Change request ID start number

Change request ID start number

Hello, my version is: 10.5 Construir 10506.
I'm trying to change the incidence number.

I used to use:

1. For PGSQL database : connect to the database following the below steps and then execute the queries.
2. Open command prompt on the application server,connect to the folder ManageEngine\ServiceDesk\pgsql\bin and use the command psql.exe -U postgres -p 65432 -d servicedesk
But I run it and ever if I restart the service ir doesn't tun ti as before.
Could someone tell me why? 
Thank you very much in advance.
I'm sorry for my English.