Oracle 有关 Consistent gets 的测试
一．Consistentgets 说明
我们使用autotrace 查看执行计划和统计信息时，会显示类似如下信息：
0 recursive calls :递归调用。一般原因：dictionary cache未命中；动态存储扩展；PL/SQL语句
0 db block gets :bufer中读取的block数量，用于insert,update,delete,selectfor update
174530 consistent gets :这里是一致读次数（一个block可能会被读多次），bufer中读取的用于查询（除掉select forupdate）的block数量。
--db blocksgets+consistent gets= logical read
0 physical reads :从磁盘上读取的block数量
0 redo size :bytes，写到redo logs的数据量
3546854 bytes sent via SQL*Net to client
60244 bytes received via SQL*Net from client
5433 SQL*Net roundtrips to/from client
0 sorts (memory) :内存排序次数
0 sorts (disk) :磁盘排序次数；与sort_area_size有关
81467 rows processed
官网对consistent gets 的解释：
consistent gets：Number of times a consistent read wasrequested for a block.
通常我们执行SQL查询时涉及的每一block都是Consistent Read, 只是有些CR(Consistent Read)需要使用undo 来进行构造, 大部分CR(Consistent Read)并不涉及到undo block的读.
还有就是每次读这个block都是一次CR(可能每个block上有多个数据row), 也就是如果某个block被读了10次, 系统会记录10个Consistent Read.
简单的说：
consistentgets : 通过不带for update的select 读的blocks.
dbblock gets : 通过update/delete/selectfor update读的blocks.
db block gets + consistent gets = 整个逻辑读。
二．测试
2.1 测试环境
OS: Oracle linux 6.1
DB: Oracle 11.2.0.3
2.2 对比Consistent gets
SQL> select count(1) from dave;
COUNT(1)
----------
1164176
SQL> create index idx_dave_objid ondave(object_id);
Index created.
SQL> execdbms_stats.gather_table_stats('sys','dave',cascade=>true);
PL/SQL procedure successfully completed.
SQL> set tim on timing on
08:20:01 SQL> set autot trace exp stat;
08:20:16 SQL> select * from dave whereobject_id=10;
16 rows selected.
Elapsed: 00:00:00.13
Execution Plan
----------------------------------------------------------
Plan hash value: 3358514785
--------------------------------------------------------------------------------
--------------
| Id | Operation | Name | Rows | Bytes | Cost (%CP
U)| Time |
--------------------------------------------------------------------------------
--------------
| 0| SELECT STATEMENT | | 16 | 1552 | 19 (
0)| 00:00:01 |
| 1| TABLE ACCESS BY INDEX ROWID| DAVE | 16 | 1552 | 19 (
0)| 00:00:01 |
|* 2| INDEX RANGE SCAN | IDX_DAVE_OBJID | 16 | | 3 (
0)| 00:00:01 |
--------------------------------------------------------------------------------
--------------
Predicate Information (identified byoperation id):
---------------------------------------------------
2- access("OBJECT_ID"=10)
Statistics
----------------------------------------------------------
15 recursive calls
0 db block gets
63 consistent gets
0 physical reads
0 redo size
3043 bytes sent via SQL*Net toclient
534 bytes received via SQL*Netfrom client
3 SQL*Net roundtrips to/fromclient
0 sorts (memory)
0 sorts (disk)
16 rows processed
08:20:23 SQL> set lin 120
08:20:43 SQL> /
16 rows selected.
Elapsed: 00:00:00.02
Execution Plan
----------------------------------------------------------
Plan hash value: 3358514785
----------------------------------------------------------------------------------------------
| Id | Operation |Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 16 | 1552 | 19 (0)| 00:00:01 |
| 1| TABLE ACCESS BY INDEX ROWID| DAVE | 16 | 1552 | 19 (0)| 00:00:01 |
|* 2| INDEX RANGE SCAN | IDX_DAVE_OBJID | 16 | | 3 (0)| 00:00:01 |
----------------------------------------------------------------------------------------------
Predicate Information (identified by operationid):
---------------------------------------------------
2- access("OBJECT_ID"=10)
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
21 consistent gets
0 physical reads
0 redo size
3043 bytes sent via SQL*Net toclient
534 bytes received via SQL*Netfrom client
3 SQL*Net roundtrips to/fromclient
0 sorts (memory)
0 sorts (disk)
16 rows processed
相同的SQL，第一次执行产生了63次consistent gets，第二次执行产生了21次consistent gets，减少2/3.
2.3 使用10046 跟踪SQL
--在跟踪之前，为避免缓存带来的影响，我们先刷新shared pool 和 db buffer。
08:27:31 SQL> alter system flushshared_pool;
System altered.
