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September 15, 2005

我的哈根达斯月饼

作者:eygle

出处:http://blog.eygle.com

昨天费了好大力气终于取回了我的哈根达斯冰激淋月饼，装了半盒干冰，提回公司。
一盒有四个，平均50元一个。
Haagen-Dazs0.jpg

收拾好东西，赶快跑回家，心想别化完了，可就亏大了。
到了家，拿了2块开始和同伴分享。
Haagen-Dazs1.jpg

一块黑的:
Haagen-Dazs3.jpg

一块白的:
Haagen-Dazs2.jpg

我一口吃了半个白的
Haagen-Dazs4.jpg

再一口吃了半个黑的。
回味了半天，怎么还不如我的千层雪好吃:(

剩了两块，是留给桔子的，希望她喜欢就好了。

Posted by eygle at 10:37 PM | Comments (25)

Oracle10gR2 New Feature:V$SESSION change tracking

作者:eygle

出处:http://blog.eygle.com

从Oracle10g开始，伴随ASH功能的引入，Oracle对V$SESSION视图进行了彻底改造。
关于V$SESSION在几个版本中结构变化可以参考:Oracle数据字典说明

从Oracle10gR1开始，Oracle在V$SESSION中增加关于等待事件的字段，实际上也就是把原来V$SESSION_WAIT视图中的所有字段全部整合到了V$SESSION视图中，开始的时候我还以为ASH是依赖联合查询来获取信息的，仔细一看才发现现在V$SESSION已经发生了变化。(如果进一步研究你会发现，实际上V$SESSION的底层查询语句及X$表已经有了变化)

这一变化使得我们的查询得以简化，但是也使得V$SESSION_WAIT开始变得多余。
此外V$SESSION中还增加了BLOCKING_SESSION等字段，以前我们需要通过dba_waiters等视图才能获得的信息，现在也可以直接从V$SESSION中得到了。

在Oracle10gR2中，Oracle又为V$SESSION增加了额外几个字段：
SERVICE_NAME                                                     
SQL_TRACE 
SQL_TRACE_WAITS 
SQL_TRACE_BINDS

这几个字段又显示当前session连接方式及是否启用sql_trace等
我们看到Oracle在小处动的手脚是非常多的，而无疑这些小手脚会给我们的管理维护带来极大的方便。

