Technology Questions

Call transaction is faster than session method. But usually we use session method in real time…because we can transfer large amount of data from internal table to database and if any errors in a session, then process will not complete until session get correct.

DeCLarations GENerator : used to create the host language copy books for the table    definitions. Also creates the DECLARE table.

Constraints enable the RDBMS to enforce the integrity of the database automatically, without the need to create triggers, rule or defaults.

Types of Constraints: NOT NULL, CHEQUE, UNIQUE, PRIMARY KEY, FOREIGN KEY.

The following are the areas of concern for tuning:

- Memory Usage

- Data Storage

- Data Manipulation

- Physical Storage

- Logic Storage

- Network Traffic

Tuning Memory Usage: In Oracle 10g, we can use the Automatic Workload Repository (AWR) toolset to gather and manage statistical data but in case of Oracle 11g, we can use new initialization parameters such as MEMORY_TARGET to further control the overall memory used by Oracle. It helps us to tune the database automatically when we don’t have time to read the AWR report.

Tuning Data Manipulation: There are two ways to tune Data manipulation in Oracle one way is through Conventional Path mode and second is Direct Path mode.

Tuning Physical Storage: We need to tune the physical storage because it limits the disk in database. This can be done by: Distributing I/O, Striping and Mirroring.

array_flip exchange the keys with their associated values in array ie. Keys becomes values and values becomes keys.

<?php
$arrayName    = array("course1"=>"php","course2"=>"html");
$new_array    = array_flip($arrayName);
print_r($new_array);
?>

OUTPUT :

Array
(
[php]     => course1
[html]    => course2
)

Primary key constraint ensures that the column(s) always has a unique value to identify the record.
Example:
Below, the primary key is created for column id with name prim_id.
create table employee ( id number NOT NULL, Name varchar(200) Constraint prim_id primary key(id) );

Value type :

• Stores the data


• The value of value types is stored on the managed stack


• They are lighter objects 


• One variable can have only one value

Reference Type :

• Stores the reference to the data


• A reference type is allocated on the heap


• They are heavier objects


• Several variables can reference the same data

ABAP Editor: Tool in the ABAP Workbench in which you enter the source code of ABAP programs and check their syntax. You can also navigate from the ABAP Editor to the other tools in the ABAP Workbench.