oracle培訓(xùn)講義-閱讀頁
2025-05-01 12:33本頁面
【正文】 on set sort_area_size=0。SQL set autotrace traceonly statisticsSQL select * from t order by object_id。Statistics 0 recursive calls 24 db block gets 80 consistent gets 214 physical reads 0 redo size 219216 bytes sent via SQL*Net to client 767 bytes received via SQL*Net from client 26 SQL*Net roundtrips to/from client 0 sorts (memory) 1 sorts (disk) 6219 rows processedSQL /已選擇6219行。會話已更改。已選擇6219行。Statistics 0 recursive calls 59 db block gets 80 consistent gets 437 physical reads 0 redo size 219216 bytes sent via SQL*Net to client 767 bytes received via SQL*Net from client 26 SQL*Net roundtrips to/from client 0 sorts (memory) 1 sorts (disk) 6219 rows processedSQL alter session set sort_area_size=102400。SQL select * from t order by object_id。Statistics 0 recursive calls 19 db block gets 80 consistent gets 198 physical reads 0 redo size 219216 bytes sent via SQL*Net to client 767 bytes received via SQL*Net from client 26 SQL*Net roundtrips to/from client 0 sorts (memory) 1 sorts (disk) 6219 rows processedSQL alter session set sort_area_size=10240000。SQL select * from t order by object_id。Statistics 0 recursive calls 0 db block gets 80 consistent gets 0 physical reads 0 redo size 219216 bytes sent via SQL*Net to client 767 bytes received via SQL*Net from client 26 SQL*Net roundtrips to/from client 1 sorts (memory) 0 sorts (disk) 6219 rows processedSQL alter session set sort_area_size=0。SQL select * from t order by object_id。Statistics 0 recursive calls 22 db block gets 80 consistent gets 212 physical reads 0 redo size 219216 bytes sent via SQL*Net to client 767 bytes received via SQL*Net from client 26 SQL*Net roundtrips to/from client 0 sorts (memory) 1 sorts (disk) 6219 rows processed252。在歸檔模式下，要把表設(shè)置為nologging，insert數(shù)據(jù)時，加上append提示。insert /*+ append */ into test_redo select * from all_objects。如果表建有索引，則要把索引停用，否則依然有大量的redo：alter index idx_test unusable。alter index idx_test rebuild nologging。 sql*net statistics252。SQL alter system set timed_statistics=true。SQL conn scott/tigerSQL select * from dept。sessionid39。Cpu：語句執(zhí)行花費的cpu時間，以1/1000秒為單位。如果cpu超過elapsed，是因為計時精確度的不同所引起的誤差，實際是不可能存在這種情況的。Qurey：consistent reads(gets)。Rows：在select操作中，出現(xiàn)在fetch欄目，在修改操作中，出現(xiàn)在execute欄目中。5) 當(dāng)設(shè)置set event時，在報告的最后將出現(xiàn)wait events：alter session set events ‘10046 trace name context forever,level 12’15 /
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