Muhammad Nadeem Chaudhry's Blog


Time Dimension – SQL Query

Posted in Uncategorized by Muhammad Nadeem Chaudhry on January 30, 2014

This query generates a relational table storing the information needed to create an OLAP time dimension.

CREATE TABLE TIMES AS
SELECT
– DAY LEVEL
TIME_ID AS DAY_ID,
INITCAP(TO_CHAR(TIME_ID,’FMMONTH DD, YYYY’)) AS DAY_DESC,
INITCAP(TO_CHAR(TIME_ID, ‘FMDAY’)) AS DAY_NAME,
TO_NUMBER(TO_CHAR(TIME_ID – 1, ‘D’)) AS DAY_OF_WEEK,
TO_NUMBER(TO_CHAR(TIME_ID, ‘DD’)) AS DAY_OF_MONTH,
TO_NUMBER(TO_CHAR(TIME_ID, ‘DDD’)) AS DAY_OF_YEAR,
1 AS DAYS_IN_DAY,

– MONTH LEVEL
TO_CHAR(TIME_ID, ‘YYYY”-M”MM’) AS MONTH_ID,
TO_CHAR(TIME_ID, ‘FMMONTH YYYY’) AS MONTH_DESC,
DECODE(MOD(TO_NUMBER(TO_CHAR(TIME_ID, ‘MM’)), 4), 0, 4, MOD(TO_NUMBER(TO_CHAR(TIME_ID, ‘MM’)), 4)) AS MONTH_OF_QUARTER,
TO_NUMBER(TO_CHAR(TIME_ID, ‘MM’)) AS MONTH_OF_YEAR,
TO_CHAR(TIME_ID, ‘FMMONTH’) AS MONTH_NAME,
LAST_DAY(TIME_ID) AS END_OF_MONTH,
TO_CHAR(LAST_DAY(TIME_ID),’DD’) AS DAYS_IN_MONTH,

– QUARTER LEVEL
TO_CHAR(TIME_ID, ‘YYYY”-Q”Q’) AS QUARTER_ID,
INITCAP(TO_CHAR(TIME_ID, ‘FMQTH “QUARTER,” YYYY’)) AS QUARTER_DESC,
TO_NUMBER(TO_CHAR(TIME_ID, ‘Q’)) AS QUARTER_OF_YEAR,
TRUNC(ADD_MONTHS(TIME_ID,3), ‘Q’) – 1 AS END_OF_QUARTER,
(TRUNC(ADD_MONTHS(TIME_ID,3), ‘Q’) – 1) – (TRUNC(TIME_ID, ‘Q’) – 1) AS DAYS_IN_QUARTER,

– YEAR LEVEL
TO_NUMBER(TO_CHAR(TIME_ID, ‘YYYY’)) AS YEAR_ID,
(TRUNC(ADD_MONTHS(TIME_ID,12), ‘YYYY’) – 1) – (TRUNC(TIME_ID, ‘YYYY’) – 1) AS DAYS_IN_YEAR,
TRUNC(ADD_MONTHS(TIME_ID,12), ‘YYYY’) – 1 AS END_OF_YEAR,

– THIS IS THE SAME FOR ALL WEEKS
7 AS DAYS_IN_WEEK,

– CALENDAR WEEK LEVEL
TO_CHAR(TIME_ID, ‘IYYY’) || ‘-CW’ || TO_CHAR(TIME_ID, ‘IW’) AS CAL_WEEK_ID,
INITCAP(TO_CHAR(TIME_ID, ‘FMIWTH “WEEK OF” IYYY’)) || ‘, ENDING ‘ || TO_CHAR(TRUNC(TIME_ID + 7, ‘IW’) – 1, ‘FMMONTH DD, YYYY’) AS CAL_WEEK_DESC,
TO_NUMBER(TO_CHAR(TIME_ID, ‘IW’)) AS CAL_WEEK_OF_YEAR,
TRUNC(TIME_ID + 7, ‘IW’) – 1 AS END_OF_CAL_WEEK

