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A table is a set of rows. Each row in a table has the same number of columns and contains a value for each column.

Table Types

Table type

Description

Base table

System tables and all tables containing application data are base tables. Base tables are saved permanently.

Results table

The database system creates unnamed result tables when a SELECT statement is executed and then deletes them at the end of the session.

The database system creates named result tables when a DECLARE CURSOR statement is executed.

Join table

A join table is a special results table that the database system creates when two or more tables are linked.

System Table

A system table is a base table that contains system information (information about the database objects, states, statistics, monitor data; Loader system tables).

Temporary table

A temporary table is a special base table that the database system deletes at the end of the session. Temporary tables belong to the TEMP schema.

View Table

A view table is derived from a base table and its definition is saved permanently. View tables themselves contain no data, they only provide a view of the data.

The database system automatically increases and decreases the size of tables without the administrator having to take any action. The database system uses database-internal striping to distribute the data in a table evenly across all the data volumes. You can neither influence how the data is distributed across the data volumes nor can you find out which tables are saved in which data volumes.

Table Properties
Columns

Property

Description (Links to SQL Reference Manual)

Name

Column Name (column_name)

Data Type

Data Type (data_type)

Dim

Dimension

Maximum number of characters

Code Attribute

Code attribute

Key

If you select this option, you add this column to the primary key.

Key Definition (key_definition)

All columns in the primary key must be NOT NULL columns.

You cannot use any columns of the LOB data type in the primary key.

The database ensures that no NULL value exists in the key column and that no two data records in the table have the same values in all key columns.

Not Null

If you select this option, the value for this column cannot be a NULL value.

Column Attributes (column_attributes)

Constraints

Property

Description (Links to SQL Reference Manual)

Name

Constraint Name (constraint_name)

Definition

CONSTRAINT Definition (constraint_definition)

Indexes

Property

Description (Link to SQL Reference Manual)

Index name

Index Name (index_name)

In Index

Indicates whether a column belongs to the index

Sort

Sort sequence

Name

Column name

Data Type

Column data type

You cannot use LOB columns in an index.

Unique

Indicates whether the values for this columns must be unique

UNIQUE Definition (unique_definition)

Disabled

Indicates whether the index is deactivated

Usage Count

Indicates how often the system has used the index

Bad

Indicates whether the index is damaged

Foreign Keys

Property

Description (Link to SQL Reference Manual)

Name

Foreign key name

Referencing Columns

Referencing column

Referential CONSTRAINT Definition (referential_constraint_definition)

Reference Schema

Schema to which the table with the column that is referenced belongs

Reference Table

Table to which the column that is referenced belongs

Reference Column

Column which is referenced

Rule

Rule for behavior of the table referenced if a data record is deleted in the referencing table

DELETE Rule (delete_rule)

Optimizer Statistics

Property

Description

Columns and Indexes

Columns and indexes

Distinct Values

Estimated number of lines in the table

Page Count

Estimated table size (in pages)

This size affects which search strategy is selected by the system.

More information: SQL Optimizer, Search Strategies

Last Statistics Update

Time of the last statistics update

Table: Miscellaneous

Property

Description (Link to SQL Reference Manual)

Sample Type

Sample type that the system uses for estimating the statistics for the SQL Optimizer

More information:

Sample Data

Sample value (in data records or percent) that the system uses for estimating the statistics for the SQL Optimizer

Table Size

Information about the current table size

Clustered

Only for SAP NetWeaver BI systems with BW Feature Pack

This attribute has the result that the database does not distribute pages in single blocks of 8 KB across all volumes, rather, where possible it saves the contents in larger, contiguous blocks in the data volumes.

More information:

Virtual Primary Key

Only for SAP NetWeaver BI systems with BW Feature Pack

For tables which have no primary key, the system forms a primary key internally and sets the Clustered attribute. Columns which the system uses for the primary key do not need to have the UNIQUE attribute.

Packed

Only for SAP NetWeaver BI systems with BW Feature Pack

The system stores numerical columns that are not key columns in compressed form.