oracle

1. Nadar Saraswati college of arts & science
. RDBMS
Oracle & Microsoft SQL server
. B.kohila
. M.sc information technology

2. Microsoft SQL Server and Oracle Compared
 This chapter contains information comparing the Microsoft SQL Server database
and the Oracle database. It contains the following sections:
 Schema Migration
 Data Types
 Data Storage Concepts
 Data Manipulation Language

3. Schema Migration
 The schema contains the definitions of the tables, views, indexes, users,
constraints, stored procedures, triggers, and other database-specific objects. Most
relational databases work with similar objects.
 The schema migration topics discussed here include the following:
 Schema Object Similarities
 Schema Object Names
 Table Design Considerations

4. Schema Object Similarities
 There are many similarities between schema objects in Oracle and schema
objects in Microsoft SQL Server. However, some schema objects differ between
these databases, as shown in the following table:

5. Schema Object Names
 Reserved words differ between Oracle and Microsoft SQL Server. Many Oracle
reserved words are valid object or column names in Microsoft SQL Server. For
example, DATE is a reserved word in Oracle, but it is not a reserved word in
Microsoft SQL Server. Therefore, no column is allowed to have the name DATE in
Oracle, but a column can be named DATE in Microsoft SQL Server. Use of
reserved words as schema object names makes it impossible to use the same
names across databases.

6. Table Design Considerations
 This section discusses the many table design issues that you need to consider
when converting Microsoft SQL Server databases to Oracle. These issues are
discussed under the following headings:
 Data Types
 Entity Integrity Constraints
 Referential Integrity Constraints
 Unique Key Constraints
 Check Constraints

7. Data Types
 This section describes conversion considerations for the following data types:
 DATETIME Data Types
 IMAGE and TEXT Data Types (Binary Large Objects)
 Microsoft SQL Server User-Defined Data Types

8.  DATETIME Data Types
 The date/time precision in Microsoft SQL Server is 1/300th of a second. Oracle has
the data type TIMESTAMP which has a precision of 1/100000000th of a second.
Oracle also has a DATE data type that stores date and time values accurate to one
second. SQL Developer has a default mapping to the DATE data type.
 For applications that require finer date/time precision than seconds, the
TIMESTAMP data type should be selected for the data type mapping of date data
types in Microsoft SQL Server. The databases store point-in-time values for DATE
and TIME data types.