In the Rig Veda, there are nearly five hymns that are
dedicated to Hindu God Vishnu. He is also part of some other hymns. In all the
Vedas put together his name only appears about 100 times.
Macdonell in his Vedic Mythology states:
He thrice traversed the earthly spaces for man in distress, he traversed the earth to bestow it on man for a dwelling, he traversed the earthly spaces for wide-stepping existence, with Indra he took wide strides and stretched out the worlds for our existence.In Rig Veda, Vishnu is subservient to Indra.
However, there is a change in the status and by later Vedic period;
Vishnu had become the greatest god. During later Vedic period, Vishnu is beneficent,
innocuous, and bountiful, liberal and generous deliverer and alone sustains the
threefold world – heaven, earth and all beings.
In the Rig Veda, Vishnu is called Gopa, the herdsman. The specific
term used is Vishnurgopa (Rig Veda 1.22.18). He is also referred as Govinda,
the cow keeper and Damodara – one with the cord around one’s belly.
In Vedas, he also equated with Yajna. He is referred as
Yajna, Yajnapurusha and Yajnavahana. He averts all the evil consequences that
arises out of Yajna or sacrifice.
During the later Vedic period, numerous deities and their cults
go assimilated in Vishnu.
Thus during the beginning of the Vedic period Vishnu was a
minor deity but by the end of the Vedic era, Vishnu had become the most
powerful deity.