http://www.allinterview.com New Architecture Interview Questions en-us http://www.allinterview.com/showanswers/72636.html archiver will maintain the Historical data from Master data based on time. this data will be used for planning and forecasting. http://www.allinterview.com/showanswers/72635.html http://www.allinterview.com/showanswers/61882.html select sid from v$mystat where rownum=1; http://www.allinterview.com/showanswers/61870.html show sga It shows : Total System Global Area 135338868 bytes Fixed Size 453492 bytes Variable Size 109051904 bytes Database Buffers 25165824 bytes Redo Buffers 667648 bytes http://www.allinterview.com/showanswers/61869.html There are 2 basic memory structures on the Oracle Instance 1. System Global Area (SGA) 2. Program Global Area (PGA) http://www.allinterview.com/showanswers/3320.html Free extents cannot be merged together in Ver 6.0. Free extents are periodically coalesces with the neighboring free extent in Ver 7.0 http://www.allinterview.com/showanswers/3319.html Database buffer is part of SGA, Which it is contain oracle blocks copied from datafile and modification carried in this area. In oracle 9i BUFFER CACHE is divided into three parts buffer_cache, buffer_keep_cache,buffer_recycle_cahce. THANKS http://www.allinterview.com/showanswers/3318.html OPTIMAL parameter is used to set the optimal length of a rollback segment http://www.allinterview.com/showanswers/3317.html Number of times processes repeatedly query the dictionary table is called recursive hints. It is due to the data dictionary cache is too small. By increasing the SHARED_POOL_SIZE parameter we can optimize the size of Data Dictionary Cache. http://www.allinterview.com/showanswers/3316.html this can be monitored in DB_data_files http://www.allinterview.com/showanswers/3315.html this contains the commited and uncommited data stored in rollback table space prior to 9i. in 9i, it is called as undo table space. http://www.allinterview.com/showanswers/3314.html TRANSACTION RECOVERY, READ CONSISTENCY http://www.allinterview.com/showanswers/3313.html A oracle block divided into three parts. block header,pctfree,pctused. block header :its contain the information datafiles. pctfree: its a free space in a datablock for updation and insertion of a row.default is 10% of a block size.one m http://www.allinterview.com/showanswers/3312.html when ever the buffer cache is crashed, the transactions present in the buffer cache is lost. this can be recovered by the redo log buffer, which contains all the transactions present in the buffer cache http://www.allinterview.com/showanswers/3311.html SYSTEM - Data dictionary tables. DATA - Standard operational tables. DATA2- Static tables used for standard operations INDEXES - Indexes for Standard operational tables. INDEXES1 - Indexes of static tables used for standard operations. TOOLS -