On 1/16/24 11:20 AM, Ron Johnson wrote:
> Some RDBMSs have CREATE ALIAS, which allows you to refer to a table by a
> different name (while also referring to it by the original name).
>
> We have an application running on DB2/UDB which (for reasons wholly
> unknown to me, and probably also to the current developer) extensively
> uses this with two schemas: MTUSER and MTQRY. For example, sometimes
> refer to MTUSER.sometable and other times refer to it as MYQRY.sometable.
>
> My goal is to present a way to migrate from UDB to PG with as few
> application changes as possible. Thus, the need to mimic aliases.
>
> Maybe updatable views?
> CREATE VIEW mtqry.sometable AS SELECT * FROM mtuser.sometable;
Based on the schema names one possibility is that the aliases are there
as a pseudo-api between people/tools writing queries and the base
tables. IE: if you needed to make a (maybe backwards-incompatible)
change to "sometable" you now at least have the option of creating a
MTQRY.sometable *view* that hides whatever change you're making to
MTUSER.sometable.
In any case, yes, an updatable view would provide equivalent behavior in
Postgres.
--
Jim Nasby, Data Architect, Austin TX
