DDL引发的对象invalidation

SQL> select * from v$sysstat a where a.STATISTIC#=339;

STATISTIC# NAME 								 CLASS	    VALUE    STAT_ID
---------- ---------------------------------------------------------------- ---------- ---------- ----------
       339 parse count (hard)							    64	    12614  143509059


SQL>  select namespace,gets,pins,reloads,INVALIDATIONS from v$librarycache;

NAMESPACE		   GETS       PINS    RELOADS INVALIDATIONS
-------------------- ---------- ---------- ---------- -------------
SQL AREA	      953706920  953785272	 8674		943
TABLE/PROCEDURE 	  17373     145986	 2048		  0
BODY			    178       2072	   29		  0
TRIGGER 		    302        436	   85		  0
INDEX			    208        472	    5		  0
CLUSTER 		    715       2419	    5		  0
OBJECT			      0 	 0	    0		  0
PIPE			      0 	 0	    0		  0
JAVA SOURCE		      0 	 0	    0		  0
JAVA RESOURCE		      0 	 0	    0		  0
JAVA DATA		      0 	 0	    0		  0

11 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  143509059

SQL> /

NAMESPACE	      GETS	 PINS	 RELOADS INVALIDATIONS
--------------- ---------- ---------- ---------- -------------
SQL AREA	 953707073  953786218	    8680	   944
TABLE/PROCEDURE      17465     146209	    2060	     0
BODY		       180	 2076	      29	     0
TRIGGER 	       307	  441	      85	     0
INDEX		       208	  472	       5	     0
CLUSTER 	       725	 2440	       5	     0
OBJECT			 0	    0	       0	     0
PIPE			 0	    0	       0	     0
JAVA SOURCE		 0	    0	       0	     0
JAVA RESOURCE		 0	    0	       0	     0
JAVA DATA		 0	    0	       0	     0

11 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  143509059

SQL> /

STATISTIC# NAME 								 CLASS	    VALUE    STAT_ID
---------- ---------------------------------------------------------------- ---------- ---------- ----------
       339 parse count (hard)							    64	    12713  143509059

INVALIDTION前后对比:
SQL> /

NAMESPACE	      GETS	 PINS	 RELOADS INVALIDATIONS
--------------- ---------- ---------- ---------- -------------
SQL AREA	 953707179  953787022	    8686	   950
TABLE/PROCEDURE      17526     146463	    2081	     0
BODY		       180	 2088	      29	     0
TRIGGER 	       311	  445	      85	     0
INDEX		       208	  472	       5	     0
CLUSTER 	       731	 2463	       5	     0
OBJECT			 0	    0	       0	     0
PIPE			 0	    0	       0	     0
JAVA SOURCE		 0	    0	       0	     0
JAVA RESOURCE		 0	    0	       0	     0
JAVA DATA		 0	    0	       0	     0

11 rows selected.

SQL> /

NAMESPACE	      GETS	 PINS	 RELOADS INVALIDATIONS
--------------- ---------- ---------- ---------- -------------
SQL AREA	 953707215  953787112	    8688	   953
TABLE/PROCEDURE      17528     146525	    2082	     0
BODY		       180	 2092	      29	     0
TRIGGER 	       315	  449	      85	     0
INDEX		       208	  472	       5	     0
CLUSTER 	       731	 2463	       5	     0
OBJECT			 0	    0	       0	     0
PIPE			 0	    0	       0	     0
JAVA SOURCE		 0	    0	       0	     0
JAVA RESOURCE		 0	    0	       0	     0
JAVA DATA		 0	    0	       0	     0

11 rows selected.