Table Type -- Urgent

[Former Member]

Hi,

What are table type and what are the uses??

Will it improve the performance and memory cost??

Regards

Jiku

[former_member188829]

Hi,

http://help.sap.com/saphelp_nw04/helpdata/en/90/8d7304b1af11d194f600a0c929b3c3/frameset.htm

[Former Member]

Hi Jiku,

If its Different Dictionary Tables that you want to know about then please refer to the below reply:

Table pools (pools) and table clusters (clusters) are special table types in the ABAP Dictionary. The data from several different tables can be stored together in a table pool or table cluster. Tables assigned to a table pool or table cluster are referred to as pooled tables or cluster 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.

The definition of a pool consists essentially of two key fields (Tabname and Varkey) and a long argument field (Vardata).

Table Clusters 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.

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Cheers,

Chaitanya.

[Former Member]

hi!!!!!!!!!!!!

Standard Internal Tables

1.Standard tables have a linear index.

2. You can access them using either the index or the key.

3. If you use the key, the response time is in linear relationship to the number of table entries. The key of a standard table is always non-unique, and you may not include any specification for the uniqueness in the table definition.

advantage:

This table type is particularly appropriate if you want to address individual table entries using the index. This is the quickest way to access table entries. To fill a standard table, append lines using the (APPEND) statement. You should read, modify and delete lines by referring to the index (INDEX option with the relevant ABAP command). The response time for accessing a standard table is in linear relation to the number of table entries. If you need to use key access, standard tables are appropriate if you can fill and process the table in separate steps.

For example, you can fill a standard table by appending records and then sort it. If you then use key access with the binary search option (BINARY), the response time is in logarithmic relation to

the number of table entries

Sorted Internal Tables

Sorted tables are always saved correctly sorted by key. They also have a linear key, and, like standard tables, you can access them using either the table index or the key. When you use the key, the response time is in logarithmic relationship to the number of table entries, since the system uses a binary search. The key of a sorted table can be either unique, or non-unique, and you must specify either UNIQUE or NON-UNIQUE in the table definition. Standard tables and sorted tables both belong to the generic group index tables.

This table type is particularly suitable if you want the table to be sorted while you are still adding entries to it. You fill the table using the (INSERT) statement, according to the sort sequence defined in the table key. Table entries that do not fit are recognised before they are inserted. The response time for access using the key is in logarithmic relation to the number of

table entries, since the system automatically uses a binary search. Sorted tables are appropriate for partially sequential processing in a LOOP, as long as the WHERE condition contains the beginning of the table key.

Hashed Internal Tables

Hashes tables have no internal linear index. You can only access hashed tables by specifying the key. The response time is constant, regardless of the number of table entries, since the search uses a hash algorithm. The key of a hashed table must be unique, and you must specify UNIQUE in the table definition.

This table type is particularly suitable if you want mainly to use key access for table entries. You cannot access hashed tables using the index. When you use key access, the response time remains constant, regardless of the number of table entries. As with database tables, the key of a hashed table is always unique. Hashed tables are therefore a useful way of constructing and

using internal tables that are similar to database tables.

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[Former Member]

Can anyone tell me what is the advantage in using a table type in a function module as exporting or importing parameter instead of declaring in Tables tab.

[Former Member]

hi!!!!!!!!!!!1

if u are declaring table type in tables tab , then that could be used as exporting as well as importing parameter ...

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[Former Member]

Hi

Table types: Describe the structure of an internal table

Analogous to the predefined ABAP types such as C or I , one may define user-defined types in the dictionary.

The following user-defined types are allowed

Data elements: Describe an elementary type by defining the data type, length and possibly decimal places.

Structures: Consist of components that can have any type.

Table types: Describe the structure of an internal table.

Elaboration on the type categories.

There are three different type categories in the ABAP Dictionary:

Data elements (elementary types) Elementary types have no structure. They describe the data type attributes (such as given Dictionary data type, number of places) and information that is relevant for the screen (such as title) of unstructured data objects (variables/fields).

Structures (structured types) Structured types describe the structure and functions of any structured data objects, that is of data structures with components of any type. A component can be a field with an elementary type or can itself be a structure. A table can also be used as a component in a structure. A database table always has a structure and is therefore implicitly a structured type. However, the fields of a database table can only have an elementary type.

Table types Table types describe the structure and functions of internal tables in the ABAP program. Their rows can have any row type. Table types with elementary row type therefore can be defined just the same as multi-dimensional table types (table types with a table type as row type) or table types using structures with table-like components.

