DDL引发的对象invalidation

来源：互联网发布：数码宝贝2知乎编辑：程序博客网时间：2024/06/06 14:17
SQL> select * from v$sysstat a where a.STATISTIC#=339;STATISTIC# NAME  CLASS    VALUE    STAT_ID---------- ---------------------------------------------------------------- ---------- ---------- ----------       339 parse count (hard)    64    12614  143509059SQL>  select namespace,gets,pins,reloads,INVALIDATIONS from v$librarycache;NAMESPACE   GETS       PINS    RELOADS INVALIDATIONS-------------------- ---------- ---------- ---------- -------------SQL AREA      953706920  953785272 8674943TABLE/PROCEDURE   17373     145986 2048  0BODY    178       2072   29  0TRIGGER     302        436   85  0INDEX    208        472    5  0CLUSTER     715       2419    5  0OBJECT      0  0    0  0PIPE      0  0    0  0JAVA SOURCE      0  0    0  0JAVA RESOURCE      0  0    0  0JAVA DATA      0  0    0  011 rows selected.多次执行: select * from a1;稳定在SQL> /STATISTIC# NAME  CLASS    VALUE    STAT_ID---------- ---------------------------------------------------------------- ---------- ---------- ----------       339 parse count (hard)    64    12661  143509059SQL> /NAMESPACE      GETS PINS RELOADS INVALIDATIONS--------------- ---------- ---------- ---------- -------------SQL AREA 953707073  953786218    8680   944TABLE/PROCEDURE      17465     146209    2060     0BODY       180 2076      29     0TRIGGER        307  441      85     0INDEX       208  472       5     0CLUSTER        725 2440       5     0OBJECT 0    0       0     0PIPE 0    0       0     0JAVA SOURCE 0    0       0     0JAVA RESOURCE 0    0       0     0JAVA DATA 0    0       0     011 rows selected.进行ddl测试；alter table a1 modify  name char(200);此时硬解析前后对比:SQL> /STATISTIC# NAME  CLASS    VALUE    STAT_ID---------- ---------------------------------------------------------------- ---------- ---------- ----------       339 parse count (hard)    64    12709  143509059SQL> /STATISTIC# NAME  CLASS    VALUE    STAT_ID---------- ---------------------------------------------------------------- ---------- ---------- ----------       339 parse count (hard)    64    12713  143509059INVALIDTION前后对比:SQL> /NAMESPACE      GETS PINS RELOADS INVALIDATIONS--------------- ---------- ---------- ---------- -------------SQL AREA 953707179  953787022    8686   950TABLE/PROCEDURE      17526     146463    2081     0BODY       180 2088      29     0TRIGGER        311  445      85     0INDEX       208  472       5     0CLUSTER        731 2463       5     0OBJECT 0    0       0     0PIPE 0    0       0     0JAVA SOURCE 0    0       0     0JAVA RESOURCE 0    0       0     0JAVA DATA 0    0       0     011 rows selected.SQL> /NAMESPACE      GETS PINS RELOADS INVALIDATIONS--------------- ---------- ---------- ---------- -------------SQL AREA 953707215  953787112    8688   953TABLE/PROCEDURE      17528     146525    2082     0BODY       180 2092      29     0TRIGGER        315  449      85     0INDEX       208  472       5     0CLUSTER        731 2463       5     0OBJECT 0    0       0     0PIPE 0    0       0     0JAVA SOURCE 0    0       0     0JAVA RESOURCE 0    0       0     0JAVA DATA 0    0       0     011 rows selected.
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