What is the ruling on a prayer performed between sleep and wakefulness, and must it be repeated after fully waking up?

If you know that you have performed the pillars and obligatory acts of prayer, both actions and recitations, then your prayer is valid and you are not required to repeat it. However, if you do not know this, then your prayer is invalid and you must repeat it. This applies to both obligatory (fard) and supererogatory (nafl) prayers. Mild drowsiness that does not affect the performance of the obligatory acts does not invalidate the prayer. However, drowsiness that causes the worshipper to be unaware of what obligatory acts they have performed renders their prayer invalid and requires them to repeat it.