Perform full-text search with Data Connect

Firebase Data Connect supports full-text search, powered by PostgreSQL. Full-text search lets you quickly and efficiently locate information within large datasets by searching for keywords and phrases across multiple columns at once.

You can add full-text search to your service. First add the @searchable directive to the String in your schema that you want to search over. For example:

  type 
  
 Movie 
  
 @table 
  
 { 
  
 # The fields you want to search over 
  
 title 
 : 
  
 String 
 ! 
  
 @searchable 
  
 genre: 
  
 String 
  
 @searchable 
  
 description: 
  
 String 
  
 @searchable 
  
 tags: 
  
 [String] 
  
 # Some other fields that we won't search over 
  
 rating: 
  
 Float 
  
 imageUrl: 
  
 String! 
  
 releaseYear: 
  
 Int 
 } 
 

Once you add this directive, you can then perform full-text search by adding the <pluralType>_search field to a query. In this case, it'll be movies_search :

  query 
  
 SearchMovies 
 ( 
 $query 
 : 
  
 String 
 ) 
  
 @ 
 auth 
 ( 
 level 
 : 
  
 PUBLIC 
 ) 
  
 { 
  
 movies_search 
 ( 
 query 
 : 
  
 $query 
 ) 
  
 { 
  
 id 
  
 title 
  
 imageUrl 
  
 releaseYear 
  
 genre 
  
 rating 
  
 tags 
  
 description 
  
 } 
 } 
 

Fine-tuning full-text search results

You can fine-tune full-text search results by adding arguments to the @searchable directive and _search field;

Shared arguments

You can control search results with many of the same arguments used for basic list fields <pluralType> :

• order lets you change the order of results. If omitted, results will be ordered by descending relevance.
• where lets you add extra filters to search (e.g. search for only movies of a specific genre).
• limit makes the query only return the top X results.
• offset makes the query skip the first X results.
• distinct adds the DISTINCT operator to the generated SQL.

Language choice

By default, full-text search parses documents in English. You can change this with the language argument on the @searchable directive:

  type 
  
 Movie 
  
 @table 
  
 { 
  
 title 
 : 
  
 String 
 ! 
  
 @searchable 
 ( 
 language 
 : 
  
 "french" 
 ) 
  
 ... 
 } 
 

Specifying the right language will let PostgreSQL perform accurate lexical stemming and help make sure that your search does not miss relevant results. If you are searching over multiple columns, they must all be set to the same language.

Using psql , you can get the full list with the following query.

  SELECT 
  
 cfgname 
  
 FROM 
  
 pg_ts_config 
 ; 
 

Query format

By default, full-text search uses web semantics for queries (similar to Google search). You can change this behavior with the queryFormat argument on the <pluralType>_search field.

  query 
  
 SearchMovies 
 ( 
 $query 
 : 
  
 String 
 ) 
  
 @ 
 auth 
 ( 
 level 
 : 
  
 PUBLIC 
 ) 
  
 { 
  
 movies_search 
 ( 
 query 
 : 
  
 $query 
 , 
  
 queryFormat 
 : 
  
 PHRASE 
 ) 
  
 { 
  
 ... 
  
 } 
 } 
 

There are four options for query format:

• QUERYgives familiar semantics to web search engines (e.g. quoted strings, AND and OR). It is the default.
• PLAINmatches all of the words, but not necessarily together ("brown dog" will match " the brown and white dog" or "the white and brown dog").
• PHRASEmatches an exact phrase ( "brown dog" will match "the white and brown dog", but won't match "brown and white dog").
• ADVANCEDlets you create complex queries using the full set of tsquery operators .

Relevance threshold

Setting a relevance threshold means that your search will only return results above a certain relevance value. In many cases, you won't need to set this - any result that has a relevance greater than 0 will be a relevant result.

However, if you find that your search is returning results that don't feel relevant, relevance threshold can filter them out for you.

To figure out an appropriate value for relevance threshold, you should perform a few test searches and look at the _metadata.relevance :

  query 
  
 SearchMovies 
 ( 
 $query 
 : 
  
 String 
 ) 
  
 @ 
 auth 
 ( 
 level 
 : 
  
 PUBLIC 
 ) 
  
 { 
  
 movies_search 
 ( 
 query 
 : 
  
 $query 
 ) 
  
 { 
  
 id 
  
 title 
  
 _metadata 
  
 { 
  
 relevance 
  
 } 
  
 ... 
  
 } 
 } 
 

Choose a threshold that omits results that you feel are irrelevant. To do so:

  query 
  
 SearchMovies 
 ( 
 $query 
 : 
  
 String 
 ) 
  
 @ 
 auth 
 ( 
 level 
 : 
  
 PUBLIC 
 ) 
  
 { 
  
 movies_search 
 ( 
 query 
 : 
  
 $query 
 , 
  
 relevanceThreshold 
 : 
  
 0.05 
 ) 
  
 { 
  
 id 
  
 title 
  
 ... 
  
 } 
 } 
 

Choosing between full-text search, vector similarity search, and string pattern filters

Data Connect offers a few different ways to search over your database.

Use this table to help you choose the right one for your use case.