Delete trigger and data integrity

Hello everyone,

I have this question regarding delete triggers and how it affects data
integrity.

So here goes: I have this trigger which deletes everything before I insert
new rows.

CREATE OR REPLACE FUNCTION delete_records()

RETURNS TRIGGER AS $$

BEGIN

delete from "TABLE";

RETURN NEW;

END;

$$

LANGUAGE plpgsql;

CREATE TRIGGER delete_on_insert

BEFORE INSERT ON "TABLE"

FOR EACH ROW EXECUTE PROCEDURE delete_records();

My question is what happens while this function is executed? Is there any
chance the table can return empty data between the delete and insert
commands? Or does a trigger like this block this possibility somehow?

Thank you

Kind regards,
*Yvonne Zannoun*

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