FROM (SELECT TO_DATE(’01/01/2008′,’MM/DD/YYYY’) + ROWNUM – 1 AS TIME_ID
FROM ALL_OBJECTS
WHERE ROWNUM <= 1492)     — ADD ONE MORE DAY BY SUBTRACTING MIN-MAX DATES
ORDER BY TIME_ID;

Secure Database Passwords in an Oracle Wallet

Posted in Uncategorized by Muhammad Nadeem Chaudhry on September 10, 2013

Read article:

http://www.idevelopment.info/data/Oracle/DBA_tips/Security/SEC_15.shtml

Moreover,

SQL> connect /@orcl

impdp /@orcl

Difference between Oracle Database 10g & 11g

Posted in Uncategorized by Muhammad Nadeem Chaudhry on August 28, 2013

Please read:

Difference between Oracle 10g and 11g

Oracle Datapump Parameter REMAP_SCHEMA

Posted in Uncategorized by Muhammad Nadeem Chaudhry on July 3, 2013

Loads all objects from the source schema into a target schema.

Syntax
REMAP_SCHEMA=source_schema:target_schema

Suppose that you execute the following Export and Import commands to remap the hr schema into the scott schema:

expdp SYSTEM/password SCHEMAS=hr DIRECTORY=dpump_dir1 DUMPFILE=hr.dmp

impdp SYSTEM/password DIRECTORY=dpump_dir1 DUMPFILE=hr.dmp REMAP_SCHEMA=hr:scott

In this example, if user scott already exists before the import, then the Import REMAP_SCHEMA command will add objects from the hr schema into the existing scott schema. You can connect to the scott schema after the import by using the existing password (without resetting it).If user scott does not exist before you execute the import operation, import automatically creates it with an unusable password. This is possible because the dump file, hr.dmp, was created by SYSTEM, which has the privileges necessary to create a dump file that contains the metadata needed to create a schema. However, you cannot connect to scott on completion of the import, unless you reset the password forscott on the target database after the import completes.

Configuring Oracle Workflow for OWB

Posted in Uncategorized by Muhammad Nadeem Chaudhry on July 1, 2013

Send Report via EMail Attachment in Oracle Forms 10g

Posted in Uncategorized by Muhammad Nadeem Chaudhry on May 31, 2013

DECLARE
report_id REPORT_OBJECT := find_report_object(‘MYREPORT’);
report_message VARCHAR2(100) :=”;
rep_status VARCHAR2(100) :=”;
v_error Exception;
thelist paramlist;
BEGIN
— Create parameters list
thelist:= Get_Parameter_List(‘rep_paramlist’);
IF NOT Id_Null (thelist) THEN
DESTROY_PARAMETER_LIST(thelist);
END IF;
thelist := Create_Parameter_List (‘rep_paramlist’);

— Add report paremeters
ADD_PARAMETER(thelist, ‘FROM’,TEXT_PARAMETER, ‘abc@abc.com’);
ADD_PARAMETER(thelist, ‘SUBJECT’,TEXT_PARAMETER, ‘MRF NO:’||:GLOBAL.SIFNO);
ADD_PARAMETER(thelist, ‘PROJECT_NBR’,TEXT_PARAMETER, 968404);

— Set report object properties
SET_REPORT_OBJECT_PROPERTY(report_id,REPORT_COMM_MODE, SYNCHRONOUS);
SET_REPORT_OBJECT_PROPERTY(report_id,REPORT_FILENAME, ‘C:\workingDirectory\MRF.RDF’);
SET_REPORT_OBJECT_PROPERTY(report_id,REPORT_SERVER, ‘rep_XP_oracleasFRM’);
SET_REPORT_OBJECT_PROPERTY(report_id,REPORT_DESTYPE, MAIL );
SET_REPORT_OBJECT_PROPERTY(report_id,REPORT_DESFORMAT, ‘PDF’);
SET_REPORT_OBJECT_PROPERTY(report_id,REPORT_OTHER,’paramform=no mrfno=’||:GLOBAL.SIFNO);
SET_REPORT_OBJECT_PROPERTY(report_id,REPORT_DESNAME,’abc@abc.com’ );

