http://debianws.lexgopc.com/wiki143/index.php?action=history&feed=atom&title=HHCodeHHCode - Revision history2026-10-26T04:13:43ZRevision history for this page on the wikiMediaWiki 1.43.1http://debianws.lexgopc.com/wiki143/index.php?title=HHCode&diff=5251678&oldid=previmported>GünniX: Reflist2025-02-16T18:40:53Z<p>Reflist</p>
<p><b>New page</b></p><div>{{Short description|Computer data storage format}}<br />
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A '''Helical Hyperspatial Code''', also known as an '''HHCode''', is a data storage format for very large spatio-temporal datasets.<br />
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The development of HHCode can be traced to efforts in the 1990's by [[Edric Keighan]], [[Panagiotis A. Vretanos]], [[Michael Galluchon]], and [[Herman P. Varma]] while working for the [[Canadian Hydrographic Service]]'s Atlantic regional offices at the [[Bedford Institute of Oceanography]] in [[Dartmouth, Nova Scotia|Dartmouth]], [[Nova Scotia]]. CHS was facing a problem with storing very large spatial datasets acquired during [[hydrographic survey]]s (thus having a temporal element) and was seeking a method to store the datasets in a [[relational database]] structure.<ref>[https://patents.justia.com/patent/6161105 US Patent 6161105], [[Oracle Corporation]], December 2000.</ref><br />
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CHS scientists reportedly conceptualized a spatio-temporal indexing system during a hydrographic survey onboard [[CCGS Hudson|CCGS ''Hudson'']] on [[Georges Bank]] during the summer of 1989. The indexing system involved an adaptation of a [[Riemann]]ian [[hypercube]] data structure, invoking a helical spiral through 3-dimensional space, which allowed for n-size of features.<br />
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The actual implementation of the proposed indexing system was termed a '''helical hyperspatial code''' and it was first used by modifying an installation of the [[Oracle database]] version 4. The HHCode indexing system permitted a highly efficient compression of not only spatial data but other data types as well, while improving search and retrieval times. The HHCode comprises a form of space filling curve and the concept was published by the CHS scientists in the ''[[International Hydrographic Review]]''.<br />
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[[Oracle Corporation]] subsequently learned of the innovation which led to an agreement with the Government of Canada which saw the CHS scientists working with a team of Oracle programmers at an office in [[Hull, Quebec]] during the early 1990s to redevelop the Oracle database [[kernel (operating system)|kernel]]. The resulting software was the Oracle database version 7, with the Spatial Data Option (SDO). Subsequent development of the SDO has resulted in the [[Oracle Spatial]] extension to current Oracle databases.<br />
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With the HHCode being an open-source data format, several spatial data and software companies have adopted it in various products targeted at very large corporate data users, namely Helical Systems Inc. and CubeWerx.<br />
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==References==<br />
{{Reflist}}<br />
* Varma, H. et al. ''A Data Structure for Spatio-Temporal Databases'' (1990). International Hydrographic Review, Monaco, LXVII(1), January.<br />
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[[Category:Science and technology in Canada]]<br />
[[Category:GIS file formats]]</div>imported>GünniX