Added docs for knex pool config

Signed-off-by: sharadpattanshetti <43475650+sharadpattanshetti@users.noreply.github.com>

docs/tutorials/switching-sqlite-postgres.md

@@ -55,3 +55,35 @@ launching Backstage, or remove the `${...}` values and simply set actual values
 directly for development.
 
 The Backstage App is now ready to start up with a PostgreSQL backing database.
+
+### Override default PostgreSQL Database Pool Configuration
+
+If you want to override the default connection pool settings then use the below configuration:
+
+```diff
+backend:
+  database:
+-    client: better-sqlite3
+-    connection: ':memory:'
++    # config options: https://node-postgres.com/api/client
++    client: pg
++    connection:
++      host: ${POSTGRES_HOST}
++      port: ${POSTGRES_PORT}
++      user: ${POSTGRES_USER}
++      password: ${POSTGRES_PASSWORD}
++    # Refer to Tarn docs for default values on PostgreSQL pool configuration - https://github.com/Vincit/tarn.js
++    knexConfig:
++      pool:
++        min: 3
++        max: 12
++        acquireTimeoutMillis: 60000
++        idleTimeoutMillis: 60000
++      # https://node-postgres.com/features/ssl
++      # you can set the sslmode configuration option via the `PGSSLMODE` environment variable
++      # see https://www.postgresql.org/docs/current/libpq-ssl.html Table 33.1. SSL Mode Descriptions (e.g. require)
++      # ssl:
++      #   ca: # if you have a CA file and want to verify it you can uncomment this section
++      #     $file: <file-path>/ca/server.crt   
+```
+