Proof of concept mini project which shows combined PostgreSQL 9.6 features (full text search and trigrams) to mimic some Google-like search capabilities typically achievable with Elasticsearch.

Implemented as a bunch of Clojure functions which allow to:

• connect to PostgreSQL,
• create database schema (tables and triggers),
• populate database with random data,
• perform search.

Usage

1. Install Java 8.

2. Install Leiningen.

3. Create PostgreSQL database and user which is owner of it. The database needs to have pg_trgm extension.

CREATE EXTENSION pg_trgm;

4. Clone this repository.

5. Edit file /resources/config.edn to set:

• database name,
• database host,
• database port,
• database user,
• database password.

6. cd to cloned repository and execute:

lein repl

The output should be:

nREPL server started on port 35213 on host 127.0.0.1 - nrepl://127.0.0.1:35213
REPL-y 0.3.7, nREPL 0.2.12
Clojure 1.8.0
Java HotSpot(TM) 64-Bit Server VM 1.8.0_111-b14
    Docs: (doc function-name-here)
          (find-doc "part-of-name-here")
  Source: (source function-name-here)
 Javadoc: (javadoc java-object-or-class-here)
    Exit: Control+D or (exit) or (quit)
 Results: Stored in vars *1, *2, *3, an exception in *e

 try-postgres-fuzzy-search.core=>

7. Create database schema with:

(create-schema!)

8. Connect to database with:

(connect!)

9. Populate database with one million persons with:

(insert-persons! 1000000)

10. Get random data from database.

(pprint (get-random-persons 5))

The example output:

({:id 17820, :first_name "Barney", :last_name "Gislason"}
 {:id 17821, :first_name "Destiny", :last_name "Rogahn"}
 {:id 17822, :first_name "Allison", :last_name "Altenwerth"}
 {:id 17823, :first_name "Willie", :last_name "Rippin"}
 {:id 17824, :first_name "Pink", :last_name "Crona"})
nil

11. Perform search:

• search without typos:

  (pprint (search-person "Barney" "Gislason"))

• search with typos and with beginning of word:

  (pprint (search-person "Berney" "Gisl"))

• search by only one word (with typo):

  (pprint (search-person "Gisleson"))

12. Disconnect from database.

(disconnect!)

13. (Optionally) Drop database schema.

(drop-schema!)

14. Exit REPL.

exit

License

Eclipse Public License version 1.0.