System Global Area

System Global Area

System Global Area (SGA) nennt man die prozessübergreifenden Speicherbereiche im Hauptspeicher des Datenbankservers einer Oracle Datenbank. Dort liegen alle notwendigen Daten für die Instanz-Operationen.

In diesem Speicherbereich befindet sich

  • Buffer Cache: Hier werden Datenblöcke zwischengespeichert, die von der Platte gelesen werden. Dies ermöglicht es, beim mehrmaligen Zugriff auf Datenblöcke diese aus dem Cache zu lesen, anstatt diese jeweils erneut von der Platte zu lesen.
  • Dictionary Cache: Er enthält Informationen über Data Dictionary-Tabellen, dazu gehören Informationen über Benutzerkonten , Datenbankdateien, Segmente, Extents, Tabellen und Rechte (privileges).
  • Redo Log Buffer: Er enthält Informationen über abgeschlossene Transaktionen, die noch nicht in die Online Redo Log Dateien geschrieben wurden.
  • Shared Pool: Hier werden u.a. die zuletzt benutzten SQL-Befehle und ihre Ausführungspläne sowie der Dictionary Cache (s.o.) gespeichert.
  • JAVA Pool (optional): Zur Analyse der Java-Befehle.

Weblinks


Wikimedia Foundation.

Игры ⚽ Нужен реферат?

Schlagen Sie auch in anderen Wörterbüchern nach:

  • System Global Area — In the database management systems developed by the Oracle Corporation, the System Global Area (SGA) forms the part of the RAM shared by all the processes belonging to a single Oracle database instance. The SGA contains all information necessary… …   Wikipedia

  • Global Area Reference System — The Global Area Reference System is a standardized geospatial reference system proposed by the National Geospatial Intelligence Agency (NGA) for use across the United States Department of Defense. It is somewhat similar to the Military grid… …   Wikipedia

  • Broadband Global Area Network — A Broadband Global Area Network or BGAN for short, is a form of Satellite internet and telephony provided by INMARSAT. The system uses two geostationary satellites, with a third satellite expected to enter service later in 2008. The system will… …   Wikipedia

  • Global navigation satellite system — (GNSS) is the standard generic term for satellite navigation systems that provide autonomous geo spatial positioning with global coverage. A GNSS allows small electronic receivers to determine their location (longitude, latitude, and altitude) to …   Wikipedia

  • Global Air Traffic Management — (GATM) is a concept for satellite based communication, navigation, surveillance and air traffic management. The Federal Aviation Administration and the International Civil Aviation Organization, a special agency of the United Nations, established …   Wikipedia

  • Global warming controversy — refers to a variety of disputes, significantly more pronounced in the popular media than in the scientific literature,[1][2] regarding the nature, causes, and consequences of global warming. The disputed issues involve the causes of increased… …   Wikipedia

  • Global dimming — is the gradual reduction in the amount of global direct irradiance at the Earth s surface that was observed for several decades after the start of systematic measurements in 1950s. The effect varies by location, but worldwide it has been… …   Wikipedia

  • Global Gathering 2005 — was held on Friday 29th July 2005 (5pm 2am) and Saturday 30th July 2005 (2pm 6am) at Long Marston Airfield, near Stratford upon Avon, Warwickshire, England. Global Gathering is the name of an annual dance music festival organised by the… …   Wikipedia

  • Global governance — is the political interaction of transnational actors aimed at solving problems that affect more than one state or region when there is no power of enforcing compliance. Traditionally, governance has been associated with governing, or with… …   Wikipedia

  • Global health — is a field at the intersection of several social science disciplines demography, economics, epidemiology, political economy and sociology. It focuses on determinants and distribution of health in international contexts. The term global health… …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”