December 2012

enq: TT – contention:The TT enqueue is used to avoid deadlocks in parallel tablespace operations. The TT enqueue can be seen with parallel create tablespace and parallel point in time recovery (PITR) REFERENCE : the definitive guide SELECT DECODE(request,0,’Holder: ‘,’Waiter: ‘) || sid sid, id1, id2, lmode, request, type, inst_id FROM GV$LOCK WHERE (id1, id2,Continue reading “enq: TT – contention”

FAST COMMIT

FAST COMMIT.

FAST COMMIT

REFERENCE : ORACLE DATABASE 10g: SQL TUNING 1. The server process places a commit record, along with the scn, in the redo log buffer. 2. The LGWR performs a contiguous write of all the redo log buffer entries up to and including the commit record to the redo log files. After this point, the OracleContinue reading “FAST COMMIT”