Affirming this passage as literal at the expense of literalness of the 39 passages that teach that God does change his mind is arbitrary. God is not a man that He should change His mind. Analogy of a master at chess. Your eyes be held my unformed substance. In your book were written all the days that were formed for me, when none of them as yet existed.
Poetry calls for hermeneutical caution.
The Hebrew is very ambiguous. The phrase need not entail inalterability. Whatever problems this passages poses for the Open View, it poses for all Arminians. No one interpreted this passage in a Calvinistic fashion until Augustine. Socinius denied the Trinity, Deity of Christ and the atonement.