Data Dictionary Objects:
A Match code is a tool tip to help us to search for the data records in the system. Match codes are an efficient and user friendly search where key of a record is unknown.
DELETE ADJACENT DUPLICATES FROM itab COMPARING ALL FIELDS.
Call By Value:creates a new memory location for use within the subroutine. The memory is freed once it leaves the subroutine, changes made to the variable are not affected outside the subroutine.
Call by Reference : passes a pointer to the memory location. Changes to the variable within the subroutine affects the variable outside the subroutine.
Read lock (shared lock):
Protects read access to an object. The read lock allows other transactions read access but not write access to the locked area of the table.
Write lock (exclusive lock):
Protects write access to an object. The write lock allows other transactions neither read nor write access to the locked area of the table.
Enhanced write lock (exclusive lock without cumulation):
Works like a write lock except that the enhanced write lock also protects from further accesses from the same transaction.
LockObjects used to synchornize access of several users using same data.
The basic difference is database tables are stored in DB serverand the internal tables are virtual tables these are created run time only
Internal tables are created dynamically, the memory of internal tables is not permant memory, for internal tables the memory will be created in the application server and it is external memory and terminates after the program termination.
After executing first write statement in start-of-selection event.
There are three type of buffer:
single record->it buffers only records based on select query statement.
generic buffer->it buffers all the records which match to primary key and generic key
full buffer :Buffering is use for improve performance.
We can use TC SE93 for creating our own transaction code.
The Table attributes determine who is responsible for maintaining a table and which types of access are allowed for the table.
The most important table attributes are:
Value table is maintained at Domain level in SAP. During domain creation, value range of the domain i defined by specifying value table.
User can create a Database table in two ways:
You use the delivery class to control the transport of table data for an installation, upgrade, or client copy and transports between customer systems. The delivery class is also used in the extended table maintenance.
There are the following development classes:
SQL Tracer is a tool used to measure the performance of ABAP program.
A Hot spot is a list area where the mouse pointer appears as an upright hand symbol. When a user points to that area, a single click does the same thing as a double click. Hot spots are supported from R/3 release 3.0.