Guys, I am a Kannadiga and our weddings differ by caste. In the Brahmins it is a vow by fire i.e. Agnisakshi(witness of fire). The wedding muhuratha (t ime of the wedding)is set according to the bride and bridegrooms stars. There is Haldi ceremony in the previous day (boy's in the boy's home and girl in girl's home). In all Kannada weddings, Mangala sutra is tied with three knots(The design of the dollar or Mangalya is different among different castes) and is the main event of the wedding. After that there is Sapta padi or seven pheres. Before the Mangalya is tied to the girls neck by the boy, it is sent around the wedding hall and all present touch it (this is to say they are a witness and consent to the wedding). Reception is not so important and is only for the convenience of people.
In one community of Zamindars like the jats or patels or Gowdas etc. They wedding is not by agnisakshi(oath before fire) and it is witness of milk and water. Before the mangalya is tied, there is Kanya dhan(offering of the bride to the groom) and the bride's father makes the groom promise to be with the bride in sickness, in joy, in wealth and in poverty and all such thing(Dharmecha, arthecha nathicharami). After the Mangala sutra is tied, there are seven pheres. After this the bride and the groom are made to sit facing each other. They put their hands together and hold a coconut. A big vessel is put exactly under their hands. All present in the hall pour milk mixed with water over the hands of the bride and groom and throw scared rice over the heads of the bride and the groom(this is to bless the bride and groom and also like a sign off as a witness to the wedding). A lot od importance is given to rice, arecanut blossoms etc. The whole wedding takes place in a mantap built with cocomuts leaves.