What is mutating table?

Answer Posted / kaushik

A mutating table is a table that is currently being modified
by an UPDATE, INSERT or DELETE statement, or a table that
might need to be updated by the effects of a declarative
DELETE CASCADE referential integrity action. A table is not
considered mutating for STATEMENT triggers.

The triggered table itself is a mutating table as well as
any table referencing it with the foreign key constraint.
This restriction prevents a row trigger from seeing an
inconsistent set of data.

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