以下是Oracle10gR2种v$session和v$session_wait两个view的结构供参考:
SQL> desc v$session
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 SADDR                                              RAW(4)
 SID                                                NUMBER
 SERIAL#                                            NUMBER
 AUDSID                                             NUMBER
 PADDR                                              RAW(4)
 USER#                                              NUMBER
 USERNAME                                           VARCHAR2(30)
 COMMAND                                            NUMBER
 OWNERID                                            NUMBER
 TADDR                                              VARCHAR2(8)
 LOCKWAIT                                           VARCHAR2(8)
 STATUS                                             VARCHAR2(8)
 SERVER                                             VARCHAR2(9)
 SCHEMA#                                            NUMBER
 SCHEMANAME                                         VARCHAR2(30)
 OSUSER                                             VARCHAR2(30)
 PROCESS                                            VARCHAR2(12)
 MACHINE                                            VARCHAR2(64)
 TERMINAL                                           VARCHAR2(30)
 PROGRAM                                            VARCHAR2(48)
 TYPE                                               VARCHAR2(10)
 SQL_ADDRESS                                        RAW(4)
 SQL_HASH_VALUE                                     NUMBER
 SQL_ID                                             VARCHAR2(13)
 SQL_CHILD_NUMBER                                   NUMBER
 PREV_SQL_ADDR                                      RAW(4)
 PREV_HASH_VALUE                                    NUMBER
 PREV_SQL_ID                                        VARCHAR2(13)
 PREV_CHILD_NUMBER                                  NUMBER
 MODULE                                             VARCHAR2(48)
 MODULE_HASH                                        NUMBER
 ACTION                                             VARCHAR2(32)
 ACTION_HASH                                        NUMBER
 CLIENT_INFO                                        VARCHAR2(64)
 FIXED_TABLE_SEQUENCE                               NUMBER
 ROW_WAIT_OBJ#                                      NUMBER
 ROW_WAIT_FILE#                                     NUMBER
 ROW_WAIT_BLOCK#                                    NUMBER
 ROW_WAIT_ROW#                                      NUMBER
 LOGON_TIME                                         DATE
 LAST_CALL_ET                                       NUMBER
 PDML_ENABLED                                       VARCHAR2(3)
 FAILOVER_TYPE                                      VARCHAR2(13)
 FAILOVER_METHOD                                    VARCHAR2(10)
 FAILED_OVER                                        VARCHAR2(3)
 RESOURCE_CONSUMER_GROUP                            VARCHAR2(32)
 PDML_STATUS                                        VARCHAR2(8)
 PDDL_STATUS                                        VARCHAR2(8)
 PQ_STATUS                                          VARCHAR2(8)
 CURRENT_QUEUE_DURATION                             NUMBER
 CLIENT_IDENTIFIER                                  VARCHAR2(64)
 BLOCKING_SESSION_STATUS                            VARCHAR2(11)
 BLOCKING_INSTANCE                                  NUMBER
 BLOCKING_SESSION                                   NUMBER
 SEQ#                                               NUMBER
 EVENT#                                             NUMBER
 EVENT                                              VARCHAR2(64)
 P1TEXT                                             VARCHAR2(64)
 P1                                                 NUMBER
 P1RAW                                              RAW(4)
 P2TEXT                                             VARCHAR2(64)
 P2                                                 NUMBER
 P2RAW                                              RAW(4)
 P3TEXT                                             VARCHAR2(64)
 P3                                                 NUMBER
 P3RAW                                              RAW(4)
 WAIT_CLASS_ID                                      NUMBER
 WAIT_CLASS#                                        NUMBER
 WAIT_CLASS                                         VARCHAR2(64)
 WAIT_TIME                                          NUMBER
 SECONDS_IN_WAIT                                    NUMBER
 STATE                                              VARCHAR2(19)
 SERVICE_NAME                                       VARCHAR2(64)
 SQL_TRACE                                          VARCHAR2(8)
 SQL_TRACE_WAITS                                    VARCHAR2(5)
 SQL_TRACE_BINDS                                    VARCHAR2(5)

SQL> desc v$session_wait
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 SID                                                NUMBER
 SEQ#                                               NUMBER
 EVENT                                              VARCHAR2(64)
 P1TEXT                                             VARCHAR2(64)
 P1                                                 NUMBER
 P1RAW                                              RAW(4)
 P2TEXT                                             VARCHAR2(64)
 P2                                                 NUMBER
 P2RAW                                              RAW(4)
 P3TEXT                                             VARCHAR2(64)
 P3                                                 NUMBER
 P3RAW                                              RAW(4)
 WAIT_CLASS_ID                                      NUMBER
 WAIT_CLASS#                                        NUMBER
 WAIT_CLASS                                         VARCHAR2(64)
 WAIT_TIME                                          NUMBER
 SECONDS_IN_WAIT                                    NUMBER
 STATE                                              VARCHAR2(19)

SQL>

Posted by eygle at 11:55 AM | Comments (0)

