Oracle 11g…

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The day when Oracle 11g was made available for download on OTN, there was sort of, flood of posts in the Oracle blogsphere. Here is a quick recap of few of the posts (Whatsoever I could find through OraNA and my Netvibes)

Eddie Awad about 11g, I think he was the first one to post

Then Doug Burns here

Howard on installing 11g

Another interesting article from Howard

Tim Hall about 11g

Tim Hall on installing 11g

Then Laurent

An article on ADR by Virag Sharma on his blog

Jaffar about Active Standby database

A 11g PL/SQL article on AMIS blog

Well, if you don’t want to get into any hassles and just want to download Oracle 11g, you can get it here. (As of now its available for Linux x86 only).

Sidhu

Why Linux cries about "1024 cylinders thing" at the time of installation…

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I have been installing Linux for last 6 years and for more than half the number of times, came across a message something like “This partitions is beyond the 1024 cylinder boundary and may not be bootable”. But never cared for it much and understood what exactly it meant to say ?

Yesterday I was reading System Admin guide to Linux by Lars Wirzenius (Thanks Howard for the link 🙂 From there I came to know what exactly that message meant. Quoting from the guide itself:

Unfortunately, the BIOS has a design limitation, which makes it impossible to specify a track number that is larger than 1024 in the CMOS RAM, which is too little for a large hard disk. To overcome this, the hard disk controller lies about the geometry, and translates the addresses given by the computer into something that fits reality. For example, a hard disk might have 8 heads, 2048 tracks, and 35 sectors per track. Its controller could lie to the computer and claim that it has 16 heads, 1024 tracks, and 35 sectors per track, thus not exceeding the limit on tracks, and translates the address that the computer gives it by halving the head number, and doubling the track number. The mathematics can be more complicated in reality, because the numbers are not as nice as here (but again, the details are not relevant for understanding the principle). This translation distorts the operating system’s view of how the disk is organized, thus making it impractical to use the all-data-on-one-cylinder trick to boost performance.
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When using IDE disks, the boot partition (the partition with the bootable kernel image files) must be completely within the first 1024 cylinders. This is because the disk is used via the BIOS during boot (before the system goes into protected mode), and BIOS can’t handle more than 1024 cylinders. It is sometimes possible to use a boot partition that is only partly within the first 1024 cylinders. This works as long as all the files that are read with the BIOS are within the first 1024 cylinders. Since this is difficult to arrange, it is a very bad idea to do it; you never know when a kernel update or disk defragmentation will result in an unbootable system. Therefore, make sure your boot partition is completely within the first 1024 cylinders.

Hope it clears the logic why Linux cries about 1024 cylinder issue at the time of installation.

You can read the guide online from the link above and download the pdf here. Its simple and concise and just too good. Small thing covering much 🙂

Sidhu

Plugged-in back to www…

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Last to last week, we shifted to a new house. As there was no internet connection, so we were without any internet access for last 2 weeks. Today we got the new internet connection. Its a DSL one. And the guy who came to do the installation threw a little bit of technical jargon like rebooting the router and so on.

It feels so good to be back in the world of www 🙂

Sidhu

Moving datafiles,control files and log files – Part 1

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Many times you need to move datafiles from one location to another. The simplest approach for this is to take the tablespace offline, copy the datafiles to new location, rename the files with alter database rename file (Except that you dont have to move the SYSTEM and UNDO tablespace, as you can’t take SYSTEM tablespace offline)


SYS@orcl AS SYSDBA> alter tablespace system offline;
alter tablespace system offline
*
ERROR at line 1:
ORA-01541: system tablespace cannot be brought offline; shut down if necessary

SYS@orcl AS SYSDBA>

Well lets try moving USERS tablespace.


SYS@orcl AS SYSDBA> column file_name format a50

SYS@orcl AS SYSDBA> set lines 100
SYS@orcl AS SYSDBA> select file_name,tablespace_name from dba_data_files where tablespace_name='USERS';

FILE_NAME                                          TABLESPACE_NAME
-------------------------------------------------- ------------------------------
C:\ORACLE\ORCL\USERS01.DBF                         USERS

SYS@orcl AS SYSDBA>

The current location of the datafile is C:\ORACLE\ORCL\. Suppose I have to move it to c:\oracle\oradata. So first lets take the tablespace offline


SYS@orcl AS SYSDBA> alter tablespace users offline;

Tablespace altered.

SYS@orcl AS SYSDBA>

Now copy the datafile to new location [Note the new directory should be already created]


C:\oracle\ORCL>copy USERS01.DBF c:\oracle\oradata
1 file(s) copied.

C:\oracle\ORCL>

Now make database aware of the new location of the datafile using alter database rename file:


SYS@orcl AS SYSDBA> alter database rename file 'c:\oracle\orcl\users01.dbf' to 'c:\oracle\oradata\users01.dbf';

Database altered.

SYS@orcl AS SYSDBA>

The last thing is to bring the tablespace online. If everything has gone rightly the message like this will appear and you can view the new location of the datafile.


SYS@orcl AS SYSDBA> alter tablespace users online;

Tablespace altered.

SYS@orcl AS SYSDBA> select file_name,tablespace_name from dba_data_files where tablespace_name='USERS';

FILE_NAME                                          TABLESPACE_NAME
-------------------------------------------------- ------------------------------
C:\ORACLE\ORADATA\USERS01.DBF                      USERS

SYS@orcl AS SYSDBA>

In next post we will discuss moving datafiles, controlfiles and logfiles.

Batch file for ftp’ing files…

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Today I came across a requirement where users needed to ftp files time and again. So ftp’ing again and again is not a very good option. I wrote a small batch file for the same. Just sharing the same over here. I created a folder ftp in C drive and a file get_file.bat
Contents of get_file.bat are:


set /p file_name=Enter the name of the file you want to ftp:
echo oracle>c:\ftp\param.cfg
echo oracle123>>c:\ftp\param.cfg
echo cd /home/oracle>>c:\ftp\param.cfg
echo lcd c:\ftp>>c:\ftp\param.cfg
bin
get %file_name%
ftp -s:param.cfg 127.0.0.1

It will create a file param.cfg having all the things like username, password and command to get the file in the same folder (c:\ftp). Then we invoke ftp with -s option with specifying the file param.cfg. It will ask the user to enter the file name and ftp the file from server to c:\ftp

Sidhu