²é¿´oracleÖ´Ðмƻ®
³£Ó÷½·¨ÓÐÒÔϼ¸ÖÖ£º
Ò»¡¢Í¨¹ýPL/SQL Dev¹¤¾ß
1¡¢Ö±½ÓFile->New->Explain Plan Window£¬ÔÚ´°¿ÚÖÐÖ´ÐÐsql¿ÉÒԲ鿴¼Æ»®½á¹û¡£ÆäÖУ¬Cost±íʾcpuµÄÏûºÄ£¬µ¥Î»Îªn%£¬Cardinality±íʾִÐеÄÐÐÊý£¬µÈ¼ÛRows¡£
2¡¢ÏÈÖ´ÐÐ EXPLAIN PLAN FOR select * from tableA where paraA=1£¬ÔÙ select * from table(DBMS_XPLAN.DISPLAY)±ã¿ÉÒÔ¿´µ½oracleµÄÖ´Ðмƻ®ÁË£¬¿´µ½µÄ½á¹ûºÍ1ÖеÄÒ»Ñù£¬ËùÒÔʹÓù¤¾ßµÄʱºòÍÆ¼öʹÓÃ1·½·¨¡£
×¢Ò⣺PL/SQL Dev¹¤¾ßµÄCommand windowÖв»Ö§³Öset autotrance onµÄÃüÁî¡£»¹ÓÐʹÓù¤¾ß·½·¨²é¿´¼Æ»®¿´µ½µÄÐÅÏ¢²»È«£¬ÓÐЩʱºòÎÒÃÇÐèÒªsqlplusµÄÖ§³Ö¡£
¶þ¡¢Í¨¹ýsqlplus
1¡¢Ò»°ãÇé¿ö¶¼ÊDZ¾»úÁ´½ÓÔ¶³Ì·þÎñÆ÷£¬ËùÒÔÃüÁîÈçÏ£º
sqlplus user/pwd@serviceName
´Ë´¦µÄserviceNameΪtnsnames.oraÖж¨ÒåµÄÃüÃû¿Õ¼ä¡£
2¡¢Ö´ÐÐset autotrace on£¬È»ºóÖ´ÐÐsqlÓï¾ä£¬»áÁгöÒÔÏÂÐÅÏ¢£º
¡£¡£¡££¨Ê¡ÂÔһЩÐÅÏ¢£©
ͳ¼ÆÐÅÏ¢
----------------------------------------------------------
1 recursive calls £¨¹éµ÷ÓôÎÊý£©
0 db block gets
2 consistent gets
0 physical reads £¨ÎïÀí¶Á——Ö´ÐÐSQLµÄ¹ý³ÌÖУ¬´ÓÓ²ÅÌÉ϶ÁÈ¡µÄÊý¾Ý¿é¸öÊý£©
0 redo size (ÖØ×öÊý——Ö´ÐÐSQLµÄ¹ý³ÌÖУ¬²úÉúµÄÖØ×öÈÕÖ¾µÄ´óС)
358 bytes sent via SQL*Net to client
366 bytes received via SQL*Net from client
1 SQL*Net roundtrips to/from client
0 sorts (memory)  
Ïà¹ØÎĵµ£º
Oracle ×Ö¶ÎÀàÐÍ
×Ö¶ÎÀàÐÍ
ÃèÊö
×ֶγ¤¶È¼°Æäȱʡֵ
CHAR (size )
ÓÃÓÚ±£´æ¶¨³¤(size)×Ö½ÚµÄ×Ö·û´®Êý¾Ý¡£
ÿÐж¨³¤£¨²»×㲿·Ö²¹Îª¿Õ¸ñ£©£»×î´ó³¤¶ÈΪÿÐÐ2000×Ö½Ú£¬È±Ê¡ÖµÎªÃ¿ÐÐ1×Ö½Ú¡£ÉèÖó¤¶È(size)ǰÐ迼ÂÇ×Ö·û¼¯Îªµ¥×Ö½Ú»ò¶à×Ö½Ú¡£
VARCHAR2 (size )
ÓÃÓÚ±£´æ±ä³¤µÄ×Ö·û´®Êý¾Ý¡£ÆäÖÐ×î´ó×Ö½Ú³¤ ......
max_commit_propagation_delayĬÈÏֵΪ700£¬¼´7Ã루µ¥Î»0.01s£¬http://www.orafaq.com/parms/parm1217.htm£©¡£
Õâ¸ö²ÎÊýÓ¦¸ÃÅäÖõÄÊÇRAC£¨Real Application Cluster£©Ö®¼äͬ²½Êý¾ÝµÄƵÂÊ¡£ÐÞ¸ÄÕâ¸ö²ÎÊýµÄºÃ´¦¾Í²»ÓÃ˵ÁË£¨
±¾ÈËÉîÊÜÆä¿à°¡
£©£¬µ«ÊÇÈç¹û×ßÁíÒ»¸ö¼«¶Ë£¬¿ÉÄÜ»á¸øÊý¾Ý¿âÔì³É¸ü´óµÄѹÁ¦
²ÎÊýÖ¸¶¨Ò»¸öinstance ......
±¾ÎÄͨ¹ý¶ÔOracleÊý¾Ý¿âËø»úÖÆµÄÑо¿£¬Ê×ÏȽéÉÜÁËOracleÊý¾Ý¿âËøµÄÖÖÀ࣬²¢ÃèÊöÁËʵ¼ÊÓ¦ÓÃÖÐÓöµ½µÄÓëËøÏà¹ØµÄÒì³£Çé¿ö£¬Ìرð¶Ô¾³£Óöµ½µÄÓÉÓڵȴýËø¶øÊ¹ÊÂÎñ±»¹ÒÆðµÄÎÊÌâ½øÐÐÁ˶¨Î»¼°½â¾ö£¬²¢¶ÔËÀËøÕâÒ»±È½ÏÑÏÖØµÄÏÖÏó£¬Ìá³öÁËÏàÓ¦µÄ½â¾ö·½·¨ºÍ¾ßÌåµÄ·ÖÎö¹ý³Ì¡£
Êý¾Ý¿âÊÇÒ»¸ö¶àÓû§Ê¹ÓõĹ ......
ÓÐÈçϱíTest
City People Make
¹ãÖÝ 1 A
¹ãÖÝ 2 B
¹ãÖÝ 3 C
ÉϺ£ 4 A
ÉϺ£ 5 ......