Submitted by dmann on Mon, 05/18/2020 - 12:50
As we move on to 12.2 and 19c we're seeing more instances where simple schema export/import migrations are missing objects on the target database.
If you do object counts after a simple schema migration... Or see something like this pop up in your impdp logs:
Submitted by dmann on Fri, 02/14/2020 - 13:24
Create keystore with a self signed cert
keytool -genkey -keystore /path/keystore.jks -alias selfsigned -keyalg RSA -keysize 4096 -validity 720
Enter details for cert and enter password = password123
Update Tomcat server.xml
Submitted by dmann on Wed, 02/06/2019 - 16:10
If you are getting odd abends on your Golden Gate replicats due to trail file corruption, make sure you visit your filesystem options for the filesystem where the manager process writes the trail files.
Long story short is that we were finding large swaths of Zeroes appearing in our trail files. Using logdump I could see the header of the trail file was OK, but somewhere down the line a valid record would be followed by straight up zeroes. Lots of them. I verified this using logdump and a hex editor.
Submitted by dmann on Mon, 10/22/2018 - 23:11
I find Encryption is blamed for a lot of performance issues so wanted to find out for myself how much of a performance hit we might be taking for common operations. There ain't no free lunch. Adding any extra processing or manipulation to an operation is going to add time to that operation.
Where can encryption be enabled when working with an Oracle database?
For Oracle there are two places to introduce encryption:
Submitted by dmann on Thu, 10/04/2018 - 17:24
If you have clients connecting to a server and the clients don't specify a specific encryption algorithm in SQLNET.ENCRYPTION_TYPES_CLIENT, be aware that the order of the algorithms listed in SQLNET.ORA on the server side matters...
If you don't specify SQLNET.ENCRYPTION_TYPES_CLIENT from a 12.2 client configuration, a SQLNet client side trace shows the following possibilities, the choices are listed from most secure to least secure:
(3775811968) [04-OCT-2018 19:47:44:284] nam_gic: Counting # of items in "SQLNET.ENCRYPTION_TYPES_CLIENT" parameter
Submitted by dmann on Thu, 06/28/2018 - 12:40
I've been diving into more OEM Automation and collecting information here.
While the Oracle example scripts are a great way to find out how to interact with OEM via the emcli and python/jython interface, there doesn't seem to be much info about how this all gets done. You feed a Python script to emcli and magic happens right?
Adeesh Fulay has a great intro article here.
Submitted by dmann on Fri, 02/24/2017 - 17:03
After 4 unexplained crashes and a stalled Sev 1 SR I was pulling my hair out. Particularly vexing was the fact that a user was running a distributed query which was crashing a remote database.
I isolated the 4 crash times for the remote database and I wanted to see what users and SQLs were running on the local database up until the crash time. So for a crash happening around 11:16 I would use the following query.
Submitted by dmann on Thu, 09/15/2016 - 17:49
To troubleshoot a problem I needed to copy a database's worth of files out of an ASM diskgroup and onto the filesystem. I searched around and checked help for ASMCMD assuming there was a recursive option. I found references to one in some places on the interwebs, even official Oracle references to it like Unable To Copy Directory Using ASMCMD Cp -r Command (Doc ID 829040.1) but struck out when trying to do this on 11g and 12c ASM installs.
Submitted by dmann on Wed, 04/27/2016 - 12:24
I recently came across a legacy database that was using Oracle FLOAT datatype for Primary and Foreign Keys. As the database needed some attention I was asked to get data types in order and get rid of the FLOATs in favor of NUMBER data types.
Submitted by dmann on Tue, 03/08/2016 - 11:23
I've gotten a lot of mileage out of my old SQL Developer Archive Log Count Heat Map report that I created in SQL Developer. I was recently asked to estimate the amount of redo that might be sent to a DataGuard standby. Searching The Google for this and I found some methods for calculating Network Bandwidth but I wanted to start with raw redo generated from an instance using information from v$archived_log.