ORATraining Blog

Nowadays DBAs face requirements for migrating databases across different platforms like from Windows to Linux or Solaris or vice versa. While doing this we would require to use transportable tablespaces or cross-platform transportable tablespaces. In order to decide whether the migration would be simple or will involve file conversion, following command is used to identify platform endian format. If the endian formats are same then the process pretty straightforward.

SQL> select * from v$transportable_platform order by platform_id;

PLATFORM_ID	PLATFORM_NAME	ENDIAN_FORMAT
1	Solaris[tm] OE (32-bit)	Big
2	Solaris[tm] OE (64-bit)	Big
3	HP-UX (64-bit)	Big
4	HP-UX IA (64-bit)	Big
5	HP Tru64 UNIX	Little
6	AIX-Based Systems (64-bit)	Big
7	Microsoft Windows IA (32-bit)	Little
8	Microsoft Windows IA (64-bit)	Little
9	IBM zSeries Based Linux	Big
10	Linux IA (32-bit)	Little
11	Linux IA (64-bit)	Little
12	Microsoft Windows 64-bit for AMD	Little
13	Linux 64-bit for AMD	Little
14	HP Open VMS	Little
15	Apple Mac OS	Big

Many users face issue running Oracle forms on Microsoft Internet Explorer 8 (IE8) which causes the page to redirect to following url

res://ieframe.dll/acr_depnx_error.htm#<domain>,http://<server>:<port>/forms/frmservlet?config=<config>

It displays following error.

Internet explorer has closed this webpage to help protect your computer

A malfunctioning or malicious add-on has caused Internet Explorer to close this webpage.

Solution:

Goto Internet Explorer -> Tools -> Internet Options -> Advanced -> Scroll down to Security -> Uncheck “Enable memory protection to help mitigate online attacks*”

Close all browser windows and restart the browser. The issue should have been fixed

Oracle PL/SQL Quick Reference

 
PL/SQL Block Structure

DECLARE --Optional

  --Variables, Cursors, User-defined exceptions

BEGIN --Mandatory

  --SQL statements

  --PL/SQL statements

EXCEPTION --Optional

  --Actions to perform when errors occur

END; --Mandatory

 Read more...

Oracle SQL Quick Reference

SELECT Query Statement

SELECT [DISTINCT] {*, column [alias],…}

FROM table

WHERE condition(s)]

ORDER BY {column, exp, alias} [ASC|DESC]]

NOTE:

Avoid using DISTINCT with large table as it first does sorting of all the rows and then eliminates duplicate rows, so need a full table scan and thus it’s very slow.

ORDER BY is the last clause to get executed and thus could see all the column aliases; You can sort by a columns that is not in SELECT list; Default sorting order is Ascending (ASC)

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Oracle SQL Tuning Tips

consideration when writing an SQL statement is that it returns a correct result. The second is that it be the most efficient for a given situation.  You can use many different SQL statements to achieve the same result. It is often the case that only one statement will be the most efficient choice in a given situation.

Remember that processing SQL is a sequence of Parse (syntax check and object resolution), Execution (required reads and writes), and Fetch (row results retrieved, listed, sorted, and returned). SQL “tuning” consists, quite simply, of reducing one or more of them.

Note: generally Parse is the greatest time and resource hog. Parse overhead can be minimized by the use of Procedures, Functions, Packages, Views, etc.

Inadequate performance can have a significant cost impact on your business. A poor performing system and application can result in customer dissatisfaction, reduced productivity, and high costs. It is absolutely critical that the system’s performance is operating at its peak levels.

Following are some general tips that often increase SQL statement efficiency. Being general they may not apply to a particular scenario. Read more…