topic Re: general in Application Development and Automation Discussions

general

Former Member — Mon, 12 May 2008 05:06:27 GMT

hi experts,

can any one give the answer to this question..

1. what r extarct data sets, what r these advantages ?

2. what processor is exisited in online program?

3. what is processor, how many processors existed in sap appliction server? and what is diff b/n proceesor and dispatcher?

Re: general

Former Member — Mon, 12 May 2008 05:19:39 GMT

Hi,

Since internal tables have fixed line structures, they are not suited to handle data sets with varying structures. For this purpose, ABAP offers the possibility to create so-called extract datasets (extracts, for short).

An extract is a sequential dataset in the memory area of the program. You can only address the entries in the dataset within a special loop. The index or key access permitted with internal tables is not allowed. You may only create one extract in any ABAP program. The size of an extract dataset is, in principle, unlimited. Extracts larger than 500 KB are stored in operating system files. The practical size of an extract is up to 2 GB, as long as there is enough space in the file system.

An extract dataset consists of a sequence of records of a predefined structure. However, the structure need not be identical for all records. In one extract dataset, you can store records of different length and structure one after the other. You need not create an individual dataset for each different structure you want to store. This fact reduces the maintenance effort considerably.

In contrast to internal tables, the system partly compresses extract datasets when storing them. This reduces the storage space required. In addition, you need not specify the structure of an extract dataset at the beginning of the program, but you can determine it dynamically during the flow of the program.

You can use control level processing with extracts just as you can with internal tables. The internal administration for extract datasets is optimized so that it is quicker to use an extract for control level processing than an internal table.

And for processors jst go to following link,

http://help.sap.com/saphelp_nw70/helpdata/en/fc/eb2d67358411d1829f0000e829fbfe/content.htm

Reward pts if helpfull

Regards,

Dhanashree

Re: general

Former Member — Mon, 12 May 2008 05:24:16 GMT

Hi Kartik,

1.By using extract datasets, you can handle groups of data with different structure and get statistical figures from the grouped data.

You need not define the structure of the extract dataset.

In contrast to internal tables, the system partly compresses exact datasets when storing them. This reduces the storage space required.

Extract datasets do not need a special work area for interface.

2&3

Dispatcher is the control agent which manages the

resources for the R/3 applications

Application server contains Dispacher.

Dispatcher contains queue file and workprocessors.

When we execute object, the request goes to dispatcher and

dispatcher sends it to queue file. after that dispatcher

allocates the request to available work proecessor to

process the request.

The work processor contains screen processor, abap

processor and flow logic.

ABAP processor process the abap code.

For each request in workprocessor contains user context and

roll area.

Roll area contains program name, variables, memory area,

dynamic variables, etc.

Regards,

Naresh.

***Please reward points if found useful