2014.8.6學習Oracle記錄:set autotrace on

  開啓Oracle跟蹤的語句set autotrace on要在sqlplus環境中運行，在PL/SQL Developer中執行始終彈出cannot set autotrace。加了索引的SQL，查詢速度會很快！

Oracle統計信息，還不明白是什麼意思

9 recursive calls

0 db block gets

61 consistent gets

4 physical reads

0 redo size

420 bytes sent via SQL*NET to client

400 bytes received via SQL*NET from client

2 SQL*NET roundtrips to/from client

0 sorts(memory)

0 sorts(disk)

1 rows processed