Recently I've found a piece of code for ruby on rails which should search string like like-operator:
scope :search, -> (query) { where('name @@ :q', q: query) }
But couldn't find any documentation about it.
The operator doesn't work as expected. So what exactly it does?
It's a text search, check out documentation.
If you'd rather not go somewhere else for an answer, here:
The @@ operator in PostgreSQL is related to the full-text search capabilities provided by the tsquery and tsvector types. The @@ operator is used to compare a tsquery value (the query) with a tsvector value (the document) to determine if the document matches the query.
The tsvector type represents a document processed for full-text search, while the tsquery type represents a query in a format suitable for searching in tsvector documents. The @@ operator returns true if the query matches the document, and false otherwise.