Oracle中的父闩大致可以分成2类：有子闩的父闩或者独居的父闩，我们来看看这些父闩的属性:
SQL> select * from v$version;
BANNER
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Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bi
PL/SQL Release 10.2.0.4.0 - Production
CORE 10.2.0.4.0 Production
TNS for IBM/AIX RISC System/6000: Version 10.2.0.4.0 - Productio
NLSRTL Version 10.2.0.4.0 - Production
SQL> select count(distinct name) from v$latch_children;
COUNT(DISTINCTNAME)
-------------------
82
/* 10.2.0.4下共有82种不同子闩，同比11.2.0.1是75种，要比10g中少一些，因为一部分闩在11g中被mutex替代了 */