— Check report status
report_message := run_report_object (report_id, thelist);
rep_status := report_object_status (report_message);
BEGIN
WHILE
rep_status in (‘RUNNING’,’OPENING_REPORT’,’ENQUEUED’)
LOOP
rep_status := report_object_status(report_message);
END LOOP;
EXCEPTION
WHEN v_error then
message(‘Error in sending Action Checklist email.’|| rep_status);
END;
END;

Moving ASM Database Files from one Diskgroup to Another

Posted in Uncategorized by Muhammad Nadeem Chaudhry on April 9, 2013

Configure Oracle Application Express (APEX) in Oracle 11gR2

Posted in Uncategorized by Muhammad Nadeem Chaudhry on September 26, 2012

In order to access the APEX application, either the embedded PL/SQL gateway or Oracle HTTP server with mod_plsql is needed. For simplicity, I’ve decided to go with the former. By using the embedded PL/SQL gateway, it will run using the Oracle XML DB HTTP server which is already in Oracle database, so there is no need to install a separate HTTP server. The Oracle’s document here explains about this as well as provides the detailed information on the post-installation.

1. To configure the embedded PL/SQL gateway:

Go to the $ORACLE_HOME/apex directory.

2. Use SQL/Plus to connect as SYS to 11g database where APEX is installed.

SYS AS SYSDBA@DB11G> @apxconf

PORT———-8080

Enter values below for the XDB HTTP listener port and the password for the Application Express ADMIN user.

Default values are in brackets [ ].

Press Enter to accept the default value

Enter a password for the ADMIN user [] admin_password

Enter a port for the XDB HTTP listener [ 8080]

…changing HTTP Port

PL/SQL procedure successfully completed.

PL/SQL procedure successfully completed.

Session altered.

…changing password for ADMIN

PL/SQL procedure successfully completed.

Commit complete.

3. Unlock the ANONYMOUS account.

SYS AS SYSDBA@ DB11G > ALTER USER ANONYMOUS ACCOUNT UNLOCK;

User altered.

4. Enable Oracle XML DB HTTP server

SYS AS SYSDBA@ DB11G > EXEC DBMS_XDB.SETHTTPPORT(8080);

PL/SQL procedure successfully completed.

SYS AS SYSDBA@ DB11G > COMMIT;

Commit complete.

5. We’re now ready to access APEX.

http://host:port/apex

http://host:port/apex/apex_admin — for admin page

Port in this case is 8080 which is the default.

Upgrade Oracle Database from 10g to 11g with Data Pump

Posted in Uncategorized by Muhammad Nadeem Chaudhry on August 27, 2012

As described in “Oracle Database Upgrade Guide 11g Release 1 (11.1)“, there are three upgrade methods offered while you want to upgrade database from 10g to 11g.

  1. Database Upgrade Assistant (DBUA)
  2. Manual Upgrade (Oracle provided scripts)
  3. Export/Import (exp/imp or expdp/impdp)

Besides benefits mentioned in above upgrade document, I’m thinking we are beneficial from using export/import approach. The reasons we decided using this method are:

  • We want to set up identical testing databases on development server first
  • We want to keep original production databases unchanged anyway for safety reason

With this approach, we first installed Oracle 11g software on development server and created empty database by using provided standard template New_Database.dbt, which could be found at $ORACLE_HOME/assistants/dbca/templates. After that, we followed the following steps to move data from 10g database to newly created 11g database.

Step 1: Pre-create tablespaces on target 11g database

Step 2: Export full database of source 10g database

expdp system@database directory=DATA_PUMP_DIR full=y dumpfile=export.dmp logfile=export.log

Step 3: Copy dumpfile over network to development server

Step 4: Grant IMPORT_FULL_DATABASE system privilege to user SYSTEM of target 11g database

Step 5: Import full database to target 11g database

Note: If you have co-existing oracle home/version on development server, please make sure switching to Oracle 11g environment, which will assure to use data pump at 11g version to import data.

