1. A computer-implemented method, comprising: receiving a transaction comprising a plurality of operations, the transaction applicable to a graph database; representing the transaction by a transaction graph, the transaction graph being a dependency graph representing dependencies among the plurality of operations of the transaction; partitioning, by a computer processor, the transaction graph into two or more transaction subgraphs, each of the two or more transaction subgraphs comprising two or more operations of the transaction, each of the two or more transaction subgraphs being a dependency graph representing dependencies among the two or more operations of the transaction subgraph, and the two or more transaction subgraphs being independent of one another; wherein the partitioning the transaction graph into two or more transaction subgraphs comprises: partitioning the transaction graph into two or more intermediate transaction subgraphs; identifying one or more crossover edges crossing between a first intermediate transaction subgraph and a second intermediate transaction subgraph, the first and second intermediate transaction subgraphs being distinct and belonging to the two or more intermediate transaction subgraphs; extracting from the first and second intermediate transaction subgraphs each vertex at which at least one of the one or more crossover edges terminates; and inserting each extracted vertex into a residual subgraph; and applying the two or more transaction subgraphs to the graph database in parallel, wherein applying each transaction subgraph to the graph database comprises applying the two or more operations of the transaction subgraph to the graph database.