abap basics

[Former Member]

what are hashed internal tables?

[Former Member]

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.

Check these for more details.

http://help.sap.com/saphelp_nw70/helpdata/en/fc/eb35de358411d1829f0000e829fbfe/content.htm

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

Regards,

Maha

[Former Member]

Hi,

These are non index tables, where as Standard tables and sorted tables are index tables. The records are present based on the hash algorithm. Operation using field symbols is not possible in these tables.

Thanks,

Kasiraman R

[former_member188829]

Hi,

Check this link..

http://www.sap-img.com/abap/what-is-use-of-using-hashed-table.htm

[Former Member]

hi,

Internal tables provide a means of taking data from a fixed structure and storing it in working memory in ABAP. The data is stored line by line in memory, and each line has the same structure. In ABAP, internal tables fulfill the function of arrays. Since they are dynamic data objects, they save the programmer the task of dynamic memory management in his or her programs. You should use internal tables whenever you want to process a dataset with a fixed structure within a program.

Hashed tables have no linear index. You can only access a hashed table using its key. The response time is independent of the number of table entries, and is constant, since the system access the table entries using a hash algorithm. The key of a hashed table must be unique. When you define the table, you must specify the key as UNIQUE.

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.

Hope this is helpful, Do reward.