HHCode
Encyclopedia
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 by scientists working for the Canadian Hydrographic Service
's Atlantic regional offices at the Bedford Institute of Oceanography
in 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.
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 Riemannian hypercube
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
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.
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
. 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.
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.
The development of HHCode can be traced to efforts by scientists working for the Canadian Hydrographic Service
Canadian Hydrographic Service
The Canadian Hydrographic Service is Canada's hydrographic office, with responsibility for performing hydrographic surveys and publishing paper and electronic nautical charts...
's Atlantic regional offices at the Bedford Institute of Oceanography
Bedford Institute of Oceanography
The Bedford Institute of Oceanography is a major Canadian government ocean research facility located in Dartmouth in the Halifax Regional Municipality in Nova Scotia. The Bedford Institute of Oceanography is the largest ocean research station in Canada...
in Dartmouth
Dartmouth, Nova Scotia
Dartmouth founded in 1750, is a community and planning area of the Halifax Regional Municipality, Nova Scotia. Located on the eastern shore of Halifax Harbour, Dartmouth has been nicknamed the City of Lakes after the large number of lakes located in the city.On April 1, 1996, the provincial...
, Nova Scotia
Nova Scotia
Nova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...
. CHS was facing a problem with storing very large spatial datasets acquired during hydrographic survey
Hydrographic survey
Hydrographic survey is the science of measurement and description of features which affect maritime navigation, marine construction, dredging, offshore oil exploration/drilling and related disciplines. Strong emphasis is placed on soundings, shorelines, tides, currents, sea floor and submerged...
s (thus having a temporal element) and was seeking a method to store the datasets in a relational database
Relational database
A relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...
structure.
CHS scientists reportedly conceptualized a spatio-temporal indexing system during a hydrographic survey onboard CCGS Hudson
CCGS Hudson
The CCGS Hudson is an offshore oceanographic and hydrographic survey vessel operated by the Canadian Coast Guard.The Hudson is Canada's oldest operational ocean research vessel...
on Georges Bank
Georges Bank
Georges Bank is a large elevated area of the sea floor which separates the Gulf of Maine from the Atlantic Ocean and is situated between Cape Cod, Massachusetts and Cape Sable Island, Nova Scotia ....
during the summer of 1989. The indexing system involved an adaptation of a Riemannian hypercube
Hypercube
In geometry, a hypercube is an n-dimensional analogue of a square and a cube . It is a closed, compact, convex figure whose 1-skeleton consists of groups of opposite parallel line segments aligned in each of the space's dimensions, perpendicular to each other and of the same length.An...
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
The Oracle Database is an object-relational database management system produced and marketed by Oracle Corporation....
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.
Oracle Corporation
Oracle Corporation
Oracle Corporation is an American multinational computer technology corporation that specializes in developing and marketing hardware systems and enterprise software products – particularly database management systems...
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, Quebec
Hull is the central and oldest part 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 the Canadian National Capital Region, it contains offices for twenty thousand...
during the early 1990s to redevelop the Oracle database kernel
Kernel (computing)
In computing, the kernel is the main component of most computer operating systems; it is a bridge between applications and the actual data processing done at the hardware level. The kernel's responsibilities include managing the system's resources...
. 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
Oracle Spatial forms a separately-licensed option component of the Oracle Database. Oracle Spatial aids users in managing geographic and location-data in a native type within an Oracle database, potentially supporting a wide range of applications — from automated mapping/facilities-management and...
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.