In this paper, we completely characterize the compactness of the Volterra type integration operators J b acting from weighted Bergman spaces A p α to Hardy spaces H q for all 0 < p, q < ∞. Furthermore, we give some estimates for the essential norms of J b : A p α → H q in the case 0 < p ≤ q < ∞. We finally describe the membership in the Schatten(-Herz) class of the Volterra type integration operators.