Read the results shown in the trace files

Question

Hi,
I have a question,
In oracle 10g or 11g, How can I interpret the results shown in the trace files?
ok I explain more ... when I enable the trace sql session , a trace file is created under user dump!
What 's the meaning of :
*1- PARSING IN CURSOR*
*2- tim= is it in Microseconds? Timestamp ? How can I convert it in seconds?*
*3- STAT*
*4- CLOSE*
*5- hv=*
*6- tim=*
*7- lid=*
*8-dep=*
PARSING IN CURSOR #2 len=104 dep=0 uid=0 oct=2 lid=0 tim=13651992547 hv=3760112805 ad='284c0e6c' sqlid='6shmgvbh1xj55'
INSERT INTO employee(ID,NAME,department_id, DEPARTMENT_SUB_ID) VALUES(10002, 'employee', 12, 0)
END OF STMT
PARSE #2:c=93750,e=102539,p=24,cr=471,cu=0,mis=1,r=0,dep=0,og=1,plh=0,tim=13651992547
EXEC #2:c=0,e=0,p=5,cr=1,cu=7,mis=0,r=1,dep=0,og=1,plh=0,tim=13651992547
STAT #2 id=1 cnt=0 pid=0 pos=1 obj=0 op='LOAD TABLE CONVENTIONAL  (cr=1 pr=5 pw=0 time=0 us)'
CLOSE #2:c=0,e=0,dep=0,type=0,tim=13652013059Thnak you a lot guys,
Smith

Answer 1

794130 wrote:
Thank you,
Sorry, I am new in Oracle and I want to get things really clear (something that is diifficult I think)
When an end user submit a query, one user process communicates the query to a server process.
The server process analyse the syntax and the symentic of the query, this known as the parse process.
The syntax of the query and the tables, columns are verified against the database buffer cache.
One PGA is allocated to store the query.
The server process read from the datafile and gets the results and store it into the shared pool.
The result is then back to the user process and then to the end user
Is it correct ?
Thank you all,
SSome of the above concepts are close. There is a nice description in the Oracle Database Concepts guide of what happens during the processing of a SQL statement (see the stages listed in the documentation):
http://download.oracle.com/docs/cd/B19306_01/server.102/b14220/sqlplsql.htm#sthref3460
It is probably a good idea to distinguish between a hard parse, a soft parse, and a session cursor cache hit:
http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/glossary.htm#sthref1591
The database buffer cache is not used to verify the validity of SQL statements, but instead as a means to reduce the number of disk accesses that are required to return a query result to a client computer.
One or more pieces of PGA memory may be used simultaneously while processing a SQL statement. I have a couple of blog articles that show multiple PGA memory allocations in use at the same time.
The server process may not need to access a physical data file to return the query results to a client computer, depending of course on the current contents of the buffer cache.
I recommend that you wait a while before trying to work with 10046 trace files. Right now the contents are probably providing too much detail for you, although I definitely recommend that you return to working with 10046 trace files at a later time. A good starting point is either the free Database Concepts Guide:
http://download.oracle.com/docs/cd/B19306_01/server.102/b14220.pdf
or Tom Kyte's "Expert Oracle Database Architecture: Oracle Database Programming 9i, 10g, and 11g Techniques and Solutions, Second Edition" book. You can read my review of that book on Amazon's website:
http://www.amazon.com/Expert-Oracle-Database-Architecture-Programming/dp/1430229462/ref=dp_ob_title_bk
Charles Hooper
Co-author of "Expert Oracle Practices: Oracle Database Administration from the Oak Table"
http://hoopercharles.wordpress.com/
IT Manager/Oracle DBA
K&M Machine-Fabricating, Inc.