Impdp system@database directory=DATA_PUMP_DIR full=y dumpfile=export.dmp logfile=import.log

Adding a new disk to a VMWare Virtual machine in Linux

Posted in Uncategorized by Muhammad Nadeem Chaudhry on August 15, 2012

I’ve been using VMWare for a while now and I always get asked some common questions about it. One of those is how to add a new virtual disk to a Linux virtual machine. So in response to that, here are the steps to adding a new SCSI based virtual disk to a CentOS Linux virtual machine. The steps for adding a disk to a Windows machine is very much the same except you would use the Disk Management utility from the Control Panel.

Step 1: Open virtual machine settings
Select your virtual machine, as you can see from the photo I selected the Infrastructure virtual machine. Next press the “Edit virtual machine settings’ to open the Virtual Machine Settings dialog.
Select your Virtual Machine

Step 2: Add new hardware
From the “Virtual Machine Settings” dialog select the “Add…” button at the bottom of the screen. From this dialog you can also modify how much memory you dedicate to the machine when it boots.
Virtual Machine Settings Dialog - /> Select the Add... button

Step 3: Start hardware wizard
Next we will walk through the “Add Hardware Wizard” the process makes it very simple to add additional hardware to a predefined virtual machine. From this screen we want to select the “Next >” button.
Add Hardware Wizard

Step 4: Select new hard disk
From this screen we can see the many types of hardware we can add to a virtual machine. You can emulate just about any piece of hardware that one can expect in a modern operating system. It definitely makes testing with different configurations and devices much easier. For our example we want to select “Hard Disk” and then select the “Next >” button.
Select Hard Disk from the Add Hardware Wizard

Step 5: Create the virtual disk
In the next screen we see the three options for adding a new disk. We can “Create a new virtual disk”, this will create a brand new disk on the guest operating system. The second option, “Use an existing virtual disk”, allows you to mount a disk from another virtual machine. I like to do this with my “source” drive. I have one virtual disk that I’ve made that has all the Oracle and Linux CDs on it, that way I can just mount it to the machine I need when I have to do a new install instead of copying the binaries I need across disks, its definitely a big time saver. The last option is to “Use a physical disk”, this allows you to mount a local physical disk to the operating system. This option is akin to NFS mounting a drive to a virtual machine. To add a new disk we select the “Create a new virtual disk” option and select the “Next >” button.
Create a New Virtual Disk from the Add Hardware Wizard

Step 6: Select type of disk
Next we want to select the type of disk. I’ve been using VMWare for a long time and agree that the recommended Virtual Disk Type should be SCSI. I don’t know why, but I’ve had much better success with the SCSI virtual disks than the IDE ones. So in this step we want to select “SCSI (Recommended)” and the “Next >” button.
Select Disk Type from Add Hardware Wizard

Step 7: Set disk size and options
Now we want to set the size of the disk we are creating. One of the nice features of VMWare is that you don’t have to allocate all of the disk when you create it. So if you create a 40 GB disk it doesn’t have to take it all right away, the disk will grow as your virtual machine needs it. I will say this is a big performance hit you take when the disk has to extend, but for most applications its OK. Also, I will warn that if the virtual disk grows and there is no physical disk left on the host operating system you will see a catastrophic failure and in most cases both the host and guest operating systems lock up and become unusable. (Don’t say I didn’t warn you) Lastly, you can split the files into 2GB sizes, while this isn’t necessary, it just makes all the disks much easier to manage and move around. For this step we want to set our disk size (12 GB in this case), I chose not to allocate the disk space right now (the machine has a 300 GB drive and has only 20 GB on it) and Split disk into 2 GB files.
Specify Disk Capacity from the Add Hardware Wizard

Step 8: Name the disk file
This is actually pretty simple in that you decide what you want to physically call the disk and where to put it. .vmdk is the extension for VMWare virtual disks. After we name the disk we can select the “Finish” button which adds the disk to the virtual machine.
Name the Virtual Disk File from the Add Hardware Wizard

Step 9: Ensure new disk exists
So now we can see that the new disk has been added to the “Virtual Machine Settings” within the selected virtual machine. From here the disk acts just like it would if you added a new disk to a standalone server. So we select the “OK” button to continue.
Review Virtual Machine Settings for the newly created disk

Step 10: Boot the virtual machine
From here we just start the virtual machine like we would normally, either by selecting the button on the toolbar or selecting the “Start this virtual machine” link.
Start the Virtual Machine

Step 11: Virtual machine start up
The machine boots normally as it would any other time.
Booting Virtual Machine...

