A method includes parsing a regular pathway expression into fragments including an anchored fragment and at least one other fragment. A number of the fragments is based on at least a length limitation of the regular pathway expression. The method includes generating an operator directed acyclic graph (DAG) including non-operator nodes, operator nodes, and a root based on at least the anchored fragment. The method includes removing, from the operator DAG, at least one of the non-operator nodes and connecting a first operator node to a second operator node of the operator nodes. The first operator node includes an edge into the at least one removed non-operator node, and the second operator node includes an edge from the at least one removed node. The method includes executing the operator DAG on a graph database to return a pathway set comprising at least one pathway that satisfies the regular pathway expression.