topic Re: question in Application Development and Automation Discussions

question

Former Member — Wed, 07 Mar 2007 10:52:16 GMT

what is buffer

Re: question

Former Member — Wed, 07 Mar 2007 10:53:43 GMT

a buffer is a tempopray storage space ., where records accessed from the database are temporarily stored.

Regards,

Ravi

Re: question

Former Member — Wed, 07 Mar 2007 10:55:35 GMT

Refer

http://help.sap.com/saphelp_nw2004s/helpdata/en/bc/4a813b680c250fe10000000a114084/content.htm

Regards,

santosh

Re: question

Former Member — Wed, 07 Mar 2007 11:01:08 GMT

Hi,

Buffer is a temporary storage location for data in Application Server.

The data which is retrieved from the database is stored in buffer for some time, next time when u want to access the same data then it is retrieved from the buffer..need not to go database..

there are 3 types of buffers:

Generic Buffering

Full bufferig : Stores entire table data

Single record Buffering: Stores particular record

Re: question

Former Member — Wed, 07 Mar 2007 11:07:28 GMT

refer link,

http://help.sap.com/saphelp_sm40/helpdata/en/c4/3a6dbb505211d189550000e829fbbd/frameset.htm

It will give you the details about buffers as well as types of buffers.

There are seven main groups of buffers found in the shared memory.

Repository Buffers

Table Buffers

Program Buffer

SAPgui Buffers

Roll and Paging Buffers

SAP Calendar Buffer

SAP Cursor Cache

Reward if useful.

Re: question

Former Member — Wed, 07 Mar 2007 11:29:04 GMT

Hai vrushali....

Unlike application servers and presentation servers, there is only one database server in your system. You should therefore aim to reduce the database load as much as possible..

You can considerably reduce the time required to access data by buffering it in the application server table buffer(a temparary memory in Application server)

Whether a table can be buffered or not depends its technical attributes in the ABAP Dictionary. There are three buffering types:

Resident buffering (100%) The first time the table is accessed, its entire contents are loaded in the table buffer.

Generic buffering In this case, you need to specify a generic key (some of the key fields) in the technical settings of the table in the ABAP Dictionary. The table contents are then divided into generic areas. When you access data with one of the generic keys, the whole generic area is loaded into the table buffer. Client-specific tables are often buffered generically by client.

Partial buffering (single entry) Only single entries are read from the database and stored in the table buffer.

When you read from buffered tables, the following happens:

1.An ABAP program requests data from a buffered table.

2.The ABAP processor interprets the Open SQL statement. If the table is defined as a

buffered table in the ABAP Dictionary, the ABAP processor checks in the local buffer

on the application server to see if the table (or part of it) has already been buffered.

3.If the table has not yet been buffered, the request is passed on to the database. If the data exists in the buffer, it is sent to the program.

4.The database server passes the data to the application server, which places it in the table buffer.

5.The data is passed to the program.

You should buffer the following types of tables:

Tables that are read very frequently

Tables that are changed very infrequently

Relatively small tables (few lines, few columns, or short columns)

Tables where delayed update is acceptable.

Suresh......