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Understanding the SCN In order to understand how Oracle performs recovery, it’s first necessary to understand Oracle’s SCN in terms of the various places where it can be stored and how it’s used for instance and media recovery. The SCN is an internal number maintained by the databasemanagementsystem (DBMS) to log changes made to a database. The SCN increases over time as changes are made to the database by Structured Query Language (SQL). By understanding how the SCN is used, you can understand how Oracle recovery works. Oracle9i enables you to examine the current SCN using the following SQL: SQL> select dbms_flashback.get_system_change_number from dual; Whenever an application commits a transaction, the log writer process (LGWR) writes records from the redo log buffers in the System Global Area (SGA) to the online redo logs on disk. LGWR also writes the transaction’s SCN to the online redo log file. The success of this atomic write event determines

http://download.oracle.com/docs/cd/E11882_01/install.112/e10840/remove_oracle_sw.htm#CEGBAJIA Oracle 11g Database software utilizes a completely different method of removing the Database software, instead of the the 'traditional' method of the OUI GUI The full document is in the above link, but in a nutshell, there is a deinstall tool located in $ORACLE_HOME/deinstall called deinstall There are are a number of options that could be used, -home,-silent,-checkonly,-local etc which are all fully explained in the document. This completely removes all of the binaries and the related HOME , BASE and oraInventory locations. However the oraInventory location details still exist in /etc/oraInventory which will still need to be removed The Agent software can be removed by typing the following and highlighting the agent oracle home and clicking remove $<ORACLE_HOME>/oui/bin/runInstaller -deinstall -removeallfiles R

RAC Filesystem Options PLEASE NOTE THAT THIS ARTICLE IS BASED ON 10g . 11g may have different options eg ACFS RDBMS Server DBAs wanting to create a 10g Real Applications Cluster face many configuration decisions. One of the more potentially confusing decisions involves the choice of filesystems. Gone are the days when DBAs simply had to choose between "raw" and "cooked". DBAs setting up a 10g RAC can still choose raw devices, but they also have several filesystem options, and these options vary considerably from platform to platform. Further, some storage options cannot be used for all the files in the RAC setup. This article gives an overview of the RAC storage options available. RAC Review Let's begin by reviewing the structure of a Real Applications Cluster. Physically, a RAC consists of several nodes (servers), connected to each other by a private interconnect. The database files are kept on a shared storage subsystem, where they'

11g R2 - Moving your voting disk and cluster registry What happens if you've created your voting disk or cluster registry in the wrong place? They're very simple to move, for example to move them from a cluster filesystem to ASM OCR Login as root Run ocrcheck to see where your existing OCR location (so you can delete it later). ocrcheck Status of Oracle Cluster Registry is as follows :        Version                  :          3        Total space (kbytes)     :     262120        Used space (kbytes)      :       2744        Available space (kbytes) :     259376        ID                       :  277541681        Device/File Name         :  /OCR/b-rac-cluster/ocr                                   Device/File integrity check succeeded        Cluster registry integrity check succeeded        Logical corruption check succeeded # ocrconfig -add +DATA # ocrconfig -delete /OCR/b-rac-cluster/ocr Run ocrcheck to c

CRS eating CPU on VMware http://www.oracloid.com/2007/10/crs-eating-cpu-on-vmware/#more-61 October 30th, 2007 Alex Gorbachev Leave a comment Go to comments Some time ago (yeah… shame on me) I mentioned having troubles running CRS on virtual machines using VMware Server. I found a solution a while ago and, since I promised to share if I find anything, now is the time. First of all, I’m happy to admit that my observations regarding Windows hosted VM’s running better compare to Linux hosted were wrong. Indeed, how can Windows run faster than Linux?! I used VMware Server 1.0.3. As host OS I used 64 bit Ubuntu or 32 bit Windows. Guest OS was 32 bit Oracle Enterprise Linux 4 (a la Larry Hat 4). As you could see later, I tried VMware Workstation 6.0 as well without any visible improvements. For shared storage I use either NFS exports from host OS (when using Ubuntu) or Openfiler when using Windows (even more CPU saturation). To

1. Configure the server disk arrays.  Our mysql standard is:     R1  P1 /              P2 /swap     R10 P1 /mysqldata1     R1  P1 /mysqllogs1     R1  P1 /mysqltemp     This will depend on physical / virtual and number of available disks / size of system.     On a vm environment we typically would split the partitions as above but the disk level Raid configuration would not apply. 2.  Download the 64bit mysql rpm files for server and client and copy onto the new Redhat server:       MySQL-server- -<version> .el7.x86_64.rpm       MySQL-client- <version> .el7.x86_64.rpm 3.  Before install check for any different versions of MySQL rpm installed , If it is  then that should be removed      rpm -qa |grep mysql      eg.  rpm -ev --nodeps mysql-community-libs-compat-5.7.19-1.el7.x86_64   ( this is just an example but follow the list to remove all the rpm displayed by the above command)         Remove mysql directory from /var/lib  and subsequent log files with in /va

 OMS Heap Memory Max Changes  ------------------------------------ oracle@xxxcloud1r:/u01/app/oracle/product/middleware3/oms/bin> emctl get property -name OMS_HEAP_MAX Oracle Enterprise Manager Cloud Control 12c Release 5 Copyright (c) 1996, 2015 Oracle Corporation.  All rights reserved. SYSMAN password: Value for property OMS_HEAP_MAX for oms local_oms is 1740M  oracle@xxxcloud1r:/u01/app/oracle/product/middleware3/oms/bin> emctl status oms -details Oracle Enterprise Manager Cloud Control 12c Release 5 Copyright (c) 1996, 2015 Oracle Corporation.  All rights reserved. Enter Enterprise Manager Root (SYSMAN) Password : Console Server Host        : xxxcloud1r.app.netr.xxxx.xxxxx.uk HTTP Console Port          : 7788 HTTPS Console Port         : 7802 HTTP Upload Port           : 4889 HTTPS Upload Port          : 4903 EM Instance Home           : /u01/app/oracle/product/gc_inst1/em/EMGC_OMS1 OMS Log Directory Location : /u01/app/oracle/product/gc_inst1/em/EMGC_OMS1

SQL Server 2017 Cumulative Update  11 Have applied the update release on the RTM release.  Please see screenshots which makes self explanatory. Need to take  downtime for this. Run the setup file from its location File Name : SQLServer2017-KB4462262-x64.exe