Re: Proposal for SYNONYMS

Jonah H. Harris wrote:
>
>
> This email is a preliminary design for the implementation of synonyms in
> PostgreSQL. Comments and suggestions are welcomed.
>
> BACKGROUND
>
> Synonyms are database objects which can be used in place of their
> referenced object in SELECT, INSERT, UPDATE, and DELETE SQL statements.
>
> There are two reasons to use synonyms which include:
>
> - Abstraction from changes made to the name or location of database objects
> - Alternative naming for another database object
>
> Similarly, RDBMS support for synonyms exists in Oracle, SQL Server, DB2,
> SAP DB/MAX DB, and Mimer.
>
> PROPOSED SQL ADDITIONS
>
> CREATE SYNONYM qualified_name FOR qualified_name
> DROP SYNONYM qualified_name
>
> In addition, SYNONYMS do participate in ACLs and support GRANT/REVOKE
> for table privileges. DROP TABLE and TRUNCATE cannot be used with synonyms.
>
> DESCRIPTION
>
> - A synonym can be created for a table, view, or synonym.
> - Synonyms can reference objects in any schema
>
> RESTRICTIONS
>
> - A synonym may only be created if the creator has some access privilege
> on the referenced object.
> - A synonym can only be created for an existing table, view or synonym.
> - A synonym name cannot be the same as the name of any other table, view
> or synonym which exists in the schema where the synonym is to be created.
>
> PROPOSED IMPLEMENTATION
>
> - Introduce a new relkind for synonyms
> - Synonyms only act as pointers to a real object by oid
> - Permission on a synonym does not override the permission on the
> referenced object
> - Referenced objects becomes dependencies of the synonyms that reference
> them
> - Synonyms follow PostgreSQL's current search_path behavior
>
> RUNTIME COST
>
> - Dependent on database user/administrator
> - In catalog searches which do not reference a synonym, the only cost
> incurred is that of searching the additional number of synonym objects
> in the catalog
> - In catalog searches which use a synonym, an additional cost is
> incurred to reference the real object
> - If no synonyms are created, no additional costs are incurred
>

hi jonah ...

the main problem i can see here is that it is strictly limited to
objects stored in pg_class.
however, support for stored procedures would be cool as well. what do
you suggest for those?

best regards,

hans

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