Oracle says "Performance degradation is the expected behavior"

Question

Guys,
Yes, you read the title correct.
We were testing our app on a new Oracle 11g 3 node RAC (with Netapp storage) / Apex 3.1.2 and noticed poor performance. Since the environment is completely new we thought we did something wrong in the configuration.
We also opened a SR with Oracle and provided them all the data for diagnostics.
(I will post the Oracle's response in the subsequent posts since I ran into issue with this forum. I don't know why nothing is working for me today)
Not only that, Oracle said, the following query is causing the system slowdown and tune this query (Again in seperate post).
Any help will be appreciated on tuning this query
Thanks
Balaji Chellappa
Note: I am posting this thread in pieces since this forum doesn't let me post in one shot.
{color:#0000ff}Hi,
It looks like you may be running into Bug 4755226, which unfortunately is nto really a bug as it is expected behavior.
The issue appears to be when using the owa commands.
You will need to determine what your code is doing at the time that the issue is occurring, then the {color:#ff0000}*code will need to be modified so it is not making as many owa calls*{color}
Please review the above as well as Bug 4755226 and let me know your status.
Thanks
{color}[{color:#0000ff}https://metalink.oracle.com/CSP/main/article?cmd=show&type=BUG&id=4755226{color}|https://metalink.oracle.com/CSP/main/article?cmd=show&type=BUG&id=4755226]
{color:#0000ff}-----
The following procedure is doing a high number of GET requests causing system slowdown.
QUESTION
=========
1) Are you familiar with this procedure?
SQL ID: cp9jr3hp1jupk
declare rc__ number; simple_list__ owa_util.vc_arr; complex_list__ owa_util.vc_arr; begin owa.init_cgi_env(:n__, :nm__, :v__); htp.HTBUF_LEN := 63; null; null; simple_list__(1) := 'sys.%'; simple_list__(2) := 'dbms\_%'; simple_list__(3) := 'utl\_%'; simple_list__(4) := 'owa\_%'; simple_list__(5) := 'owa.%'; simple_list__(6) := 'htp.%'; simple_list__(7) := 'htf.%'; if ((wwv_flow_epg_include_modules.authorize('f') = false) or (owa_match.match_pattern(p_string => 'f' /* */, p_simple_pattern => simple_list__ , p_complex_pattern => complex_list__ , p_use_special_chars => false))) then rc__ := 2; else null; null; f(p=>:p); if (wpg_docload.is_file_download) then rc__ := 1; wpg_docload.get_download_file(:doc_info); null; null; null; commit; else rc__ := 0; null; null; null; commit; owa.get_page(:data__, :ndata__); end if; end if; :rc__ := rc__; end;
Thanks{color}

Answer 1

Guys,
We had a similar issue with our system, where during peak periods our CPU is running at 100% most of the time. Our DBA isolated the problem to the SQL below:
declare
rc__ number;
simple_list__ owa_util.vc_arr;
complex_list__ owa_util.vc_arr;
begin
owa.init_cgi_env(:n__,:nm__,:v__);
htp.HTBUF_LEN := 255;
null;
null;
simple_list__(1) := 'sys.%';
simple_list__(2) := 'dbms\_%';
simple_list__(3) := 'utl\_%';
simple_list__(4) := 'owa\_%';
simple_list__(5) := 'owa.%';
simple_list__(6) := 'htp.%';
simple_list__(7) := 'htf.%';
simple_list__(8) := 'wpg_docload.%';
if ((owa_match.match_pattern('f', simple_list__, complex_list__, true))) then
rc__ := 2;
else
null;
null;
f(p=>:p);
if (wpg_docload.is_file_download) then
rc__ := 1;
wpg_docload.get_download_file(:doc_info);
null;
null;
null;
commit;
else
rc__ := 0;
null;
null;
null;
commit;
owa.get_page(:data__,:ndata__);
end if;
end if;
:rc__ := rc__;
end;
The block of code above was getting executed too many times. He reversed engineered the process in order to find out how the block above was getting generated and executed. He found out that it has to do with references to "Shared Images" in the "Page Template" of ApEx. When you reference images, js script or css files in your stylesheet using the #WORKSPACE_IMAGES# subtitution string, #WORKSPACE_IMAGES# actually translates to:
wwv_flow_file_mgr.get_file?p_security_group_id=923024072426648&p_fname=[FILE_NAME]
Every reference to an image, css, js, etc from the "Shared Repository" in ApEx is a database call. We optimized our application by removing reference to #WORKSPACE_IMAGES# (by moving images, css, js out of the database and into the web server) in our page tempates and the performance boost was amazing!
For more information about our experience, visit [Improving Performance of Your Oracle Application Express Software|http://www.web-backlinks.com/blog/index.php/2009/02/04/improving-performance-of-your-oracle-application-express-software/].
Cheers,
Ariel