Oracle数据字典说明

作者:eygle

出处:http://blog.eygle.com

逐渐整理记录Oracle数据字典表的创建、内容及含义。 是自己学习的一个过程，权当记录，给自己参考。
View_Name Meanings Come from
GV$ENQUEUE_LOCK This view displays all locks owned by enqueue state objects. 
SELECT /*+ ORDERED USE_NL(L), USE_NL(S), USE_NL(R) +*/
            s.inst_id, l.addr, l.ksqlkadr, s.ksusenum, r.ksqrsidt, r.ksqrsid1,
            r.k sqrsid2, l.ksqlkmod, l.ksqlkreq, l.ksqlkctim, l.ksqlklblk
            FROM x$ksqeq l, x$ksuse s, x$ksqrs r
            WHERE l.ksqlkses = s.addr
            AND BITAND (l.kssobflg, 1) != 0
            AND (l.ksqlkmod != 0 OR l.ksqlkreq != 0)
            AND l.ksqlkres = r.addr
GV$PARAMETER Displays information about the initialization parameters. 
SELECT x.inst_id, x.indx + 1, ksppinm, ksppity, ksppstvl, ksppstdf,
            DECODE (BITAND (ksppiflg / 256, 1), 1, 'TRUE', 'FALSE'),
            DECODE (BITAND (ksppiflg / 65536, 3),
            1, 'IMMEDIATE',
            2, 'DEFERRED',
            3, 'IMMEDIATE',
            'FALSE'
            ),
            DECODE (BITAND (ksppstvf, 7), 1, 'MODIFIED', 4, 'SYSTEM_MOD', 'FALSE'),
            DECODE (BITAND (ksppstvf, 2), 2, 'TRUE', 'FALSE'), ksppdesc,
            ksppstcmnt
            FROM x$ksppi x, x$ksppcv y
            WHERE (x.indx = y.indx)
            AND ((TRANSLATE (ksppinm, '_', '#') NOT LIKE '#%') OR (ksppstdf = 'FALSE')
            )
GV$RESOURCE_LIMIT Global resource use for some of the system resources 
SELECT inst_id, ksurlmnm, ksurlmcv, ksurlmmv,
            LPAD (DECODE (BITAND (ksurlmfg, 1),
            0, TO_CHAR (ksurlmia),
            'UNLIMITED'
            ),
            10
            ),
            LPAD (DECODE (BITAND (ksurlmfg, 2),
            0, TO_CHAR (ksurlmlv),
            'UNLIMITED'
            ),
            10
            )
            FROM x$ksurlmt
GV$SEGSTAT Displays information about segment-level statistics 
select inst_id,
            fts_tsn,
            fts_objn,
            fts_objd,
            fts_statnam,
            fts_statid,
            fts_staval
            from x$ksolsfts
            where fts_inte = 0
GV$SESSION (Oracle9iR2 Version) Lists session information for each current session. 
SELECT inst_id, addr, indx, ksuseser, ksuudses, ksusepro, ksuudlui, ksuudlna,
            ksuudoct, ksusesow, DECODE (ksusetrn, HEXTORAW ('00'), NULL, ksusetrn),
            DECODE (ksqpswat, HEXTORAW ('00'), NULL, ksqpswat),
            DECODE (BITAND (ksuseidl, 11),
            1, 'ACTIVE',
            0, DECODE (BITAND (ksuseflg, 4096), 0, 'INACTIVE', 'CACHED'),
            2, 'SNIPED',
            3, 'SNIPED',
            'KILLED'
            ),
            DECODE (ksspatyp, 1, 'DEDICATED', 2, 'SHARED', 3, 'PSEUDO', 'NONE'),
            ksuudsid, ksuudsna, ksuseunm, ksusepid, ksusemnm, ksusetid, ksusepnm,
            DECODE (BITAND (ksuseflg, 19),
            17, 'BACKGROUND',
            1, 'USER',
            2, 'RECURSIVE',
            '?'
            ),
            ksusesql, ksusesqh, ksusepsq, ksusepha, ksuseapp, ksuseaph, ksuseact,
            ksuseach, ksusecli, ksusefix, ksuseobj, ksusefil, ksuseblk, ksuseslt,
            ksuseltm, ksusectm, DECODE (BITAND (ksusepfl, 16), 0, 'NO', 'YES'),
            DECODE (ksuseft,
            2, 'SESSION',
            4, 'SELECT',
            8, 'TRANSACTIONAL',
            'NONE'
            ),
            DECODE (ksusefm, 1, 'BASIC', 2, 'PRECONNECT', 4, 'PREPARSE', 'NONE'),
            DECODE (ksusefs, 1, 'YES', 'NO'), ksusegrp,
            DECODE (BITAND (ksusepfl, 16),
            16, 'ENABLED',
            DECODE (BITAND (ksusepfl, 32), 32, 'FORCED', 'DISABLED')
            ),
            DECODE (BITAND (ksusepfl, 64),
            64, 'FORCED',
            DECODE (BITAND (ksusepfl, 128), 128, 'DISABLED', 'ENABLED')
            ),
            DECODE (BITAND (ksusepfl, 512),
            512, 'FORCED',
            DECODE (BITAND (ksusepfl, 256), 256, 'DISABLED', 'ENABLED')
            ),
            ksusecqd, ksuseclid
            FROM x$ksuse
            WHERE BITAND (ksspaflg, 1) != 0 AND BITAND (ksuseflg, 1) != 0
GV$SESSION (Oracle10gR1 Version) Lists session information for each current session. 
SELECT s.inst_id, s.addr, s.indx, s.ksuseser, s.ksuudses, s.ksusepro,
            s.ksuudlui, s.ksuudlna, s.ksuudoct, s.ksusesow,
            DECODE (s.ksusetrn, HEXTORAW ('00'), NULL, s.ksusetrn),
            DECODE (s.ksqpswat, HEXTORAW ('00'), NULL, s.ksqpswat),
            DECODE (BITAND (s.ksuseidl, 11),
            1, 'ACTIVE',
            0, DECODE (BITAND (s.ksuseflg, 4096), 0, 'INACTIVE', 'CACHED'),
            2, 'SNIPED',
            3, 'SNIPED',
            'KILLED'
            ),
            DECODE (s.ksspatyp, 1, 'DEDICATED', 2, 'SHARED', 3, 'PSEUDO', 'NONE'),
            s.ksuudsid, s.ksuudsna, s.ksuseunm, s.ksusepid, s.ksusemnm, s.ksusetid,
            s.ksusepnm,
            DECODE (BITAND (s.ksuseflg, 19),
            17, 'BACKGROUND',
            1, 'USER',
            2, 'RECURSIVE',
            '?'
            ),
            s.ksusesql, s.ksusesqh, s.ksusesqi,
            DECODE (s.ksusesch, 65535, TO_NUMBER (NULL), s.ksusesch), s.ksusepsq,
            s.ksusepha, s.ksusepsi,
            DECODE (s.ksusepch, 65535, TO_NUMBER (NULL), s.ksusepch), s.ksuseapp,
            s.ksuseaph, s.ksuseact, s.ksuseach, s.ksusecli, s.ksusefix, s.ksuseobj,
            s.ksusefil, s.ksuseblk, s.ksuseslt, s.ksuseltm, s.ksusectm,
            DECODE (BITAND (s.ksusepxopt, 12), 0, 'NO', 'YES'),
            DECODE (s.ksuseft,
            2, 'SESSION',
            4, 'SELECT',
            8, 'TRANSACTIONAL',
            'NONE'
            ),
            DECODE (s.ksusefm, 1, 'BASIC', 2, 'PRECONNECT', 4, 'PREPARSE', 'NONE'),
            DECODE (s.ksusefs, 1, 'YES', 'NO'), s.ksusegrp,
            DECODE (BITAND (s.ksusepxopt, 4),
            4, 'ENABLED',
            DECODE (BITAND (s.ksusepxopt, 8), 8, 'FORCED', 'DISABLED')
            ),
            DECODE (BITAND (s.ksusepxopt, 2),
            2, 'FORCED',
            DECODE (BITAND (s.ksusepxopt, 1), 1, 'DISABLED', 'ENABLED')
            ),
            DECODE (BITAND (s.ksusepxopt, 32),
            32, 'FORCED',
            DECODE (BITAND (s.ksusepxopt, 16), 16, 'DISABLED', 'ENABLED')
            ),
            s.ksusecqd, s.ksuseclid,
            DECODE (s.ksuseblocker,
            4294967295, 'UNKNOWN',
            4294967294, 'GLOBAL',
            4294967293, 'UNKNOWN',
            4294967292, 'NO HOLDER',
            4294967291, 'NOT IN WAIT',
            'VALID'
            ),
            DECODE (s.ksuseblocker,
            4294967295, TO_NUMBER (NULL),
            4294967294, TO_NUMBER (NULL),
            4294967293, TO_NUMBER (NULL),
            4294967292, TO_NUMBER (NULL),
            4294967291, TO_NUMBER (NULL),
            s.ksuseblocker
            ),
            s.ksuseseq, s.ksuseopc, e.kslednam, e.ksledp1, s.ksusep1, s.ksusep1r,
            e.ksledp2, s.ksusep2, s.ksusep2r, e.ksledp3, s.ksusep3, s.ksusep3r,
            e.ksledclassid, e.ksledclass#, e.ksledclass,
            DECODE (s.ksusetim,
            0, 0,
            -1, -1,
            -2, -2,
            DECODE (ROUND (s.ksusetim / 10000),
            0, -1,
            ROUND (s.ksusetim / 10000)
            )
            ),
            s.ksusewtm,
            DECODE (s.ksusetim,
            0, 'WAITING',
            -2, 'WAITED UNKNOWN TIME',
            -1, 'WAITED SHORT TIME',
            DECODE (ROUND (s.ksusetim / 10000),
            0, 'WAITED SHORT TIME',
            'WAITED KNOWN TIME'
            )
            ),
            s.ksusesvc
            FROM x$ksuse s, x$ksled e
            WHERE BITAND (s.ksspaflg, 1) != 0
            AND BITAND (s.ksuseflg, 1) != 0
            AND s.ksuseopc = e.indx
GV$SESSION (Oracle10gR2 Version) Lists session information for each current session. 
SELECT s.inst_id, s.addr, s.indx, s.ksuseser, s.ksuudses, s.ksusepro,
            s.ksuudlui, s.ksuudlna, s.ksuudoct, s.ksusesow,
            DECODE (s.ksusetrn, HEXTORAW ('00'), NULL, s.ksusetrn),
            DECODE (s.ksqpswat, HEXTORAW ('00'), NULL, s.ksqpswat),
            DECODE (BITAND (s.ksuseidl, 11),
            1, 'ACTIVE',
            0, DECODE (BITAND (s.ksuseflg, 4096), 0, 'INACTIVE', 'CACHED'),
            2, 'SNIPED',
            3, 'SNIPED',
            'KILLED'
            ),
            DECODE (s.ksspatyp, 1, 'DEDICATED', 2, 'SHARED', 3, 'PSEUDO', 'NONE'),
            s.ksuudsid, s.ksuudsna, s.ksuseunm, s.ksusepid, s.ksusemnm, s.ksusetid,
            s.ksusepnm,
            DECODE (BITAND (s.ksuseflg, 19),
            17, 'BACKGROUND',
            1, 'USER',
            2, 'RECURSIVE',
            '?'
            ),
            s.ksusesql, s.ksusesqh, s.ksusesqi,
            DECODE (s.ksusesch, 65535, TO_NUMBER (NULL), s.ksusesch), s.ksusepsq,
            s.ksusepha, s.ksusepsi,
            DECODE (s.ksusepch, 65535, TO_NUMBER (NULL), s.ksusepch), s.ksuseapp,
            s.ksuseaph, s.ksuseact, s.ksuseach, s.ksusecli, s.ksusefix, s.ksuseobj,
            s.ksusefil, s.ksuseblk, s.ksuseslt, s.ksuseltm, s.ksusectm,
            DECODE (BITAND (s.ksusepxopt, 12), 0, 'NO', 'YES'),
            DECODE (s.ksuseft,
            2, 'SESSION',
            4, 'SELECT',
            8, 'TRANSACTIONAL',
            'NONE'
            ),
            DECODE (s.ksusefm, 1, 'BASIC', 2, 'PRECONNECT', 4, 'PREPARSE', 'NONE'),
            DECODE (s.ksusefs, 1, 'YES', 'NO'), s.ksusegrp,
            DECODE (BITAND (s.ksusepxopt, 4),
            4, 'ENABLED',
            DECODE (BITAND (s.ksusepxopt, 8), 8, 'FORCED', 'DISABLED')
            ),
            DECODE (BITAND (s.ksusepxopt, 2),
            2, 'FORCED',
            DECODE (BITAND (s.ksusepxopt, 1), 1, 'DISABLED', 'ENABLED')
            ),
            DECODE (BITAND (s.ksusepxopt, 32),
            32, 'FORCED',
            DECODE (BITAND (s.ksusepxopt, 16), 16, 'DISABLED', 'ENABLED')
            ),
            s.ksusecqd, s.ksuseclid,
            DECODE (s.ksuseblocker,
            4294967295, 'UNKNOWN',
            4294967294, 'UNKNOWN',
            4294967293, 'UNKNOWN',
            4294967292, 'NO HOLDER',
            4294967291, 'NOT IN WAIT',
            'VALID'
            ),
            DECODE (s.ksuseblocker,
            4294967295, TO_NUMBER (NULL),
            4294967294, TO_NUMBER (NULL),
            4294967293, TO_NUMBER (NULL),
            4294967292, TO_NUMBER (NULL),
            4294967291, TO_NUMBER (NULL),
            BITAND (s.ksuseblocker, 2147418112) / 65536
            ),
            DECODE (s.ksuseblocker,
            4294967295, TO_NUMBER (NULL),
            4294967294, TO_NUMBER (NULL),
            4294967293, TO_NUMBER (NULL),
            4294967292, TO_NUMBER (NULL),
            4294967291, TO_NUMBER (NULL),
            BITAND (s.ksuseblocker, 65535)
            ),
            s.ksuseseq, s.ksuseopc, e.kslednam, e.ksledp1, s.ksusep1, s.ksusep1r,
            e.ksledp2, s.ksusep2, s.ksusep2r, e.ksledp3, s.ksusep3, s.ksusep3r,
            e.ksledclassid, e.ksledclass#, e.ksledclass,
            DECODE (s.ksusetim,
            0, 0,
            -1, -1,
            -2, -2,
            DECODE (ROUND (s.ksusetim / 10000),
            0, -1,
            ROUND (s.ksusetim / 10000)
            )
            ),
            s.ksusewtm,
            DECODE (s.ksusetim,
            0, 'WAITING',
            -2, 'WAITED UNKNOWN TIME',
            -1, 'WAITED SHORT TIME',
            DECODE (ROUND (s.ksusetim / 10000),
            0, 'WAITED SHORT TIME',
            'WAITED KNOWN TIME'
            )
            ),
            s.ksusesvc,
            DECODE (BITAND (s.ksuseflg2, 32), 32, 'ENABLED', 'DISABLED'),
            DECODE (BITAND (s.ksuseflg2, 64), 64, 'TRUE', 'FALSE'),
