![]() Words in the query should match variants (such as suffixes) of that word in the document, e.g.Users enter search terms that will be converted into queries against the database, and the results are displayed back to the user. ![]() To explore some of these limitations, let’s look at some typical requirements for a comprehensive search feature of an application/website: They have no ability to rank results based on relevance to the query, and, critically, they can be slow due to limited indexing support. These operators lack linguistic support-such as understanding the structure of text (including punctuation), recognizing word variants and synonyms, and ignoring frequently used words. While it is possible to use these operators to perform very basic searches, pattern matching has several limitations that make it less than ideal for implementing useful searches. The text datatype has several operators for performing basic string pattern matching, notably LIKE/ ILIKE (SQL wildcard matches, case sensitive and insensitive, respectively), SIMILAR TO (SQL regex) and ~ (POSIX regex). For example, usernames, passwords, and URLs are often human-readable, but don’t typically contain natural language. Note that not all human-readable strings contain natural language. These types of documents are typical candidates for full-text search indexing. Some examples of natural language text are blog posts (such as the one you’re reading now), books, essays, user comments, forum posts, social media messages, emails, newsgroup and chat messages, newspaper and magazine articles, and product descriptions in a catalog.
0 Comments
Leave a Reply. |