What is a mutating table or mutating trigger?

Question

Accepted Answer

A mutating table or mutating trigger occurs when a trigger tries to update a table that is currently being modified.

Mutating table occurs when a trigger references the table that is being modified.
It can happen when a trigger is fired by an INSERT, UPDATE, or DELETE statement on the table.
This can lead to unpredictable results or errors, such as ORA-04091: table is mutating, trigger/function may not see it.
To avoid mutating table errors, use row-level triggers instead of statement-level triggers.
Another approach is to use compound triggers, which allow you to define multiple trigger timing points within a single trigger.
Here's an example: If a trigger updates a row in table A, and the trigger itself is fired by an update on table A, it will cause a mutating table error.

Accepted Answer

A mutating table error happens when a row-level trigger tries to access the same table that triggered it, either directly or indirectly.

Accepted Answer

When we try to do DML or select from a table in a trigger which actually fired the trigger, then we get mutating table error. This error we get only in row level trigger.

Accepted Answer

Mutation table is a that is changing but in dealing with triggers it is a table that the possibility of changing.This does not impact the exclusive use of OLD and NEW

Accepted Answer

When we will try to perform any dml operation in trigger then muttaing error will be fired in that mutatting table.

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What is a mutating table or mutating trigger?

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