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11#
发表于 2013-3-3 23:44:34
谢谢ML的分享以及抛玉引砖 ~
我简单补充一下,这个部分的缩写其实可以从Oracle的10053 trace文件中方便查到,如果看10053 trace 多了,应该就比较熟悉啦 :)- [oracle@stonedb trace]$ sqlplus / as sysdba
- SQL*Plus: Release 11.2.0.3.0 Production on Sun Mar 3 23:20:52 2013
- Copyright (c) 1982, 2011, Oracle. All rights reserved.
- Connected to:
- Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - Production
- With the Partitioning, OLAP, Data Mining and Real Application Testing options
- SQL> ALTER SESSION SET EVENTS '10053 trace name context forever, level 1';
- Session altered.
- SQL> select count(*) from dba_objects;
- COUNT(*)
- ----------
- 74551
- SQL> ALTER SESSION SET EVENTS '10053 trace name context off';
- Session altered.
- SQL>
- SQL> !pwd
- /u01/app/oracle/diag/rdbms/stone11g/STONE11G/trace
- SQL> !ls -lrth | tail -2
- -rw-rw---- 1 oracle oinstall 71K Mar 3 23:22 STONE11G_ora_7155.trm
- -rw-rw---- 1 oracle oinstall 267K Mar 3 23:22 STONE11G_ora_7155.trc
复制代码 Legend位于10053 trace文件的大概位置:- [oracle@stonedb trace]$ grep -i legend -A 52 STONE11G_ora_7155.trc
- Legend
- The following abbreviations are used by optimizer trace.
- CBQT - cost-based query transformation
- JPPD - join predicate push-down
- OJPPD - old-style (non-cost-based) JPPD
- FPD - filter push-down
- PM - predicate move-around
- CVM - complex view merging
- SPJ - select-project-join
- SJC - set join conversion
- SU - subquery unnesting
- OBYE - order by elimination
- OST - old style star transformation
- ST - new (cbqt) star transformation
- CNT - count(col) to count(*) transformation
- JE - Join Elimination
- JF - join factorization
- SLP - select list pruning
- DP - distinct placement
- qb - query block
- LB - leaf blocks
- DK - distinct keys
- LB/K - average number of leaf blocks per key
- DB/K - average number of data blocks per key
- CLUF - clustering factor
- NDV - number of distinct values
- Resp - response cost
- Card - cardinality
- Resc - resource cost
- NL - nested loops (join)
- SM - sort merge (join)
- HA - hash (join)
- CPUSPEED - CPU Speed
- IOTFRSPEED - I/O transfer speed
- IOSEEKTIM - I/O seek time
- SREADTIM - average single block read time
- MREADTIM - average multiblock read time
- MBRC - average multiblock read count
- MAXTHR - maximum I/O system throughput
- SLAVETHR - average slave I/O throughput
- dmeth - distribution method
- 1: no partitioning required
- 2: value partitioned
- 4: right is random (round-robin)
- 128: left is random (round-robin)
- 8: broadcast right and partition left
- 16: broadcast left and partition right
- 32: partition left using partitioning of right
- 64: partition right using partitioning of left
- 256: run the join in serial
- 0: invalid distribution method
- sel - selectivity
- ptn - partition
复制代码 |
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