Setting an alias for a record isn’t mandatory in Unidatab but it can make a database available for multi-user and online use. Just as much as a type policy is needed for the sake of inner soundness of a database, an alias policy is needed in order to combine several databases over the network, making records usable to users who can’t know their local IDs. Many of the unidSql functions accept aliases strings as arguments.
But unlike types, aliases can be set in a multiple way, i.e. one record can have several aliases. Thus we can define several sets of aliases that are synonyms – or contextual – for the same records.