How to gather statistics on a table in Oracle

Gather fresh optimizer statistics for one table and its indexes.

Gathering statistics changes the optimizer inputs and can change execution plans. On busy systems run it in a maintenance window.

BEGIN
  DBMS_STATS.GATHER_TABLE_STATS(
    ownname          => '&&owner',
    tabname          => '&&table_name',
    estimate_percent => DBMS_STATS.AUTO_SAMPLE_SIZE,
    method_opt       => 'FOR ALL COLUMNS SIZE AUTO',
    cascade          => TRUE,
    degree           => DBMS_STATS.AUTO_DEGREE);
END;
/

-- Verify (read-only)
SELECT num_rows,
       TO_CHAR(last_analyzed,'YYYY-MM-DD HH24:MI') AS last_analyzed
FROM   dba_tables
WHERE  owner = UPPER('&owner')
  AND  table_name = UPPER('&table_name');