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Index Clusters More DBA job interview questions and answers at
http://dba.fyicenter.com/Interview-Questions/
(Continued from previous question...) 89. Index Clusters Index Clusters are group of one or more tables physically stored together because they share common columns & are often used together. The related columns of the tables in a cluster is called cluster key. The data in a cluster key of an index cluster is store only once for multiple tables, so disk access time improves. Hash Clusters : Also cluster table data in a manner similar to normal cluster. A row is stored in a hash cluster based on the result of applying a hash function to the row??s cluster key value. All rows with the same hash key value are stored together on disk. Hash clusters are better than using indexed table or indexed clusters when a table is queried with equality queries. For such queries, the specified cluster key is hashed. The resulting hash key value points directly to the area on disk that stores the specified rows. (Continued on next question...)
Other Job Interview Questions
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