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In the database management systems developed by the Oracle Corporation, the System Global Area (SGA) forms the part of the system memory (RAM) shared by all the processes belonging to a single Oracle database instance. The SGA contains all information necessary for the instance operation. == Components == In general, the SGA consists of the following: * buffer cache: holds copies of data blocks read from datafiles〔("Memory Architecture" ) in ''Oracle Database Concepts 11g Release 1 (11.1)''〕 * dictionary cache: holds information about data dictionary tables, such as information about account, datafile, segment, extent, table and privileges * redo log buffer: contains information about database transactions, both committed and uncommitted, in preparation for writing to online redo log files * shared pool: holds the dictionary or row cache, the library cache, cursor definitions and shared SQL. * Java pool: holds information for parsing Java statements. * large pool: including the User Global Area (UGA)) 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「system global area」の詳細全文を読む スポンサード リンク
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