Doc Type: Tuning | SubType: | Cible: Latches | Desc: Les latches | ************************************************************** (miss/get)*100 idem pour immediat -> doit être < 1% Si CACHE BUFFERS CHAIN LATCH > 1% -> + DB_BLOC_BUFFER Si CACHE BUFFERS LRU CHAIN LATCH > 1% -> + DB_BLOC_BUFFER et + DB_BLOC_WRITE_BATCH Si REDO ALLOCATION LATCH > 1% et multi-CPU -> - LOG_SMALL_ENTRY_SIZE Si REDO COPY LATCH > 1% et multi-CPU -> + LOG_SIMULTANEOUS_COPIES (2*nb CPU) et/ou - LOG_ENTRY_PREBUILD_THRESOLD Si ROW CACHE OBJECTS LATCH > 1% -> + SHARED_POOL_SIZE ************************************************************** # set feed off set pages 70 col name format a30 select p2,w.wait_time from v$session_wait w,v$session s,v$latch l where w.wait_time>40000000; prompt Detail prompt _______ select n.name,gets,misses,immediate_gets "imd_gets", immediate_misses "imd_misses" from v$latchname n,v$latch l where n.latch#=l.latch# order by n.name;