost = 176.00. See the trigram example:ġ > CREATE INDEX ix_document_text_trigram ON document USING gin ( text gin_trgm_ops) where language = 'en' Ģ CREATE INDEX 3 4 > EXPLAIN ANALYZE 5 SELECT text, language 6 FROM public. ![]() What is a trigram search? Citing wikipedia: It finds objects which match the maximum number of three-character strings in the entered search terms. However, we can improve ilike performance using trigram search. 466 rows = 0 loops= 1 )ġ5 Filter : (( text ~~* '%field%' :: text ) AND ( text ~~* '%window%' :: text ) AND ( text ~~* '%lamp%' :: text ) AND ( text ~~* '%research%' :: text ))ġ6 Rows Removed by Filter : 100001 17 Planning Time : 2.193 msġ9 Full-text search using ilike supported by trigram index 474 rows = 0 loops= 1 )ġ4 -> Seq Scan on document ( cost = 0.00. documentĤ WHERE 5 text ilike '%field%' 6 AND text ilike '%window%' 7 AND text ilike '%lamp%' 8 AND text ilike '%research%' 9 AND language = 'en' 10 LIMIT 1 ġ2 - 13 Limit ( cost = 0.00. 1 > EXPLAIN ANALYZE 2 SELECT text, language 3 FROM public. ![]()
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