elasticsearchHow can I use Elasticsearch with PostgreSQL?
Elasticsearch can be used with PostgreSQL by creating a foreign data wrapper (FDW). A FDW is a PostgreSQL extension that allows for connecting to other data sources and querying them as if they were part of the PostgreSQL database.
This can be done by using the CREATE FOREIGN TABLE
command, which creates a table in PostgreSQL that is actually a link to a table in Elasticsearch.
Example code
CREATE SERVER elasticsearch_server FOREIGN DATA WRAPPER elastic_fdw OPTIONS (host 'localhost', port '9200');
CREATE USER MAPPING FOR postgres SERVER elasticsearch_server OPTIONS (username 'elastic', password 'mypassword');
CREATE FOREIGN TABLE my_table (
id int,
name text
) SERVER elasticsearch_server OPTIONS (index 'my_index', type 'my_type');
This code creates a server connection to Elasticsearch, a user mapping for PostgreSQL, and a foreign table that is linked to the Elasticsearch index and type.
Once the foreign table is created, it can be queried like any other table in PostgreSQL. For example, to get all documents in the foreign table:
SELECT * FROM my_table;
Output example
id | name
----+------
1 | John
2 | Jane
3 | Joe
Code explanation
CREATE SERVER
- creates a server connection to ElasticsearchCREATE USER MAPPING
- creates a user mapping for PostgreSQLCREATE FOREIGN TABLE
- creates a foreign table that is linked to the Elasticsearch index and typeSELECT * FROM my_table
- queries the foreign table
Helpful links
More of Elasticsearch
- How do I use an elasticsearch query builder?
- How can I use Elasticsearch and ZFS together?
- How can I use Yandex Mirror to access Elasticsearch data?
- How can I use Elasticsearch and Zookeeper together to manage distributed applications?
- How can I use Elasticsearch to diagnose "yellow" issues?
- How can I use Elasticsearch and Zabbix together for software development?
- How do I set up an Elasticsearch Yum repository?
- How can I use YouTube to learn about Elasticsearch?
- How can I use elasticsearch zone awareness to improve my software development?
- How do I configure elasticsearch to use an XMS memory allocator?
See more codes...