Databases Reference
In-Depth Information
The output file is a trace file that contains the database calls and wait events of all processes
involved in the parallel execution. The combined trace file may be processed with TKPROF.
C:\oracle\admin\orcl\bdump> tkprof pqtest_1894.trc pqtest_1894.tkp
Whereas the trace file of the query coordinator reports zero disk reads as well as zero
consistent reads,
8
the combined formatted trace file gives an accurate account of the resource
consumption.
OVERALL TOTALS FOR ALL NON-RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
------- ------ -------- ---------- -------- -------- -------- ------
Parse 7 0.00 0.00 0 0 0 0
Execute 7 0.18 7.05 5209 5368 0 1
Fetch 4 0.01 1.87 0 0 0 2
------- ------ -------- ---------- -------- -------- -------- ------
total 18 0.20 8.93 5209 5368 0 3
Disk reads are due to direct path reads performed by the parallel execution processes,
which do not use the buffer cache in the SGA. Since parallel execution circumvents the buffer
cache, it benefits from caching at the file system level by the operating system.
8.
FETCH #2:c=15625,e=1875092,p=0,cr=0,cu=0,mis=0,r=1,dep=0,og=1,tim=108052435005
