Computational resource requirements for each mapper dealing with real datasets. Random Access Memory (RAM, in gigabytes) consumption observed for each mapper, for the three real datasets (RD_100, RD_200 and RD_400) is shown. The values are the requirements for when the indexing and mapping steps were considered together. Vertical bars show the mean memory usage and vertical lines represent the peak memory usage. (1) indicates the mappers that report only one read (‘any-best’ mode) and (2) indicates the mappers that can run only in ‘all-best’ mode.