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A table is a set of rows.
A row is an ordered list of values.
The row is the smallest unit of data that can be inserted in or deleted from a
table.
Each row in a table has the same number of columns and
contains a value for each column.
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A base table is a table that usually has
a permanent memory representation and description.
It is also possible to create a base table that has only a temporary memory
representation and description. This table and its description are implicitly
dropped when a user stops working with the database system (end of
session).
· A result table is a temporary table that is generated from one or more base table(s) by means of a SELECT statement (result table name).
· A temporary table has the owner TEMP. Temporary tables only exist during a database session of one user. When the session ends, the table and its content are deleted.
· A view table is a table derived from base tables. A view table has a permanent description in the form of a SELECT statement.
· AJoin table links tables (Join, Join Table (joined_table), JOIN Predicate (join_predicate))
Each table has a name that is unique within the whole database system. The names of existing tables can be used to name result tables. The original tables, however, cannot be accessed as long as the result tables exist.
If a table name was defined without an owner, the catalog sections (part catalogs) are searched in the following order to locate the specified table name:
1. Catalog part of the current user
2. Set of PUBLIC synonyms
3. Catalog part of the DBA who created the current user
4. Catalog part of the SYSDBA
5. Catalog part of the owner of the system tables
.
A table of another user can only be used if the relevant privileges have been granted.
See also: