The relationship between Oghma and Mystra—or rather, the Goddess of Magic—had always been very close. Long, long ago, after the Goddess of Magic was born, she studied under Oghma. After all, the concept of magic originated with Oghma, or rather, Oghma was the one who brought the concept of magic to Toril. Before Oghma came to Toril, there were only three living beings in all of Toril: the Lady of Night, Shar; the Lady of the Moon, Selune; and the Lady of the Earth, Chauntea. At the time, they had little concept of the world as a whole, so naturally they could not have possessed the concept of magic.
In that sense, Oghma could be considered the Goddess of Magic's teacher. Of course, this no longer had much to do with the current Mystra, since the Goddess of Magic was already in her third generation.
However, beginning with this generation of the Goddess of Magic, Oghma and Mystra had developed a slight rift. That rift stemmed from their differing philosophies.
The third Goddess of Magic did not have the close personal relationship with Oghma that the first generation had, nor did she share the second goddess's conservative beliefs. The direct cause of the second Goddess of Magic's birth had been the fall of Netheril. At that time, Karsus used the twelfth-circle arcanum, "Karsus's Avatar," to usurp the Goddess of Magic's authority, causing the Weave to spiral out of control and destroy all of Netheril.
After being reborn, the Goddess of Magic reconstructed the Weave and then sealed off the Inner Weave, restricting all spells beyond ninth-circle arcana. From that point onward, those immensely powerful arcana became legendary spells.
The second Goddess of Magic's attitude toward magic shifted from the first goddess's encouragement and promotion to restraint and caution.
This change