Step 12: Create the Partition
After we’ve logged in and accessed a terminal window as root (or another user with root/sudo privs) we first want to run fdisk on the newly created drive. In Linux the first SCSI drive is sda, the second sdb, the third sdc, etc. since this was the second SCSI drive we added to the system, the device is known as /dev/sdb
The first command we want to run is fdisk /dev/sdb (NOTE: Thanks to everyone that caught my typo here) this utility works very much like the DOS utility of the old days and allows you to create and manage partitions. To create a new partition we enter the command n to create a new partition. This is going to be a primary partition p, and the first partition number 1. Because I want this disk to consume the full 12 GB I specified earlier we start at the first cylinder and end it at the last cylinder. We then want to write the partition table with the new partition we have just created so we enter the command w which writes the new table and exits fdisk.
Create new partition with fdisk

Step 13: Format the partition
Now that we’ve create the partition, we now want to format the first with the new file system. I’ve decided to use ext3 filesystem for this disk, ext3 provides all the features of the classic ext2 file system plus journaling which helps to prevent disk corruption in the event of an improper shutdown and speeds up the recovery process. For a good overview of Linux standard file systems check out this article: http://linux.org.mt/article/filesystems So, to format the new partition we enter the command mkfs -t ext3 /dev/sdb1. This command makes a new files system with the type t ext3 on the /dev/sdb1 partition, this is the first partition on the sdb disk.
Create new filesystem in the virtual machine

Step 14: Create the mount point
Determine where you want to add the new virtual disk you’ve created. I like to create a partition specifically for all the software I install after the basic Linux install called /software to do that we run mkdir /software, just a simple make directory command. Once that is complete we then want to mount the newly created partition. Because we haven’t added the partition to the /etc/fstab yet we have to mount it manually. To do that we run mount -t ext3 /dev/sdb1 /software. To break down this command we run mount with the ext3 filesystem type, the partition /dev/sdb1 to the directory /software. Pretty simple and straight forward. To check that the partition is properly mounted we run df -k which shows us the mounted partitions and the amount of available space.
Create new mount point and mount the new drive

Step 15: Open the fstab file
The fstab file holds all of the used disks and partitions, and determines how they are supposed to be used by the operating system. So we edit the file to add the newly created partition

Step 16: Modify the fstab for the new partition
After we open the fstab file in the previous step we add the following line:
/dev/sdb1 /software ext3 defaults 1 1
The first column is the partition name, the second is the default mount point, the third is the filesystem type. The fourth is the mount options, in this case I used default which mounts the drive rw, suid, dev, exec, auto, nouser and asynchronous. The 5th and 6th options are for the dump and fsck options. If dump is set to 1 the filesystem is marked to be backed up, if you are going to have sensitive material on the drive its a good idea to set it to 1. If fsck is set to greater than 1, then the operating system uses the number to determine in what order fsck should be run during start up. If it is set to 0 it will be ignored such as in the case of a cdrom drive since its a solid state disk. For more information on the fstab file check out this article: http://www.tuxfiles.org/linuxhelp/fstab.html
Lastly, we write and quit the file with the :wq command.
Editing of the fstab

So now that the fstab has been written the drive will be mounted and unmounted when the machine is either started or shutdown. So there you have it, the quick and dirty process for adding a brand new disk to a virtual machine.

Reference: http://www.matttopper.com/2006/05/adding-a-new-disk-to-a-vmware-virtual-machine-in-linux/

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