Yearly Archives: 2021

Go to MOS directly from Google results – part 1

This entry was posted in My Oracle Support Oracle on by

I’m sure you know this annoying sequence, when you click on a My Oracle Support result from Google:

It would be nice to go from the Google results page directly into the MOS website.

This can be easily done with a Google Chrome (I believe also exists for Firefox and Edge) that rewrites the URL.

I used Redirector which I configured with:

To make copy/paste easier:

Redirect: ^(?:https?://)support.oracle.com/knowledge/(.*)/(.*)_([0-9]).html
To: https://support.oracle.com/epmos/faces/DocumentDisplay?id=$2.$3

Now from Google results I go directly the Oracle Support note page. 🙂

OEM Agent error with [handshake has no peer]

This entry was posted in OMS on by

At a client, there is OEM 13.4 running without problems, being patched every three months with the latest PSU.

Some old VMs have old Agents, like OEM Agent 13.2.

Recently we noticed one corrective action failed with:

Corrective action output=Step aborted after 30 failed attempts to run. Last captured error message was: Caught agent exception[unable to connect to http server at https://srv01234.domain.com:3872/emd/main/. [handshake has no peer](oracle.sysman.emSDK.agent.comm.exception.VerifyConnectionException)]
Error communicating with agent. Please also check incident console for possible job-system related problems.

The problem is that OEM Agent 13.2 uses by default the following Ciphers to communicate:

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Explore multiple optimizer features and fixes with SQLT Xplore

This entry was posted in Oracle Oracle 10g Oracle 11g Oracle 12c Oracle 19c Performance and tagged parsing regression sqlt on by

Yesterday I described how I come to SQLT Xplore and it helped me to find out, on Oracle 12.2.0.1, that optimizer_features_enable=8.1.3 decreased the parsing time of a query from 5 seconds to 0.2 seconds. Today I show how to use SQLT Xplore.

What is SQLT Xplore?

SQL Xplore automatises the test of almost 2’000 optimizer parameters and bug fixes control against one query, allowing to discover which parameter was eventually the reason of a performance regression.

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Long parsing on Oracle 12.2 and the discovery of SQLT Xplore

This entry was posted in Oracle Oracle 11g Oracle 12c Oracle 19c Performance on by

Today I discovered a fantastic free tool from Oracle: SQLT Xplore!

At a client I had one query that took long time parsing. The tkprof result of the 10046 trace showed it took 5 seconds to parse:

call     count       cpu    elapsed       disk      query    current        rows
------- ------  -------- ---------- ---------- ---------- ----------  ----------
Parse        1      5.17       5.30          0          0          0           0
Execute      1      0.00       0.00          0          0          0           0
Fetch        1      0.00       0.00          0        665          0          26
------- ------  -------- ---------- ---------- ---------- ----------  ----------
total        3      5.17       5.30          0        665          0          26

Looking around I’ve noticed that disabling the cost based transformation:

ALTER SESSIONS SET "_optimizer_cost_based_transformation"=off;

…the query was much faster to parse: only 0,5 seconds.

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