A Helical Hyperspatial Code, also known as an HHCode, is a data storage format for very large spatio-temporal datasets. 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 ''Retired Canadian Hydrographic Service logo or crest'' The Canadian Hydrographic Service (CHS) is part of the federal department of Fisheries and Oceans Canada and is Canada's authoritative hydrographic office. The CHS represents Canada in ...

's Atlantic regional offices at the Bedford Institute of Oceanography in Dartmouth,

Nova Scotia Nova Scotia is a Provinces and territories of Canada, province of Canada, located on its east coast. It is one of the three Maritime Canada, Maritime provinces and Population of Canada by province and territory, most populous province in Atlan ...

. CHS was facing a problem with storing very large spatial datasets acquired during

hydrographic survey Hydrographic survey is the science of measurement and description of features which affect maritime navigation, marine construction, dredging, offshore wind farms, offshore oil exploration and drilling and related activities. Surveys may als ...

s (thus having a temporal element) and was seeking a method to store the datasets in a

relational database A relational database (RDB) is a database based on the relational model of data, as proposed by E. F. Codd in 1970. A Relational Database Management System (RDBMS) is a type of database management system that stores data in a structured for ...

structure.US Patent 6161105

Oracle Corporation Oracle Corporation is an American Multinational corporation, multinational computer technology company headquartered in Austin, Texas. Co-founded in 1977 in Santa Clara, California, by Larry Ellison, who remains executive chairman, Oracle was ...

, December 2000. CHS scientists reportedly conceptualized a spatio-temporal indexing system during a hydrographic survey onboard CCGS ''Hudson'' on Georges Bank during the summer of 1989. The indexing system involved an adaptation of a

Riemann Georg Friedrich Bernhard Riemann (; ; 17September 182620July 1866) was a German mathematician who made profound contributions to analysis, number theory, and differential geometry. In the field of real analysis, he is mostly known for the first ...

ian

hypercube In geometry, a hypercube is an ''n''-dimensional analogue of a square ( ) and a cube ( ); the special case for is known as a ''tesseract''. It is a closed, compact, convex figure whose 1- skeleton consists of groups of opposite parallel l ...

data structure, invoking a helical spiral through 3-dimensional space, which allowed for n-size of features. 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 Oracle Database (commonly referred to as Oracle DBMS, Oracle Autonomous Database, or simply as Oracle) is a proprietary multi-model database management system produced and marketed by Oracle Corporation. It is a database commonly used for ru ...

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''.

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 Hull is the central business district and oldest neighbourhood of the city of Gatineau, Quebec, Canada. It is located on the west bank of the Gatineau River and the north shore of the Ottawa River, directly opposite Ottawa. As part of Canada's ...

during the early 1990s to redevelop the Oracle database

kernel Kernel may refer to: Computing * Kernel (operating system), the central component of most operating systems * Kernel (image processing), a matrix used for image convolution * Compute kernel, in GPGPU programming * Kernel method, in machine learnin ...

. 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 Oracle Spatial and Graph, formerly Oracle Spatial, is a free option component of the Oracle Database. The spatial features in Oracle Spatial and Graph aid users in managing geographic and location-data in a native type within an Oracle database, p ...

extension to current Oracle databases. 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.

References

{{Reflist * Varma, H. et al. ''A Data Structure for Spatio-Temporal Databases'' (1990). International Hydrographic Review, Monaco, LXVII(1), January. Science and technology in Canada GIS file formats