            DECODE (BITAND (s.ksuseflg2, 128), 128, 'TRUE', 'FALSE')
            FROM x$ksuse s, x$ksled e
            WHERE BITAND (s.ksspaflg, 1) != 0
            AND BITAND (s.ksuseflg, 1) != 0
            AND s.ksuseopc = e.indx
GV$SQL Lists statistics on shared SQL area without the GROUP BY clause and contains one row for each child of the original SQL text entered. 
SELECT inst_id, kglnaobj,
            kglobhs0
            + kglobhs1
            + kglobhs2
            + kglobhs3
            + kglobhs4
            + kglobhs5
            + kglobhs6
            + kglobt16,
            kglobt08 + kglobt11, kglobt10, kglobt01, DECODE (kglobhs6, 0, 0, 1),
            DECODE (kglhdlmd, 0, 0, 1), kglhdlkc, kglobt04, kglobt05, kglobpc6,
            kglhdldc, SUBSTR (TO_CHAR (kglnatim, 'YYYY-MM-DD/HH24:MI:SS'), 1, 19),
            kglhdivc, kglobt12, kglobt13, kglobt14, kglobt15, kglobt02,
            DECODE (kglobt32,
            0, 'NONE',
            1, 'ALL_ROWS',
            2, 'FIRST_ROWS',
            3, 'RULE',
            4, 'CHOOSE',
            'UNKNOWN'
            ),
            kglobtn0, kglobt17, kglobt18, kglhdkmk, kglhdpar, kglobtp0, kglnahsh,
            kglobt30, kglobt09, kglobts0, kglobt19, kglobts1, kglobt20, kglobt21,
            kglobts2, kglobt06, kglobt07, kglobt28, kglhdadr, kglobt29,
            DECODE (BITAND (kglobt00, 64), 64, 'Y', 'N'),
            DECODE (kglobsta,
            1, 'VALID',
            2, 'VALID_AUTH_ERROR',
            3, 'VALID_COMPILE_ERROR',
            4, 'VALID_UNAUTH',
            5, 'INVALID_UNAUTH',
            6, 'INVALID'
            ),
            kglobt31, SUBSTR (TO_CHAR (kglobtt0, 'YYYY-MM-DD/HH24:MI:SS'), 1, 19),
            DECODE (kglobt33, 1, 'Y', 'N'), kglhdclt
            FROM x$kglcursor
            WHERE kglhdadr != kglhdpar AND kglobt02 != 0
GV$SQLAREA Lists statistics on shared SQL area and contains one row per SQL string. It provides statistics on SQL statements that are in memory, parsed, and ready for execution. . 
SELECT   inst_id, kglnaobj,
            SUM (  kglobhs0
            + kglobhs1
            + kglobhs2
            + kglobhs3
            + kglobhs4
            + kglobhs5
            + kglobhs6
            ),
            SUM (kglobt08 + kglobt11), SUM (kglobt10), SUM (kglobt01),
            COUNT (*) - 1, SUM (DECODE (kglobhs6, 0, 0, 1)),
            DECODE (SUM (DECODE (kglhdlmd, 0, 0, 1)),
            0, 0,
            SUM (DECODE (kglhdlmd, 0, 0, 1)) - 1
            ),
            SUM (kglhdlkc) / 2, SUM (kglobt04), SUM (kglobt05), SUM (kglobpc6),
            SUM (kglhdldc) - 1,
            SUBSTR (TO_CHAR (kglnatim, 'YYYY-MM-DD/HH24:MI:SS'), 1, 19),
            SUM (kglhdivc), SUM (kglobt12), SUM (kglobt13), SUM (kglobt14),
            SUM (kglobt15), SUM (DECODE (kglobt09, 0, kglobt02, 0)),
            DECODE (COUNT (*) - 1,
            1, DECODE (SUM (DECODE (kglobt09, 0, kglobt32, 0)),
            0, 'NONE',
            1, 'ALL_ROWS',
            2, 'FIRST_ROWS',
            3, 'RULE',
            4, 'CHOOSE',
            'UNKNOWN'
            ),
            'MULTIPLE CHILDREN PRESENT'
            ),
            SUM (DECODE (kglobt09, 0, kglobt17, 0)),
            SUM (DECODE (kglobt09, 0, kglobt18, 0)),
            DECODE (SUM (DECODE (kglhdkmk, 0, 0, 1)),
            0, 0,
            SUM (DECODE (kglhdkmk, 0, 0, 1)) - 1
            ),
            kglhdpar, kglnahsh, kglobts0, kglobt19, kglobts1, kglobt20,
            SUM (kglobt21), SUM (kglobt06), SUM (kglobt07),
            DECODE (kglobt33, 1, 'Y', 'N'), kglhdclt
            FROM x$kglcursor
            GROUP BY inst_id,
            kglnaobj,
            kglhdpar,
            kglnahsh,
            kglnatim,
            kglobts0,
            kglobt19,
            kglobts1,
            kglobt20,
            DECODE (kglobt33, 1, 'Y', 'N'),
            kglhdclt
            HAVING SUM (DECODE (kglobt09, 0, kglobt02, 0)) != 0