Elaboration on each of the definitions

A transparent table is automatically created on the database when it is activated in the ABAP Dictionary. At this time the database-independent description of the table in the ABAP Dictionary is translated into the language of the database system used.

The database table has the same name as the table in the ABAP Dictionary. The fields also have the same name in both the database and the ABAP Dictionary. The data types in the ABAP Dictionary are converted to the corresponding data types of the database system.

The order of the fields in the ABAP Dictionary can differ from the order of the fields on the database. This permits you to insert new fields without having to convert the table. When a new field is added, the adjustment is made by changing the database catalog (ALTER TABLE). The new field is added to the database table, whatever the position of the new field in the ABAP Dictionary.

Tables can also reside on the database as Pooled tables or cluster tables

Pooled Tables: Different tables which are not linked to each other with a common key can be combined into a Table Pool. The tables contained within this pool are called Pooled Tables. A table pool is stored in the database a simple table. The table's data sets contain, in separate fields, the actual key for the data set to be stored, the name of the pooled table and the contents of the data set to be stored.

Using this schema, several logical tables are combined into a single real database table. Although the data structure of each set is lost during the write to the table pool, it is restored during the read by the ABAP/4 Data Dictionary. The ABAP/4 Data Dictionary utilizes its meta-data to accomplish this.

Since information must be prepared (defined) within the ABAP/4 Data Dictionary when it is read or written to (or accessed), this process itself defines these as not transparent tables

Cluster Tables: Occasionally, several tables may be linked by a common key. The ABAP/4 Data Dictionary can also combine these tables into a single table. Each data set of the real table within the database contains a key and in a single data field, several data sets of the subsequent table for this key.

As mentioned above, these table types require special data handling, therefore they are not transparent tables.

[Former Member]

hi,

use following link:

http://help.sap.com/saphelp_nw04/helpdata/en/fc/eb366d358411d1829f0000e829fbfe/content.htm

please reward if useful.

[Former Member]

hi,

1) Standard Internal Tables

Standard tables have a linear index. You can access them using either the index or the key. If you use the key, the response time is in linear relationship to the number of table entries. The key of a standard table is always non-unique, and you may not include any specification for the uniqueness in the table definition.

This table type is particularly appropriate if you want to address individual table entries using the index. This is the quickest way to access table entries. To fill a standard table, append lines using the (APPEND) statement. You should read, modify and delete lines by referring to the index (INDEX option with the relevant ABAP command). The response time for accessing a standard table is in linear relation to the number of table entries. If you need to use key access, standard tables are appropriate if you can fill and process the table in separate steps. For example, you can fill a standard table by appending records and then sort it. If you then use key access with the binary search option (BINARY), the response time is in logarithmic relation to

the number of table entries.

2) Sorted Internal Tables

Sorted tables are always saved correctly sorted by key. They also have a linear key, and, like standard tables, you can access them using either the table index or the key. When you use the key, the response time is in logarithmic relationship to the number of table entries, since the system uses a binary search. The key of a sorted table can be either unique, or non-unique, and you must specify either UNIQUE or NON-UNIQUE in the table definition. Standard tables and sorted tables both belong to the generic group index tables.

This table type is particularly suitable if you want the table to be sorted while you are still adding entries to it. You fill the table using the (INSERT) statement, according to the sort sequence defined in the table key. Table entries that do not fit are recognised before they are inserted. The response time for access using the key is in logarithmic relation to the number of

table entries, since the system automatically uses a binary search. Sorted tables are appropriate for partially sequential processing in a LOOP, as long as the WHERE condition contains the beginning of the table key.

3)Hashed Internal Tables

Hashes tables have no internal linear index. You can only access hashed tables by specifying the key. The response time is constant, regardless of the number of table entries, since the search uses a hash algorithm. The key of a hashed table must be unique, and you must specify UNIQUE in the table definition.

This table type is particularly suitable if you want mainly to use key access for table entries. You cannot access hashed tables using the index. When you use key access, the response time remains constant, regardless of the number of table entries. As with database tables, the key of a hashed table is always unique. Hashed tables are therefore a useful way of constructing and

using internal tables that are similar to database tables.

4)Index Tables

Index table is only used to specify the type of generic parameters in a FORM or FUNCTION. That means that you can't create a table of type INDEX.

Internal tables are not DB tables. Standard and Sorted tables in combined are basically called as Index tables and there nothing else

ANY TABLE

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Index Tables Hashed Table

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Standard Table Sorted Table

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