RE: looking for thoughts/advice on AWR_REPORT_HTML and UTL_SMTP
Date: Fri, 5 Oct 2012 08:32:38 -0500
Message-ID: <F05D8DF1FB25F44085DB74CB916678E88515EC2FEA_at_NADCWPMSGCMS10.hca.corpad.net>
I'll give that a try - I was thinking about it and I believe it's the awr_report_html function that is taking some time to return and not the actual building of the CLOB.
Thanks again!
Chris
-----Original Message-----
From: Administrator User [mailto:jonathan_at_jlcomp.demon.co.uk]
Sent: Friday, October 05, 2012 1:34 AM
To: Taylor Christopher - Nashville; oracle-l_at_freelists.org
Subject: RE: looking for thoughts/advice on AWR_REPORT_HTML and UTL_SMTP
Just had a simple thought.
If most of the excessive is due to concatenating with a CLOB for each line of the report, concatenate with a varchar2() variable - which can get to 32KB in pl/sql. Then concatenate the varchar2() with the CLOB every few hundred times round the loop - you might guess at 400 times (assuming 80 character strings), you might check the length of each string and keep a running total as you take each string out of the cursor.
Regards
Jonathan Lewis
From: oracle-l-bounce_at_freelists.org [oracle-l-bounce_at_freelists.org] on behalf of Administrator User [jonathan_at_jlcomp.demon.co.uk] Sent: 05 October 2012 07:06
To: Christopher.Taylor2_at_parallon.net; oracle-l_at_freelists.org Subject: RE: looking for thoughts/advice on AWR_REPORT_HTML and UTL_SMTP
You didn't say which version of Oracle, and that could be relevant.
I ran your select statement from SQL*Plus, and then called your procedure from SQL*Plus. In 11.1.0.7 the change in "db block gets" (to pick just one of the more obvious stats) was dramatic, so it's possible that there's some feature of the simple concatenation of LOBs that makes a difference.
I wrote something about a similar anomaly a few years ago, although the strategy for improvement doesn't help: http://jonathanlewis.wordpress.com/2009/07/09/concatenating-lobs/
You might try explicit use of dbms_lob.create_temporary_lob (with the cache attribute) and dbms_lob.wrte_append() in case it makes a difference - but I suspect that's what your code is doing under the covers anyway.
Regards
Jonathan Lewis
From: oracle-l-bounce_at_freelists.org [oracle-l-bounce_at_freelists.org] on behalf of Christopher.Taylor2_at_parallon.net [Christopher.Taylor2_at_parallon.net] Sent: 04 October 2012 21:04
To: oracle-l_at_freelists.org
Subject: looking for thoughts/advice on AWR_REPORT_HTML and UTL_SMTP
I figured out how to send attachments using UTL_SMTP (from code found on the web) and the code I'm using uses a clob variable to build the attachment. So I pieced together a function to build a clob from DBMS_WORKLOAD_REPOSITORY.AWR_REPORT_HTML and call that function from my mail procedure.
This works surprisingly well to email me a daily AWR report (for a specific window of time - nightly batch cycle) *yet* the performance is slow to build the clob.
I had looked for a way to read the AWR_REPORT_HTML results directly into an attachment but I couldn't figure it out (being very non-proficient in pl/sql) so I was wondering if there was a better way to do this? (To capture the results of AWR_REPORT_HTML and mail them as an attachment).
I was thinking I should probably use a bulk collect here perhaps? Or am I overthinking this?
Here's my clob function (just for proof of concept):
CREATE OR REPLACE FUNCTION html_clob
RETURN CLOB
IS
p_attach_clob CLOB := NULL;
CURSOR c1
IS
SELECT
output
FROM
TABLE (sys.DBMS_WORKLOAD_REPOSITORY.awr_report_html (99999999,
1,
20003,
20011)); BEGIN
FOR rec IN c1
LOOP
p_attach_clob := p_attach_clob ||chr(13)||chr(10)|| rec.output; END LOOP; RETURN p_attach_clob;
END;
/
--
http://www.freelists.org/webpage/oracle-l--
http://www.freelists.org/webpage/oracle-l
--
http://www.freelists.org/webpage/oracle-l
Received on Fri Oct 05 2012 - 15:32:38 CEST