An HDF-EOS DataBlade using Informix’s Object-

Relational Database

Renu Chaudhry ECOlogic www.ecologic.net

Topics

What is an ORDBMS ? INFORMIX-Universal Server Architecture DataBlade Architecture HDFEOS DataBlade Components HDFEOS DataBlade Benefits User Scenario Summary

ORDBMS : Object-Relational Database Management System

What is an ORDBMS ?

OO features complex data object data behaviors (functions) inheritance and overloading

RDBMS features flexibility, security, transactions, recovery Native SQL parsing, optimization data access methods (use of R-tree & B-tree indexes)

INFORMIX-Universal Server Architecture

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ScaleableScaleableData Data

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DataBladeDataBladeModuleModule

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INFORMIX-Universal ServerExtending the server byadding DataBlades

TablesTables

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DataBlade Architecture

Data Types to define new information or data structures

Routines that act upon the new data types

Tables containing new data types

Fast indexing and access for new data types

Client API

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New data types: Grid, Swath, Point

Routines: data inquiry functions, subsetting functions as referred in HDF-EOS library

HDFEOS indexing methods for sorting and storing data

Tables containing HDF-EOS metadata and data

Client oriented code for data processing

HDF-EOS Datablade components will include:

HDFEOS Datablade

HDFEOS DataBlade Benefits

Access cross granule information via SQL

Easy browsing

Improved performance with use of built-in index

Portability - data and functions packaged inside database server

Ease of integration with other data types

Queries

Results

INFORMIX-Universal Server

A user wishes to perform a correlation study between different physicalparameters for a specific geographical area. example: Correlation between cloud amount and precipitation

HDFEOS User Scenario

User issues query to view all grid data objects that covers Bermuda. The query returns all granule names, grid information (names,

dimensions, projection, fields etc.) matching the criteria.

User issues query to retrieve data of interest. Query returns data of interest

Sample Scenario

select Grd.filename, Grd.name, Grd.projection, Grd.dimensions, Fld.fieldname

from HEOSgrid Grd, HEOSgdfield Fld

where ((Grd.filename = Fld.filename and Grd.objid = Fld.gridid) and Contains(Grd, '(32, 70, 42, 60)');

User Scenario cont’d

Query to retrieve subset of data (“Precip” field)select LatLonSubset(Fld, '(32, 70, 42, 60)')

from HEOSgdfield Fld

where Fld.filename = 'pathfinder_flat_month.8708.psg.hdfeos' and

Fld.gridname = ’SSMI' and

Fld.fieldname = ’Precip';

Query to retrieve entire granule execute HEOSretrv((granulename, outfile , location);

HDFEOS Datablade Summary

Easy access and manipulation of HDF-EOS grid, swath, point data types via SQL3

Data and the functions reside inside database for better performance

Structural metadata search across granules by simple SQL Only SQL knowledge required by novice USERS to access HDF-

EOS data Database provides data reliability, security, portability, extensibility,

transaction, performance Datablade provides flexibility to incorporate HDF data objects

A user wishes to perform a correlation study between different physicalparameters for a specific geographical area. example: Correlation between cloud amount and precipitation

HDFEOS User Scenario

User issues query to view all grid data objects that covers Bermuda. The query returns all granule names, grid information (names,

dimensions, projection, etc.) matching the criteria.

User issues query to view fieldnames from granules/grids of interest Query returns fieldnames contained in the grid

User issues query to retrieve data of interest. Query returns data of interest

Sample Scenario

select * from HEOSgrid Grd where Contains(Grd, '(32, 70, 42, 60)');

Scenario - select fields

Query to list all fieldnames contained in the specified grid objects

select filename, gridname, fieldname from HEOSgdfield where ((gridname = ‘SSMI’ and filename = ‘xxxx’) and (gridname = ‘CloudAmt’ and filename = ‘yyyy’));

OR

select filename gridname fieldname

HDF-EOS search queries

To get summary of all filenames, their size and the number of objects in each data file residing in the database:

select orgfile, size, numobj from HEOSfile;

To retrieve core, product specific, or archive metadata from specific HDF-EOS data file:

select core-metadata, product-metadata from hdfeos where orgfile=‘toms_monthly_498.HEOSfile’;