Re: Composite types for updatable views

Hi ,
        Yes, i  agree with the statement below , a column is updatable if it is a simple reference to an updatable column of the underlying base relation . View updatability for composite types (being derived construct) will pose challenges

Possible temporary work around is:


  1.
Avoid composite types in views and use individual columns from base table
  2.
using a trigger function to update the view for some use cases


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While simple views are automatically updatable [1], this does not extend to composite types; that is, if a view constructs a composite type for one or more columns, this column then is not updatable:

> A column is updatable if it is a simple reference to an updatable column of the underlying base relation

It would seem simple enough to support composite types if the view column is constructed using row expression in which each field is "a simple reference to an updatable column".

As a practical example, this could enable geometric types being exposed at the view layer, but supported in an underlying table by primitive types.

[1] https://www.postgresql.org/docs/current/sql-createview.html#SQL-CREATEVIEW-UPDATABLE-VIEWS



Thanks

Dinesh Nair


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From: Malthe <mborch@gmail.com>
Sent: Wednesday, July 16, 2025 5:36 PM
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Subject: Composite types for updatable views

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While simple views are automatically updatable [1], this does not extend to composite types; that is, if a view constructs a composite type for one or more columns, this column then is not updatable:

> A column is updatable if it is a simple reference to an updatable column of the underlying base relation

It would seem simple enough to support composite types if the view column is constructed using row expression in which each field is "a simple reference to an updatable column".

As a practical example, this could enable geometric types being exposed at the view layer, but supported in an underlying table by primitive types.

[1] https://www.postgresql.org/docs/current/sql-createview.html#SQL-CREATEVIEW-UPDATABLE-VIEWS