Elapsed: 00:00:00.21
08:28:47 SQL> alter system flushbuffer_cache;
System altered.
Elapsed: 00:00:00.30
--使用10046 跟踪：
--第一次：
SQL> set tim on timing on
08:50:08 SQL> set autot trace stat
08:50:16 SQL> oradebug setmypid
Statement processed.
08:50:20 SQL> alter session set tracefile_identifier='dave1';
Session altered.
Elapsed: 00:00:00.01
08:50:26 SQL> oradebug event 10046 tracename context forever,level 12;
Statement processed.
08:50:31 SQL> select * from dave whereobject_id=10;
16 rows selected.
Elapsed: 00:00:00.07
Statistics
----------------------------------------------------------
40 recursive calls
0 db block gets
94 consistent gets
26 physical reads
0 redo size
1959 bytes sent via SQL*Net toclient
534 bytes received via SQL*Netfrom client
3 SQL*Net roundtrips to/fromclient
4 sorts (memory)
0 sorts (disk)
16 rows processed
08:50:36 SQL> oradebug event 10046 tracename context off;
Statement processed.
08:50:42 SQL> oradebug tracefile_name
/u01/app/oracle/diag/rdbms/dave/dave/trace/dave_ora_9774_dave1.trc
08:50:45 SQL>
--第二次：
08:50:45 SQL> alter session settracefile_identifier='dave2';
Session altered.
Elapsed: 00:00:00.01
08:51:34 SQL> oradebug event 10046 tracename context forever,level 12;
Statement processed.
08:51:40 SQL> select * from dave whereobject_id=10;
16 rows selected.
Elapsed: 00:00:00.01
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
21 consistent gets
0 physical reads
0 redo size
1959 bytes sent via SQL*Net toclient
534 bytes received via SQL*Netfrom client
3 SQL*Net roundtrips to/fromclient
0 sorts (memory)
0 sorts (disk)
16 rows processed
08:51:45 SQL> oradebug event 10046 tracename context off;
Statement processed.
08:51:52 SQL> oradebug tracefile_name
/u01/app/oracle/diag/rdbms/dave/dave/trace/dave_ora_9774_dave2.trc
第一次执行： 产生94个consistent gets，trace file：dave_ora_9774_dave1.trc
第二次执行： 产生21个consistentgets，trace file：dave_ora_9774_dave2.trc
2.4 使用tkprof 格式化trace file
1. 第一次的trace file：
[oracle@dave ~]$ tkprof /u01/app/oracle/diag/rdbms/dave/dave/trace/dave_ora_9774_dave1.trc/u01/dave1.trc
TKPROF: Release 11.2.0.3.0 - Development onWed Sep 12 08:56:59 2012
Copyright (c) 1982, 2011, Oracle and/or itsaffiliates. All rights reserved.
2. 第二次的trace file：
[oracle@dave ~]$ tkprof/u01/app/oracle/diag/rdbms/dave/dave/trace/dave_ora_9774_dave2.trc/u01/dave2.trc
TKPROF: Release 11.2.0.3.0 - Development onWed Sep 12 08:57:29 2012
Copyright (c) 1982, 2011, Oracle and/or itsaffiliates. All rights reserved.
2.5 对比tracefile
1. trace 1
OVERALLTOTALS FOR ALL NON-RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 1 0.01 0.02 7 73 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 3 0.00 0.00 19 21 0 16
------- ------ -------- ---------- ---------- -------------------- ----------
total 5 0.02 0.02 26 94 0 16
Misses in library cache during parse: 1
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 5 0.00 0.00
SQL*Net message from client 5 4.55 4.55
dbfile sequential read 5 0.00 0.00
dbfile parallel read 1 0.00 0.00
OVERALLTOTALS FOR ALL RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 22 0.00 0.00 0 0 0 0
Fetch 39 0.00 0.00 7 73 0 36
------- ------ -------- ---------- ---------- -------------------- ----------
total 61 0.00 0.01 7 73 0 36
Misses in library cache during parse: 0
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
dbfile sequential read 7 0.00 0.00
1 user SQL statements in session.
7 internal SQL statements insession.
8 SQL statements in session.
2. trace 2
OVERALLTOTALS FOR ALL NON-RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 1 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 3 0.00 0.00 0 21 0 16
------- ------ -------- ---------- ---------- -------------------- ----------
total 5 0.00 0.00 0 21 0 16
Misses in library cache during parse: 0
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 5 0.00 0.00
SQL*Net message from client 5 5.15 5.16
OVERALLTOTALS FOR ALL RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 0 0.00 0.00 0 0 0 0
Fetch 0 0.00 0.00 0 0 0 0
------- ------ -------- ---------- ---------- -------------------- ----------
total 0 0.00 0.00 0 0 0 0
Misses in library cache during parse: 0
1 user SQL statements in session.
