SQL> select count(*) from hr.employees;
SQL> select namespace,pins,reloads,invalidations  from v$librarycache;
SQL> ANALYZE TABLE hr.employees COMPUTE STATISTICS;
SQL> select count(*) from hr.employees;
SQL> select namespace,pins,reloads,invalidations from v$librarycache;

// When Invalidations Occur ?
when a table, sequence, synonym, or view is re-created or altered or dropped, or a procedure or package specification is recompiled, all dependent shared SQL areas are invalidated.

Additional V$SQL_PLAN columns not found in PLAN_TABLE:
• ADDRESS: Cursor parent handle address
• HASH_VALUE: Parent statement hash value in library cache
• CHILD_NUMBER: Number using this execution plan
• DEPTH: Level of the operation in the tree
• CPU_COST: CPU cost of the operation as estimated by the cost-based optimizer. If using the rule-based optimizer, this column is null.
• IO_COST: Cost of the operation as estimated by the cost-based optimizer. If using the rule-based optimizer, this column is Null.
• TEMP_SPACE: Space usage of sort or hash-join estimated by cost-based optimizer