Posted by eygle at 9:27 AM | Comments (4)

Oracle10gR2 autotrace function was changed and enhanced

作者:eygle

出处:http://blog.eygle.com

今天在测试过程中，偶然发现在Oracle10g Release 2中，Autotrace的功能已经被极大加强和改变。
这是一个很有意思的小的变化，关于autotrace的使用，请参考:启用AutoTrace
接下来让我们先来看一下什么地方发生了改变: 
SQL> set linesize 120
SQL> set autotrace on
SQL> select count(*) from v$session
  2  /

  COUNT(*)
----------
        21


Execution Plan
----------------------------------------------------------
Plan hash value: 2376410614

---------------------------------------------------------------------------------------------
| Id  | Operation                 | Name            | Rows  | Bytes | Cost (%CPU)| Time     |
---------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT          |                 |     1 |    65 |     0   (0)| 00:00:01 |
|   1 |  SORT AGGREGATE           |                 |     1 |    65 |            |          |
|   2 |   NESTED LOOPS            |                 |     1 |    65 |     0   (0)| 00:00:01 |
|*  3 |    FIXED TABLE FULL       | X$KSUSE         |     1 |    52 |     0   (0)| 00:00:01 |
|*  4 |    FIXED TABLE FIXED INDEX| X$KSLED (ind:2) |     1 |    13 |     0   (0)| 00:00:01 |
---------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   3 - filter("S"."INST_ID"=USERENV('INSTANCE') AND BITAND("S"."KSSPAFLG",1)<>0 AND
              BITAND("S"."KSUSEFLG",1)<>0)
   4 - filter("S"."KSUSEOPC"="E"."INDX")


