topic Re: Table difference in Application Development and Automation Discussions

Table difference

Former Member — Tue, 25 Jul 2006 07:15:22 GMT

hi all

What is different types of tables?

and difference between tables

Thanks and Regards

Suresh

Re: Table difference

Former Member — Tue, 25 Jul 2006 07:17:20 GMT

Hi Suresh,

There are three tables.

Transparent Table:

Exists with the same structure both in dictionary as well as in database exactly with the same data and fields.

Pooled Table:

Pooled tables are logical tables that must be assigned to a table pool when they are defined. Pooled tables are used to store control data. Several pooled tables can be cominied in a table pool. The data of these pooled tables are then sorted in a common table in the database.

Cluster Table:

Cluster tables are logical tables that must be assigned to a table cluster when they are defined. Cluster tables can be used to strore control data. They can also be used to store temporary data or texts, such as documentation.

A transparent table is a table that stores data directly. You can read these tables directly on the database from outside SAP with for instance an SQL statement.

Transparent table is a one to one relation table i.e. when you create one transparent table then exactly same table will create in data base and if is basically used to store transaction data.

A clustered and a pooled table cannot be read from outside SAP because certain data are clustered and pooled in one field.

One of the possible reasons is for instance that their content can be variable in length and build up. Database manipulations in Abap are limited as well.

But pool and cluster table is a many to one relationship table. This means many pool table store in a database table which is know as table pool.

All the pool table stored table in table pool does not need to have any foreign key relationship but in the case of cluster table it is must. And pool and cluster table is basically use to store application data.

Table pool can contain 10 to 1000 small pool table which has 10 to 100 records. But cluster table can contain very big but few (1 to 10) cluster table.

For pool and cluster table you can create secondary index and you can use select distinct, group for pool and cluster table. You can use native SQL statement for pool and cluster table.

A structure is a table without data. It is only filled by program logic at the moment it is needed starting from tables.

A view is a way of looking at the contents of tables. It only contains the combination of the tables at the basis and the way the data needs to be represented. You actually call directly upon the underlying tables.

Hope this will help.

Regards,

Re: Table difference

Former Member — Tue, 25 Jul 2006 07:17:22 GMT

If are askin about internal Tables :

STANDARD TABLE

Effect

Defines the table as a standard table. Key access to a standard table uses a linear search. This means that the timne required for a search is in linear relation to the number of table entries.

You should use index operations to access standard tables.

For the sake of compatibility, you can use TABLE as a synonym of STANDARD TABLE.

Alternative 2

SORTED TABLE

Effect

Defines the table as one that is always saved correctly sorted. Key access to a sorted table uses a binary key. If the key is not unique, the system takes the entry with the lowest index. The runtime required for key access is logarithmically related to the number of table entries.

You can also access sorted tables by index operations. When you insert using an index, the system checks to ensure that the sort sequence has been correctly maintained. For this reason, it takes longer than inserting entries in a standard table. As a rule, you should only access sorted tables using their key.

Alternative 3

HASHED TABLE

Effect

Defines the table as one that is managed with an internal hash procedure. You can imagine a hashed table as a set, whose elements you can address using their unique key. Unlike standard and sorted tables, you cannot access hash tables using an index. All entries in the table must have a unique key. Access time using the key is constant, regardless of the number of table entries.

You can only access a hashed table using the generic key operations or other generic operations ( SORT, LOOP, and so on). Explicit or implicit index operations (such as LOOP ... FROM oe INSERT itab within a LOOP) are not allowed.

Alternative 4

INDEX TABLE

Effect

Standard and sorted tables belong to the generic class index tables. An index table is one that you can access using an index. You can currently only use the table type INDEX TABLE to specify the type of generic parameters in a FORM or a FUNCTION. Hashed tables are not index tables, and cannot therefore be passed to parameters defined as INDEX TABLE.

Alternative 5

ANY TABLE

Effect

Like INDEX TABLE, you use ANY TABLE to specify the type of any generic table parameter. The set of permitted operations for a table with type ANY TABLE consists of the intersection of all permitted operations for STANDARD, SORTED and HASHED TABLEs, and so is identical to the set of operations permitted for hashed tables.

Note in particular that you cannot use index access for tables with this type.

BR, JAcek

Message was edited by: Jacek Slowikowski

Re: Table difference

Former Member — Tue, 25 Jul 2006 07:30:13 GMT

Hi Suresh,

I'm not Sure what tables you are asking for (Internal Tables or Database tables) anyway let me give you some information regarding both.

Database Table,

This is of Three Types

Transaparent Table:

Tables can be defined independently of the database in the ABAP Dictionary. The fields of the table are defined with their (database-independent) data types and lengths.

When the table is activated, a physical table definition is created in the database for the table definition stored in the ABAP Dictionary.

Pool Tables:

A table in the database in which all records from the pooled tables assigned to the table pool are stored corresponds to a table pool.

Cluster table:

Several logical data records from different cluster tables can be stored together in one physical record in a table cluster.

A cluster key consists of a series of freely definable key fields and a field (Pageno) for distinguishing continuation records. A cluster also contains a long field (Vardata) that contains the contents of the data fields of the cluster tables for this key. If the data does not fit into the long field, continuation records are created. Control information on the structure of the data string is still written at the beginning of the Vardata field.

I have rfefered this from ABAP Documentation and have provided the Link Below for you to Look into Detail.

<a href="http://help.sap.com/saphelp_46c/helpdata/en/cf/21f083446011d189700000e8322d00/content.htm">http://help.sap.com/saphelp_46c/helpdata/en/cf/21f083446011d189700000e8322d00/content.htm</a>

Internal Table,

Standard tables

This is the most appropriate type if you are going to address the individual table entries using the index. Index access is the quickest possible access. You should fill a standard table by appending lines (ABAP APPEND statement), and read, modify and delete entries by specifying the index (INDEX option with the relevant ABAP command). The access time for a standard table increases in a linear relationship with the number of table entries. If you need key access, standard tables are particularly useful if you can fill and process the table in separate steps. For example, you could fill the table by appending entries, and then sort it. If you use the binary search option with key access, the response time is logarithmically proportional to the number of table entries.

Sorted tables

This is the most appropriate type if you need a table which is sorted as you fill it. You fill sorted tables using the INSERT statement. Entries are inserted according to the sort sequence defined through the table key. Any illegal entries are recognized as soon as you try to add them to the table. The response time for key access is logarithmically proportional to the number of table entries, since the system always uses a binary search. Sorted tables are particularly useful for partially sequential processing in a LOOP if you specify the beginning of the table key in the WHERE condition.

Hashed tables

This is the most appropriate type for any table where the main operation is key access. You cannot access a hashed table using its index. The response time for key access remains constant, regardless of the number of table entries. Like database tables, hashed tables always have a unique key. Hashed tables are useful if you want to construct and use an internal table which resembles a database table or for processing large amounts of data.

This is also been refered from ABAP Help for more details refer the link below,

<a href="http://help.sap.com/saphelp_46c/helpdata/en/fc/eb35de358411d1829f0000e829fbfe/content.htm">http://help.sap.com/saphelp_46c/helpdata/en/fc/eb35de358411d1829f0000e829fbfe/content.htm</a>

Path(BC-ABAP PROGRAMMING->PROCESSING LARGE VOLUME OF DATA->INTERNAL TABLES).

Cheers,

Prashanth