Explain about roll area , Dispatcher, ABAP-Processor.

Roll area is nothing but memory allocated by work process. It holds the information needed by R/3 about programs execution such as value of the variables.

Dispatcher :All the requests that come from presentation server will be directed first to dispatcher. Further dispatcher sends this requests to work process on FIFO(First In and First Out) basis. Dispatcher recieves the request from client and assigns the request to one of the work process.

Roll area: Each workprocess works in a particular memory that memory is known as Role Area, which consists of User context and session data. ABAP- Processor :is an interpretor which can execute logic

From Excel to ABAP – Is batch mode possible ?

DATA w_file TYPE string.
* Convert the file path into string
w_file = p_input.

* Internal Table should have same field sequence as EXL File.

CLEAR t_upload.
REFRESH t_upload.

* Call function to upload the data into internal table
CALL FUNCTION ‘GUI_UPLOAD’
EXPORTING
filename = w_file
filetype = ‘ASC’
has_field_separator = ‘X’
TABLES
data_tab = t_upload
EXCEPTIONS
file_open_error = 1
file_read_error = 2
no_batch = 3
gui_refuse_filetransfer = 4
invalid_type = 5
no_authority = 6
unknown_error = 7
bad_data_format = 8
header_not_allowed = 9
separator_not_allowed = 10
header_too_long = 11
unknown_dp_error = 12
access_denied = 13
dp_out_of_memory = 14
disk_full = 15
dp_timeout = 16
OTHERS = 17.
IF sy-subrc NE 0.
* MESSAGE ID sy-msgid TYPE sy-msgty NUMBER sy-msgno
* WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4. ELSE.
* Delete the first row of heading from the uploaded table
DELETE t_upload INDEX 1.
ENDIF. ” IF sy-subrc EQ 0.

About internal tables

An internal table is a run time instance. It get created when program starts execution. It get destroyed when program terminates. It has two different parts: HeaderLine(optional) and Body(Compulsory). Any value that comes to or goes from interanal table, that travels through headerline.

Explain row type and line type concept

Line type refers to the structure of an internal table,whereas row type is the actual part that contains the data and it refers to the table body.creating internal table using line type and row type concept is for reusability purpose.Line type and Row type are defined at DDIC LEVEL.

What happens “Update” command is used without where clause ?

It will update all the records with same name in the particular field of the table.

If we dont mention “WHERE” clause in the UPDATE statement, it will update all records satisfying the given condition (if given any ) in the table !

Based on query condition. it will update all the fields which are mentioned in the query.
ex: update employee set firstname= @firstname,lastname=@lastname where employee_id =@employee_id.
so in the above case nothing wil be happen if you used where clause or not.
if you have many statements in the query you need to use the where clause.

What is an ABAP/4 Query?
ABAP/4 Query is a powerful tool to generate simple reports without any coding. ABAP/4 Query can generate the following 3 simple reports: Basic List: It is the simple reports. Statistics: Reports with statistical functions like Average, Percentages. Ranked Lists: For analytical reports. – For creating a ABAP/4 Query, programmer has to create user group and a functional group. Functional group can be created using with or without logical database table. Finally, assign user group to functional group. Finally, create a query on the functional group generated.

Difference between transparent tables and pooled tables.

Transparent tables: Transparent tables in the dictionary has a one-to-one relation with the table in database. Its structure corresponds to single database field. Table in the database has the same name as in the dictionary. Transparent table holds application data.

Pooled tables. Pooled tables in the dictionary has a many-to-one relation with the table in database. Table in the database has the different name as in the dictionary. Pooled table are stored in table pool at the database level.

What are indexes?
Indexes are described as a copy of a database table reduced to specific fields. This data exists in sorted form. This sorting form ease fast access to the field of the tables. In order that other fields are also read, a pointer to the associated record of the actual table are included in the index. The indexes are activated along with the table and are created automatically with it in the database.