Database Queries.

Queries of the global surface database will be made by agricultural planners, economic planners, city planners, climate modelers, sociological studies, political studies, etc. We anticipate upwards of queries per day or 12 queries per second, each query requiring correlations over varying regions of the database.

The processed database is approximately bytes. Some queries will use substantial portions of the database and the queries will need to be answered on the order minutes. (For reference, the United States is of the land mass of the planet.) A query that needs access to the entire database in five minutes would require a bandwidth of terabytes per second. Accessing a single model set for each grid point in the United States in five minutes requires bandwidth of gigabytes per second.

The table in Figure 4.3 estimates the computational cost required for different classes of queries. It is assumed that queries per day are to be processed and each is identical. Three different size queries are estimated: (1) one that uses the entire data contained in the database, (2) one that uses the data corresponding to one sample for each grid point in the United States, and (3) one that uses the data corresponding to one sample for each grid point on a acre farm. In addition, it is assumed that the computation required to handle the query is either linear, , or quadratic.

Clearly, peta-operation machines will have difficulties with these query rates if a query requires more than linear processing. However, even large-scale queries that deal with all of the archived information can (barely) be handled by peta-machines if efficient (linear) algorithms can be developed.