0 internal SQL statements insession.
1 SQL statements in session.
以上关键部分已经黑体加粗。
3. 小结
NON-RECURSIVESTATEMENTS：
指非递归的SQL，就是用户本身SQL消耗的实际资源情况。
RECURSIVESTATEMENTS
指递归SQL，就是由用户SQL衍生出来的其他的SQL，这里通常指为了执行这条SQL语句，而对其进行语义分析，动态采样等操作。所以这部分的消耗是这些衍生SQL的消耗。
通过2个trace 对比，我们可以看出trace 1 比trace 2多出来的consistent gets就是用来parse的部分，其实际执行的消耗都是一样的。都是21.
在trace 1中，我们看到的解析产生的consistent get 是73. 其也是由很多部分组成，在开始的那部分信息，都是与解析相关。关于在解析的步骤和消耗，可以查看附录4.1 中完整的trace 。这里列一个计算结果：
8+4+7+3+3+3+45= 73.
三．总结
当我们第一次执行一条SQL语句时，Oracle 会其进行一个硬解析的操作，这个操作会额外的消耗一些资源，比如语法分析，语义分析，制定执行计划等操作。所以我们看到的consistent gets会比较大，第二次执行相同的SQL时，没有进行硬解析，所以产生的consistent gets就是我们SQL 实际的一个资源消耗。
四．附录：完整的TraceFile
4.1 dave1.trc
[oracle@dave u01]$ cat dave1.trc
TKPROF: Release 11.2.0.3.0 - Development onWed Sep 12 08:56:59 2012
Copyright (c) 1982, 2011, Oracle and/or itsaffiliates. All rights reserved.
Trace file:/u01/app/oracle/diag/rdbms/dave/dave/trace/dave_ora_9774_dave1.trc
Sort options: default
********************************************************************************
count = number of times OCI procedure was executed
cpu = cpu time in seconds executing
elapsed = elapsed time in seconds executing
disk = number of physical reads of buffers from disk
query = number of buffers gotten for consistent read
current = number of buffers gotten in current mode (usually for update)
rows = number of rows processed by the fetch or execute call
********************************************************************************
SQL ID: 3nkd3g3ju5ph1 Plan Hash: 2853959010
select obj#,type#,ctime,mtime,stime,status, dataobj#, flags, oid$, spare1,
spare2
from
obj$where owner#=:1 and name=:2 and namespace=:3 and remoteowner is null
andlinkname is null and subname is null
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 2 0.00 0.00 0 0 0 0
Fetch 2 0.00 0.00 1 8 0 2
------- ------ -------- ---------- ---------- -------------------- ----------
total 4 0.00 0.00 1 8 0 2
Misses in library cache during parse: 0
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
dbfile sequential read 1 0.00 0.00
********************************************************************************
SQL ID: 1gu8t96d0bdmu Plan Hash: 2035254952
selectt.ts#,t.file#,t.block#,nvl(t.bobj#,0),nvl(t.tab#,0),t.intcols,
nvl(t.clucols,0),t.audit$,t.flags,t.pctfree$,t.pctused$,t.initrans,
t.maxtrans,t.rowcnt,t.blkcnt,t.empcnt,t.avgspc,t.chncnt,t.avgrln,
t.analyzetime,t.samplesize,t.cols,t.property,nvl(t.degree,1),
nvl(t.instances,1),t.avgspc_flb,t.flbcnt,t.kernelcols,nvl(t.trigflag,0),
nvl(t.spare1,0),nvl(t.spare2,0),t.spare4,t.spare6,ts.cachedblk,ts.cachehit,
ts.logicalread
from
tab$t, tab_stats$ ts where t.obj#= :1 and t.obj# = ts.obj# (+)
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 1 0.00 0.00 2 4 0 1
------- ------ -------- ---------- ---------- -------------------- ----------
total 2 0.00 0.00 2 4 0 1
Misses in library cache during parse: 0
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
dbfile sequential read 2 0.00 0.00
********************************************************************************
SQL ID: 7ng34ruy5awxq Plan Hash: 3992920156
selecti.obj#,i.ts#,i.file#,i.block#,i.intcols,i.type#,i.flags,i.property,
i.pctfree$,i.initrans,i.maxtrans,i.blevel,i.leafcnt,i.distkey,i.lblkkey,
i.dblkkey,i.clufac,i.cols,i.analyzetime,i.samplesize,i.dataobj#,
nvl(i.degree,1),nvl(i.instances,1),i.rowcnt,mod(i.pctthres$,256),
i.indmethod#,i.trunccnt,nvl(c.unicols,0),nvl(c.deferrable#+c.valid#,0),
nvl(i.spare1,i.intcols),i.spare4,i.spare2,i.spare6,decode(i.pctthres$,null,
null,mod(trunc(i.pctthres$/256),256)),ist.cachedblk,ist.cachehit,
ist.logicalread
from
ind$i, ind_stats$ ist, (select enabled, min(cols) unicols,
min(to_number(bitand(defer,1)))deferrable#,min(to_number(bitand(defer,4)))
valid# from cdef$ where obj#=:1 and enabled > 1 group by enabled) cwhere
i.obj#=c.enabled(+) and i.obj# = ist.obj#(+) and i.bo#=:1 order by i.obj#
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 2 0.00 0.00 2 7 0 1
------- ------ -------- ---------- ---------- -------------------- ----------
total 3 0.00 0.00 2 7 0 1
Misses in library cache during parse: 0
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
dbfile sequential read 2 0.00 0.00
********************************************************************************
SQL ID: 5n1fs4m2n2y0r Plan Hash: 299250003
selectpos#,intcol#,col#,spare1,bo#,spare2,spare3
