We study permuting and batched orthogonal geometric reporting problems in the External Memory Model (EM), assuming indivisibility of the input records. Our main results are twofold. First, we prove a general simulation result that essentially shows that any permutation algorithm (resp. duplicate removal algorithm) that does alpha*N/B I/Os (resp. to remove a fraction of the existing duplicates) can be simulated with an algorithm that does alpha phases where each phase reads and writes each element once, but using a factor alpha smaller block size. Second, we prove two lower bounds for batched rectangle stabbing and batched orthogonal range reporting queries. Assuming a short cache, we prove very high lower bounds that currently are not possible with the existing techniques under the tall cache assumption.
@InProceedings{afshani_et_al:LIPIcs.ESA.2017.2, author = {Afshani, Peyman and van Duijn, Ingo}, title = {{Permuting and Batched Geometric Lower Bounds in the I/O Model}}, booktitle = {25th Annual European Symposium on Algorithms (ESA 2017)}, pages = {2:1--2:13}, series = {Leibniz International Proceedings in Informatics (LIPIcs)}, ISBN = {978-3-95977-049-1}, ISSN = {1868-8969}, year = {2017}, volume = {87}, editor = {Pruhs, Kirk and Sohler, Christian}, publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik}, address = {Dagstuhl, Germany}, URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ESA.2017.2}, URN = {urn:nbn:de:0030-drops-78695}, doi = {10.4230/LIPIcs.ESA.2017.2}, annote = {Keywords: I/O Model, Batched Geometric Queries, Lower Bounds, Permuting} }
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