Abstract: A bit vector having a bit vector length is accessed. A select operator directory tree can be generated using the bit vector. The select operator directory tree includes a first level of superblocks including large superblocks and small superblocks, a second level of blocks including large blocks and small blocks, each block associated with one of the superblocks, and a third level of sub-blocks, each sub-block associated with a block. The large superblocks each have, a length greater than a first constant that is independent of the bit vector length and the large blocks each have a length greater than a second constant that is independent of the bit vector length. The select operator directory tree can be stored. Related apparatus, systems, techniques and articles are also described.

Abstract: A plus-minus-one array in which adjacent entries vary by no more than positive one and no less than negative one is accessed. A range minimum query directory tree including blocks and subblocks of the plus-minus-one array is determined. Blocks are contained in the plus-minus-one array and subblocks are contained in the blocks. A data structure characterizing positions of minimum elements within the range minimum query directory tree is generated. The characterization includes positions of minimums within each subblock, between subblocks in a respective block, within each block, and between blocks. The data structure is stored. Related apparatus, systems, techniques and articles are also described.

Abstract: A plus-minus-one array in which adjacent entries vary by no more than positive one and no less than negative one is accessed. A range minimum query directory tree including blocks and subblocks of the plus-minus-one array is determined. Blocks are contained in the plus-minus-one array and subblocks are contained in the blocks. A data structure characterizing positions of minimum elements within the range minimum query-directory tree is generated. The characterization includes positions of minimums within each subblock, between subblocks in a respective block, within each block, and between blocks. The data structure is stored. Related apparatus, systems, techniques and articles are also described.

Abstract: A bit vector having a bit vector length is accessed. A select operator directory tree can be generated using the bit vector. The select operator directory tree includes a first level of superblocks including large superblocks and small superblocks, a second level of blocks including large blocks and small blocks, each block associated with one of the superblocks, and a third level of sub-blocks, each sub-block associated with a block. The large superblocks each have, a length greater than a first constant that is independent of the bit vector length and the large blocks each have a length greater than a second constant that is independent of the bit vector length. The select operator directory tree can be stored. Related apparatus, systems, techniques and articles are also described.