@deepstream/storage-postgres

deepstream.io-storage-postgres

Postgres Database connector for deepstream.io

This connector can be installed via the deepstream command line interface via

deepstream install storage postgres

and can be configured in the plugins storage section of deepstreams config.yml. Supported options are

plugins:
  storage:
    name: postgres
    options:
      user: some-user
      database: some-database
      password: some-password
      host: localhost
      port: 5432 #postgres default post
      schema: ds #schema defaults to ds. Will be created if it doesn't exist
      defaultTable: default # default table name defaults to default
      max: 10 #concurrent connections
      idleTimeoutMillis: 30000 #timeout after which connection will be cut
      writeInterval: 200 #amount of milliseconds during which writes will be buffered
      useJsonb: false #store values as searchable binary JSON (slower)
      notifications:
        CREATE_TABLE: false #Get notified when tables are created
        DESTROY_TABLE: false #Get notified when tables are dropped
        INSERT: false # Get notified when records are created
        UPDATE: false # Get notified when records are updated
        DELETE: false # Get notified when records are deleted

This connector can also be used as a standalone component from node.js to connect to postgres' notification mechanism. To do this, install the connector via

npm install @deepstream/storage-postgres

and instantiate it directly

const PostgresConnector = require( '@deepstream/storage-postgres' );
const settings = {
  user: process.env.PG_USER,
  database: process.env.PG_DB,
  password: process.env.PG_PASSWORD,
  host: process.env.PG_HOST,
  port: parseInt( process.env.PG_PORT, 10 )
}

const connector = new PostgresConnector( settings )

// start connector
connector.init()

connector.on( 'ready', ()=>{
    connector.subscribe( event =>{
        //event will be a map of event and table for CREATE_TABLE and DESTROY_TABLE
        // { event: 'CREATE_TABLE', table: 'some-table' })
        // or of event, table and key for INSERT, UPDATE AND DELETE, e.g.
        // { event: 'INSERT', table: 'some-table', key: 'some-key' }
    }, err => { if( err ) throw err; })

    //subscriptions can be removed
    connector.unsubscribe(( err )=>{ /* done */ })

    // the connector also comes with a facility to get a map of all tables and the numbers of items within
    connector.getSchemaOverview(( err, result ) => {
        /* result will be e.g.
        {
            'some-table': 2,
            'some-other-table': 1,
            'new-table': 1,
            'table-a': 2,
            'table-b': 2
        }
        */
    })
})

Migrating to the latest connector version

The latest connector version (3.x) introduces breaking changes at database level for a cleaner data structure: one column for id, one for version, one for value.

For migrating a current database from the v2 connector to v3 check out this script

Installing the previous connector version

npm i @deepstream/storage-postgres@2.0.1

Deepstream v3 users

For user of the deepstream server version 3.x, install the connector with npm install deepstreamIO/deepstream.io-storage-postgres#v1.1.5.

Require as require( 'deepstream.io-storage-postgres' )