The time since the current lock mode was acquired

Chapter 17 ■ Waits, enqueues, and LatChes

FROM gv$lock;
INST_ID SID TY ID1 ID2 LMODE REQUEST CTIME BLOCK---------- ---------- -- ---------- ---------- ---------- ---------- ---------- ---------- 1 10 RS 25 1 2 0 183030 2 1 239 XR 0 0 1 0 183148 2 1 10 XR 4 0 1 0 183148 2 1 10 RD 1 0 1 0 183146 2 1 9 DM 1 0 4 0 183021 2 1 9 MR 201 0 4 0 183023 2 1 10 CF 0 0 2 0 183038 2 1 247 RT 2 1 6 0 183023 2 1 9 RT 2 2 6 0 183023 2 1 249 TS 3 1 3 0 183004 2 1 241 KT 16749 0 4 0 48798 2 1 14 AE 133 0 4 0 182993 2 1 282 PS 1 32766 4 0 1 2 2 10 RS 25 1 2 0 183791 2 2 239 XR 0 0 1 0 183959 2 2 10 XR 4 0 1 0 183959 2 2 10 RD 1 0 1 0 183956 2 2 9 DM 1 0 4 0 183463 2 2 10 CF 0 0 2 0 183824 2 2 9 MR 201 8 4 0 183805 2 2 247 RT 1 0 6 0 183799 2 2 9 RT 1 2 6 0 183473 2 2 269 TM 93128 0 3 0 0 2 2 37 TM 93128 0 3 0 0 2 2 289 TM 93128 0 0 3 0 0 2 280 TM 93120 0 3 0 0 2

Chapter 17 ■ Waits, enqueues, and LatChes

In the preceding output, the enqueue timeouts gives the total number of enqueue operations that could not complete successfully and was timed out before the request was completed. The counters include both the get and convert requests.

In an Oracle RAC environment, there are two types of enqueues: the enqueues that are specific to a RAC environment and those that apply to a single-instance environment. However, both types of enqueues can have a higher impact in a RAC environment. In this section, we try to analyze few of the enqueues.

Script: MVRACPDnTap_EnqStats.sql