OnetypeofdatabasecorruptionthatisreportedtoTechnicalSupportistypicallyassociatedwithAssertionError50213,"Pagenumberonpagedoesnotmatchpagerequested".WhenrunningonanASA6or7,theassertionwilllikelybe200601,"Pageforrequestedrecordnotatablepageorrecordnotpresentonpage."Mostfrequently,however,saiddatabasewascreatedonversion5.xandbecamecorruptedbeforeupgradingthesoftware.Occasionallyotherassertionsarereported,dependingontheoperationthatfirstfails.OurProductQualitydepartmenthasstatedthattheywouldprefertoreceivealldatabasesin-housethatbecomecorruptedonversionofthesoftwarethatiscurrentlybeingdeveloped（asofthiswriting,SSA5.5.05,ASA6.0.4,ASA7.0.1）inordertoinvestigatethecausesandfrequencyofdatabasecorruption.Insomecases,however,theproceduredescribedbelowcanbemoreexpedient.Furthermore,iftheyouarerunningonsoftwarethatisnolongerbeingupdated（typicallythemaintenancelevelcurrentlybeingsoldplusonelevelearlier），theusefulnessofsuchinformationislimited.Inallcasesofdatabasecorruption,thepreferredresolutionistofindavalidbackup,andapplyallofthelogfilessincethetimeofthebackup.Thistypeofcorruptionisparticularlybothersome,however,becauseitonlymanifestsitselfwhenaparticulardatabasepageisaccessed.Ifthedataonthatpageisrarelyused,thecorruptionmaywellexistonmanyorallofthebackupsthecustomerhasonhand.Itmaybepossibletorecoverthedatabasewiththefollowingprocedure,althoughitislikelythatsomedatawillbelost.Itisuptothecustomertodeterminethevalidityandcompletenessofthedataintherecovereddatabase.Youwillwanttousethedbunloadcommand;thereforeitisprudenttonotethefollowingdbunloadswitches:（atthecommandprompttype:dbunload/?）Usage:dbunload[switches]<directory>[table-name-list]Switches（usespecifiedlower-caseletter,asshown）：-c"keyword=value;…"supplydatabaseconnectionparameters-dunloaddataonly-enodataoutputforlistedtables-g<user>specifyusernameasreplacementfordbo-iiinternalunload,internalreload（default）-ixinternalunload,externalreload-j<count>iterationcountforviewcreationstatements-nnoda