from
icol$ where obj#=:1
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 2 0.00 0.00 1 3 0 1
------- ------ -------- ---------- ---------- -------------------- ----------
total 3 0.00 0.00 1 3 0 1
Misses in library cache during parse: 0
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
dbfile sequential read 1 0.00 0.00
********************************************************************************
SQL ID: 83taa7kaw59c1 Plan Hash: 3765558045
select name,intcol#,segcol#,type#,length,nvl(precision#,0),decode(type#,2,
nvl(scale,-127/*MAXSB1MINAL*/),178,scale,179,scale,180,scale,181,scale,182,
scale,183,scale,231,scale,0),null$,fixedstorage,nvl(deflength,0),default$,
rowid,col#,property, nvl(charsetid,0),nvl(charsetform,0),spare1,spare2,
nvl(spare3,0)
from
col$where obj#=:1 order by intcol#
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 16 0.00 0.00 0 3 0 15
------- ------ -------- ---------- ---------- -------------------- ----------
total 17 0.00 0.00 0 3 0 15
Misses in library cache during parse: 0
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
********************************************************************************
SQL ID: 87gaftwrm2h68 Plan Hash: 1218588913
selecto.owner#,o.name,o.namespace,o.remoteowner,o.linkname,o.subname
from
obj$o where o.obj#=:1
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 1 0.00 0.00 0 3 0 1
------- ------ -------- ---------- ---------- -------------------- ----------
total 2 0.00 0.00 0 3 0 1
Misses in library cache during parse: 0
Optimizer mode: CHOOSE
Parsing user id: SYS (recursive depth: 1)
********************************************************************************
SQL ID: 96g93hntrzjtr Plan Hash: 2239883476
select /*+ rule */ bucket_cnt, row_cnt,cache_cnt, null_cnt, timestamp#,
sample_size, minimum, maximum, distcnt, lowval, hival, density, col#,
spare1, spare2, avgcln
from
hist_head$ where obj#=:1 and intcol#=:2
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 15 0.00 0.00 0 0 0 0
Fetch 15 0.00 0.00 1 45 0 15
------- ------ -------- ---------- ---------- -------------------- ----------
total 30 0.00 0.00 1 45 0 15
Misses in library cache during parse: 0
Optimizer mode: RULE
Parsing user id: SYS (recursive depth: 1)
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
dbfile sequential read 1 0.00 0.00
********************************************************************************
SQL ID: 6rsg9q38ak6ys Plan Hash: 3358514785
select *
from
davewhere object_id=10
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 1 0.01 0.02 7 73 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 3 0.00 0.00 19 21 0 16
------- ------ -------- ---------- ---------- -------------------- ----------
total 5 0.02 0.02 26 94 0 16
Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: SYS
Number of plan statistics captured: 1
Rows (1st) Rows (avg) Rows (max) Row Source Operation
---------- ---------- ---------- ---------------------------------------------------
16 16 16 TABLE ACCESS BY INDEX ROWID DAVE (cr=21 pr=19 pw=0 time=2502 us cost=19size=1552 card=16)
16 16 16 INDEX RANGE SCAN IDX_DAVE_OBJID (cr=5 pr=3 pw=0 time=1644 us cost=3size=0 card=16)(object id 76858)
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 3 0.00 0.00
dbfile sequential read 5 0.00 0.00
SQL*Net message from client 3 0.00 0.00
dbfile parallel read 1 0.00 0.00
********************************************************************************
OVERALL TOTALS FOR ALL NON-RECURSIVESTATEMENTS
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 1 0.01 0.02 7 73 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 3 0.00 0.00 19 21 0 16
------- ------ -------- ---------- ---------- -------------------- ----------
total 5 0.02 0.02 26 94 0 16
Misses in library cache during parse: 1
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 5 0.00 0.00
SQL*Net message from client 5 4.55 4.55
dbfile sequential read 5 0.00 0.00
dbfile parallel read 1 0.00 0.00
OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 22 0.00 0.00 0 0 0 0
Fetch 39 0.00 0.00 7 73 0 36
------- ------ -------- ---------- ---------- -------------------- ----------
total 61 0.00 0.01 7 73 0 36
Misses in library cache during parse: 0
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
dbfile sequential read 7 0.00 0.00
1 user SQL statements in session.
