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
}
*/
})
})
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
npm i @deepstream/storage-postgres@2.0.1
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' )