Associate a type of statistics (or default statistics) with an 
  object. 
This allows you to override the CBO on a per object basis (rather than using hints for every SQL statement.)
  
Syntax:
   ASSOCIATE STATISTICS WITH
      COLUMNS [schema.]table_column,…
         USING [schema.]statistics_type;
   ASSOCIATE STATISTICS WITH
      object [schema.]object_name,…
         cost_usage_clause;
    Where object is any of
   
      FUNCTIONS
      PACKAGES
      TYPES
      INDEXES
      INDEXTYPES
cost_usage_clauses:
   USING [schema.]statistics_type
   USING NULL
   DEFAULT COST (cpu_cost, io_cost, network_cost)
   DEFAULT SELECTIVITY default_selectivity
Key:
  cpu_cost            An Integer: 0 or greater
  io_cost             An Integer: 0 or greater
  network_cost        An Integer: 0 or greater
  default_selectivity A number between 0 and 100
  statistics_type     Must already have been created. 
Examples:
ASSOCIATE STATISTICS WITH PACKAGES spud.spuds_package DEFAULT SELECTIVITY 10; 
ASSOCIATE STATISTICS WITH INDEXES My_Index DEFAULT COST (50,10,0);
ASSOCIATE STATISTICS WITH COLUMNS spud.My_Table.My_col USING spud.My_Stats;
ASSOCIATE STATISTICS WITH COLUMNS spud.My_Table.My_col USING NULL;
  "There are lies, damned lies, and statistics" - Disraeli
  
Related Oracle Commands:
DISASSOCIATE STATISTICS
DBMS_STATS  
ANALYZE
EXPLAIN PLAN
IMP with rows=y
Related Views:
DBA_PART_COL_STATISTICS ALL_PART_COL_STATISTICS USER_PART_COL_STATISTICS DBA_TAB_COL_STATISTICS ALL_TAB_COL_STATISTICS USER_TAB_COL_STATISTICS V$BUFFER_POOL_STATISTICS