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Chapter 13: Database Administration – Microsoft SQL ServerVerify Database ConsistencyIn a database management system, consistency can be represented from the logical andphysical levels. R/3 must insure a logical consistency when communicating with the SQLServer engine, and SQL Server must insure a physical consistency for the database.Sometimes a physical inconsistency can occur in the database’s internal structures. Thisproblem occurs when R/3 “thinks” the data is, and where the data actually is, in thedatabase are different.SQL Server uses the DBCC CHECKDB command to correct and repair the database to aconsistent state. This is executed using: CCMS Scheduling calendar (DB13) The SQL Server Enterprise ManagerThe consistency checks should be done during non-peak hours or when R/3 users areoffline. For those coming from SQL Server 6.5 environments, SQL Server 7.0 executes theDBCC CHECKDB job much faster than SQL Server 6.5.Database objects statistics help make data access more efficient.The optimizer of the database engine will perform better if the table index’s statisticalinformation is current. This information helps R/3 find an item in the database faster.By default, SQL Server 7.0 has automatic statistics turned on. The possibility of manuallyscheduling update statistics using the CCMS scheduling calendar still exists. Examples ofwhen this scheduling might be necessary after large data inserts or deletes from a giventable (for example, client copy, BDC sessions, and archiving).System Administration Made Easy13–29