最近在客户的一个案例中，遇到Latch : Library Cache的竞争，其竞争位于kglic函数调用。
以下是关于KGLIC函数的功能简要说明：
1. kglic means Kernel Generic Library cache Iterate Chain (AFAIK), it's the function which is executed when you access most X$KGL tables.
2. kglic is the code which goes through the library cache and row cache to answer queries on various dictionary fixed views and tables. This is the function which returns data for the fixed views and tables that scan the sql area. Therefore, it was highly possible that such queries could also be coming from monitoring tools used by DBAs and they are not restricted to the two views specifically mentioned in the bug by Joan. Any monitoring job which looks at v$open_cursor would also use the kglic iterator.
与此相关的BUG，在10g中仍然存在，最后确认客户有较为频繁的查询访问v$sql视图，导致了严重的library cache的竞争。
以下BUG的影响版本为10.2.0.4，10.2.0.5，11.2.0.2 ：
Bug 9287616 - Accessing [G]V$SQL or [G]V$SQLTEXT_WITH_NEWLINES may be slow / takes a long time / latch contention (Doc ID 9287616.8)
以下是关于KGLIC函数的功能简要说明：
1. kglic means Kernel Generic Library cache Iterate Chain (AFAIK), it's the function which is executed when you access most X$KGL tables.
2. kglic is the code which goes through the library cache and row cache to answer queries on various dictionary fixed views and tables. This is the function which returns data for the fixed views and tables that scan the sql area. Therefore, it was highly possible that such queries could also be coming from monitoring tools used by DBAs and they are not restricted to the two views specifically mentioned in the bug by Joan. Any monitoring job which looks at v$open_cursor would also use the kglic iterator.
与此相关的BUG，在10g中仍然存在，最后确认客户有较为频繁的查询访问v$sql视图，导致了严重的library cache的竞争。
以下BUG的影响版本为10.2.0.4，10.2.0.5，11.2.0.2 ：
Bug 9287616 - Accessing [G]V$SQL or [G]V$SQLTEXT_WITH_NEWLINES may be slow / takes a long time / latch contention (Doc ID 9287616.8)
「喜欢这篇文章，您的关注和赞赏是给作者最好的鼓励」
关注作者
【版权声明】本文为墨天轮用户原创内容，转载时必须标注文章的来源（墨天轮），文章链接，文章作者等基本信息，否则作者和墨天轮有权追究责任。如果您发现墨天轮中有涉嫌抄袭或者侵权的内容，欢迎发送邮件至：contact@modb.pro进行举报，并提供相关证据，一经查实，墨天轮将立刻删除相关内容。
