deepstream.io-storage-postgres

Postgres Database connector for deepstream.io

This connector is automatically installed when using the deepstream server > v5. It can also be installed via the deepstream command line interface via

deepstream install storage postgres

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

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 { Connector } = 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 Connector( 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/[email protected]

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' )