You grant the user privileges. The user you want to grant permissions must have a valid unix account on the server.
To allow a user to connect to database. As owner or dba of the database issue:
Where is the name of the database. is the user who requires ability to connect.
To allow user to run queries on specific tables. As owner of the table or as dba user issue:
NOTE: If the table has PUBLIC privileges, the second step is not necessary. (dbschema will show)
NOTE: Other abilities such as insert, delete, update can be added in the same manner as the second step. Substitute "select" with desired action.
dbschema -d -t -ss