Shulou(Shulou.com)05/31 Report--

Today, I will talk to you about the steps to solve latch cache buffers chains. Many people may not know much about it. In order to make you understand better, the editor has summarized the following for you. I hope you can get something according to this article.

Latch:cache buffers chains resolution steps

The cause of the problem:

One day when I checked the v$session_wait, I found that there were a lot of cache buffer chains, but the situation was urgent, so I just killed a few sql that had been executed for a long time, and then found that the waiting event gradually disappeared.

Find out why this wait event is caused:

1. First find the ash of the time when the problem occurs.

SQL > create table mao_ash as select * from dba_hist_active_sess_history where SAMPLE_TIME between TO_TIMESTAMP ('2013-12-27 10 from dba_hist_active_sess_history where SAMPLE_TIME between TO_TIMESTAMP,' YYYY-MM-DD HH24:MI:SS') and TO_TIMESTAMP ('2013-12-27 12 YYYY-MM-DD HH24:MI:SS')

2. Verify the issue time frame:

Select / * + parallel 8 * / instance_number,sample_id, sample_time, count (*) from mao_ash t

Group by instance_number,sample_id, sample_time

Order by 3

INSTANCE_NUMBER SAMPLE_ID SAMPLE_TIME COUNT (*)

2 72736930 2013-12-27 11 purl 14 purl 48.374 1

1 72762620 2013-12-27 11 Suzhou 14 purl 51.059 11

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