7 internal SQL statements insession.
8 SQL statements in session.
********************************************************************************
Trace file:/u01/app/oracle/diag/rdbms/dave/dave/trace/dave_ora_9774_dave1.trc
Trace file compatibility: 11.1.0.7
Sort options: default
4 sessions in tracefile.
2 user SQL statements in trace file.
14 internal SQL statements in tracefile.
8 SQL statements in trace file.
8 unique SQL statements in tracefile.
465 lines in trace file.
0 elapsed seconds in trace file.
4.2 dave2.trc
[oracle@dave u01]$ cat dave2.trc
TKPROF: Release 11.2.0.3.0 - Development onWed Sep 12 08:57:29 2012
Copyright (c) 1982, 2011, Oracle and/or itsaffiliates. All rights reserved.
Trace file:/u01/app/oracle/diag/rdbms/dave/dave/trace/dave_ora_9774_dave2.trc
Sort options: default
********************************************************************************
count = number of times OCI procedure was executed
cpu = cpu time in seconds executing
elapsed = elapsed time in seconds executing
disk = number of physical reads of buffers from disk
query = number of buffers gotten for consistent read
current = number of buffers gotten in current mode (usually for update)
rows = number of rows processed by the fetch or execute call
********************************************************************************
SQL ID: 6rsg9q38ak6ys Plan Hash: 3358514785
select *
from
davewhere object_id=10
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 1 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 3 0.00 0.00 0 21 0 16
------- ------ -------- ---------- ---------- -------------------- ----------
total 5 0.00 0.00 0 21 0 16
Misses in library cache during parse: 0
Optimizer mode: ALL_ROWS
Parsing user id: SYS
Number of plan statistics captured: 1
Rows (1st) Rows (avg) Rows (max) Row Source Operation
---------- ---------- ---------- ---------------------------------------------------
16 16 16 TABLE ACCESS BY INDEX ROWID DAVE (cr=21 pr=0 pw=0 time=963 us cost=19size=1552 card=16)
16 16 16 INDEX RANGE SCAN IDX_DAVE_OBJID (cr=5 pr=0 pw=0 time=671 us cost=3 size=0card=16)(object id 76858)
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 3 0.00 0.00
SQL*Net message from client 3 0.00 0.00
********************************************************************************
OVERALL TOTALS FOR ALL NON-RECURSIVESTATEMENTS
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 1 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 3 0.00 0.00 0 21 0 16
------- ------ -------- ---------- ---------- -------------------- ----------
total 5 0.00 0.00 0 21 0 16
Misses in library cache during parse: 0
Elapsed times include waiting on followingevents:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 5 0.00 0.00
SQL*Net message from client 5 5.15 5.16
OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- -------------------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 0 0.00 0.00 0 0 0 0
Fetch 0 0.00 0.00 0 0 0 0
------- ------ -------- ---------- ---------- -------------------- ----------
total 0 0.00 0.00 0 0 0 0
Misses in library cache during parse: 0
1 user SQL statements in session.
0 internal SQL statements insession.
1 SQL statements in session.
********************************************************************************
Trace file:/u01/app/oracle/diag/rdbms/dave/dave/trace/dave_ora_9774_dave2.trc
Trace file compatibility: 11.1.0.7
Sort options: default
5 sessions in tracefile.
2 user SQL statements in trace file.
0 internal SQL statements intrace file.
1 SQL statements in trace file.
1 unique SQL statements in tracefile.
120 lines in trace file.
0 elapsed seconds in trace file.
-------------------------------------------------------------------------------------------------------
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