1. A computer implemented method for improving a query, comprising: generating a subplan; determining similarity between a hypergraph of the subplan and a hypergraph of an etalon query with known properties by calculating a similarity measure, the similarity measure indicating similarity between a number of connected subgraphs of a subplan hypergraph and an etalon query hypergraph, the hypergraph of the subplan comprising a vertex corresponding to a quantifier of the subplan; predicting one or more properties of an algorithm available for improving the subplan based on the similarity measure; selecting an algorithm from a plurality of algorithms available for improving the subplan; generating an improved access plan using the selected algorithm; and storing a degree sequence used for calculating the similarity measure and a set of statistics for each algorithm of the plurality of algorithms as properties of one or more etalon queries.