Oracle 8i Internal Services：for Waits, Latches, Locks, and Memory

Furnishesindepth，authoritativedataaboutOracleinternalservices，includingdatastructures，algorithms，hiddenparameters，andundocumentedsystemstatistics，withnewsectionsonlatches，memoryuseandmanagement，waits，andlocks.Original.(Intermediate)，ThisconcisebookcontainsdetailedinformationaboutOracleinternals--informationthat'snotreadilyavailabletoOraclecustomers.ItlaysafoundationforadvancedperformancetuningoftheOracledatabase.BasedonOracle8irelease8.1，thebookdescribesmanyofthesecretsofOracle'sinternalservices：datastructures，algorithms，andundocumentedOraclesystemstatistics.Maintopicsinclude：Waits-howOracleprocessescommunicateviasemaphores，andhowtousetheOraclewaitstatisticstoidentifythesourceofperformanceproblems.Latches-howtheykeepmultipleprocessesfrominspectingprotecteddatastructuresatthesametime，andhowtoexamineandcontrollatchbehaviorandstatistics.Locks-howtheyworkwithlatchestoprotectdatastructures(locksallowmultiplesessionstoshareresourcesinsomecases)，andhowlocksaffectperformance.Thereisalsoadetaileddiscussionofinstancelocks，whichareusedinparallelserverenvironments.Memory-howOracleusesmemory(e.g.，thevariouselementsoftheSystemGlobalArea)，andhowOracledynamicallyallocatesandmanagesmemory.Oracle8iInternalServicesisaimedespeciallyatadministratorsanddeveloperswhoneeddetailedinternalinformationtodoadvancedperformancetuning.ThebookwillexpandyourrepertoireoftuningsolutionsandtroubleshootingtechniquesbyexplaininghowyoucanuseOracle'shiddenparametersandundocumentedsystemstatisticstobestadvantage.NOTE：Theauthorhascollectedthescriptshehasdevelopedfortuningandanalysisintoatoolkit(knownasAPT，forAdvancedPerformanceTuning).ThesescriptsaccesstheOracleX$tablesdirectlyandprovideinformationnototherwiseavailable.ThescriptsareavailabletoreadersforfreefromtheO'Reillywebsite.