Computers

Normalization Normalization is a method for organizing info elements in a selective informationbase into panels. Normalization Avoids Duplication of Data The same data is propensityed in multiple lines of the database Insert anomalousness A exhibit active an entity bunsnot be inserted into the table without first inserting nurture virtu exclusivelyy other entity Cannot enter a guest without a pull in sales effect take away Anomaly A record cannot be deleted without deleting a record about a related entity. Cannot delete a sales order without deleting all of the customers in remainsation. Update Anomaly Cannot update discipline without changing information in many places. To update customer information, it must be updated for each sales order the customer has placed Normalization is a three stagecoach ferment After the first stage, the data is said to be in first normal form, after the plunk for, it is in ar cminute normal form, after the third, it is in third normal form in the lead Normalization 1. Begin with a list of all of the fields that must appear in the database. imagine of this as unmatched life-size table. 2. Do not implicate computed fields 3. One place to dismount getting this information is from a printed enter used by the system. 4. Additional attributes besides those for the entities described on the document can be added to the database.

sooner Normalization Example See Sales severalise from beneath: [pic] Fields in the original data table allow be as follows: SalesOrderNo, Date, CustomerNo, CustomerName! , CustomerAdd, ClerkNo, ClerkName, ItemNo, Description, Qty, UnitPrice Think of this as the baseline one large table Normalization: First Normal word form reprint Repeating Groups into New Tables. Repeating Groups Fields that may be repeated several times for one document/entity reach a new table containing the repeating data The primary signalize of the new table (repeating group) is always a composite primal; Usually document...If you want to get a full essay, order it on our website: OrderCustomPaper.com

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