Statistics
----------------------------------------------------------
          1  recursive calls
          0  db block gets
          0  consistent gets
          0  physical reads
          0  redo size
        411  bytes sent via SQL*Net to client
        385  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
          0  sorts (memory)
          0  sorts (disk)
          1  rows processed

注意，此时autotrace的输出被良好格式化，并给出关于执行计划部分的简要注释。
其实这里并没有带来新的东西，从Oracle9i开始，Oracle提供了一个新的工具dbms_xplan用以格式化和查看SQL的执行计划。其原理是通过对plan_table的查询和格式化提供更友好的用户输出。

dbms_xplan的调用的语法类似:
select * from table(dbms_xplan.display(format=>'BASIC'))
使用 TABLE() 操作符，或者 CAST 操作。

具体用法可以参考Oracle官方文档。

实际上从Oracle9i开始我们就经常使用如下方式调用dbms_xplan:
Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production

SQL> explain plan for
  2  select count(*) from dual;

Explained.

SQL> @?/rdbms/admin/utlxplp;

PLAN_TABLE_OUTPUT
----------------------------------------------------------------------------------

--------------------------------------------------------------------
| Id  | Operation            |  Name       | Rows  | Bytes | Cost  |
--------------------------------------------------------------------
|   0 | SELECT STATEMENT     |             |       |       |       |
|   1 |  SORT AGGREGATE      |             |       |       |       |
|   2 |   TABLE ACCESS FULL  | DUAL        |       |       |       |
--------------------------------------------------------------------

Note: rule based optimization

10 rows selected.

utlxplp.sql脚本中正是调用了dbms_xplan:
SQL> get ?/rdbms/admin/utlxplp;
  1  Rem
  2  Rem $Header: utlxplp.sql 23-jan-2002.08:55:23 bdagevil Exp $
  3  Rem
  4  Rem utlxplp.sql
  5  Rem
  6  Rem Copyright (c) 1998, 2002, Oracle Corporation.  All rights reserved.
  7  Rem
  8  Rem    NAME
  9  Rem      utlxplp.sql - UTiLity eXPLain Parallel plans
 10  Rem
 11  Rem    DESCRIPTION
 12  Rem      script utility to display the explain plan of the last explain plan
 13  Rem         command. Display also Parallel Query information if the plan happens to
 14  Rem      run parallel
 15  Rem
 16  Rem    NOTES
 17  Rem      Assume that the table PLAN_TABLE has been created. The script
 18  Rem      utlxplan.sql should be used to create that table
 19  Rem
 20  Rem      With SQL*plus, it is recomended to set linesize and pagesize before
 21  Rem      running this script. For example:
 22  Rem            set linesize 130
 23  Rem            set pagesize 0
 24  Rem
 25  Rem    MODIFIED   (MM/DD/YY)
 26  Rem    bdagevil    01/23/02 - rewrite with new dbms_xplan package
 27  Rem    bdagevil    04/05/01 - include CPU cost
 28  Rem    bdagevil    02/27/01 - increase Name column
 29  Rem    jihuang     06/14/00 - change order by to order siblings by.
 30  Rem    jihuang     05/10/00 - include plan info for recursive SQL in LE row source
 31  Rem    bdagevil    01/05/00 - make deterministic with order-by
 32  Rem    bdagevil    05/07/98 - Explain plan script for parallel plans
 33  Rem    bdagevil    05/07/98 - Created
 34  Rem
 35  set markup html preformat on
 36  Rem
 37  Rem Use the display table function from the dbms_xplan package to display the last
 38  Rem explain plan. Use default mode which will display only relevant information
 39  Rem
 40* select * from table(dbms_xplan.display());
 41  
SQL>

而在Oracle10gR2中，Oracle帮我们简化了这个过程，一个autotrace就完成了所有的输出，这也是易用性上的一个进步吧。在使用Oracle的过程中，我们经常能够感受到Oracle针对用户需求或易用性的改进，这也许是很多人喜爱Oracle的一个原因吧。

如果足够信息我们还会注意到，在Oracle10g中PLAN_TABLE不再需要创建，Oracle缺省增加了一个字典表PLAN_TABLE$，然后基于PLAN_TABLE$创建公用同义词供用户使用。

关于dbms_xplan工具的使用还可以参考Itpub上的讨论:使用dbms_xplan工具查看执行计划.

Posted by eygle at 12:35 AM | Comments (0)

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