Latch contention

Library cache latch contention is typically caused by NOT using bind variables. It is due to excessive parsing of statements. Cache buffers chain latches contention is typically caused by concurrent access to a very “hot” block and the most common type of such a hot block is an index root or branch block (since any […]

Wait time percentage

How the Oracle DBA can find the Wait time percentage of the total DB time during the last hour. DBA Oracle Compatibility: Oracle 11g Creator: Cyrille MODIANO – Montreal SELECT metric_name, ROUND(AVG(value),1) « Average Wait time % » FROM v$sysmetric_history WHERE metric_name = ‘Database Wait Time Ratio’ GROUP BY metric_name;