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Updating tables in a database

Databases are used to hold administrative information and more specialized data, such as engineering data or economic models.Examples of database applications include computerized library systems, flight reservation systems, computerized parts inventory systems, and many content management systems that store websites as collections of webpages in a database.Computer scientists may classify database-management systems according to the database models that they support; the most popular database systems since the 1980s have all supported the relational model - generally associated with the SQL language.Formally, a "database" refers to a set of related data and the way it is organized.Following the technology progress in the areas of processors, computer memory, computer storage, and computer networks, the sizes, capabilities, and performance of databases and their respective DBMSs have grown in orders of magnitude.The development of database technology can be divided into three eras based on data model or structure: navigational, SQL/relational, and post-relational.Because of the close relationship between them, the term "database" is often used casually to refer to both a database and the DBMS used to manipulate it.Outside the world of professional information technology, the term database is often used to refer to any collection of related data (such as a spreadsheet or a card index).

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Physically, database servers are dedicated computers that hold the actual databases and run only the DBMS and related software.Application programmers may use a wire protocol directly, or more likely through an application programming interface.Database designers and database administrators interact with the DBMS through dedicated interfaces to build and maintain the applications' databases, and thus need some more knowledge and understanding about how DBMSs operate and the DBMSs' external interfaces and tuning parameters.General-purpose DBMSs aim to meet the needs of as many applications as possible, which adds to the complexity.However, since their development cost can be spread over a large number of users, they are often the most cost-effective approach.Database servers are usually multiprocessor computers, with generous memory and RAID disk arrays used for stable storage.RAID is used for recovery of data if any of the disks fail.Database designers typically organize the data to model aspects of reality in a way that supports processes requiring information, such as (for example) modelling the availability of rooms in hotels in a way that supports finding a hotel with vacancies.A database-management system (DBMS) is a computer-software application that interacts with end-users, other applications, and the database itself to capture and analyze data.A general-purpose DBMS allows the definition, creation, querying, update, and administration of databases.A database is not generally portable across different DBMSs, but different DBMSs can interoperate by using standards such as SQL and ODBC or JDBC to allow a single application to work with more than one DBMS.

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  1. If you maintain data for a rolling time period, use a series of tables, as the following diagram illustrates.

  2. Updating Rainfall Frequency Analysis in Bulletin 195 Climate Data Collection and Forecasting Element California Department of Water Resources

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