IBM i series Handbook page 487

Operating System/400 (5722-SS1)
server mode is also provided that allows developers to write applications that perform
database serving for multiple users.
Distributed Database Support
OS/400 supports distributed relational database, SQL, and a wide range of data types,
including date and time. This support allows read and write access from an iSeries server to
another iSeries server or to any other DB2 family member. The CPI for database is
Structured Query Language (SQL). Customer investment in data is protected by this
distributed support, which allows data connectivity across platforms. Interactive access to
distributed database is possible using the prompted facilities of interactive SQL (ISQL). Both
are available in the separate licensed program DB2 Query Manager and SQL Development
Kit for iSeries (5722-ST1). Distributed file access between an iSeries server, CICS, PCs,
System/36, and System/38 is also available using Distributed Data Management, included in
OS/400. This support allows access to remote files by applications using file and database
interfaces.
Existing DB2 UDB for iSeries SQL applications, including applications using iSeries Client
Access SQL interfaces, can be easily modified with this API to perform database requests on
other databases. The data is returned to the application for processing as if it had come from
DB2 UDB for iSeries. With this support, the programmer's interface is the same whether
Distributed Relational Database Architecture (DRDA) or the SQL Client Integration API is
used.
Database SQL Portability
DB2 UDB for iSeries adds Java to the list of languages in which stored procedures can be
written. Stored procedures are an efficient method of performing SQL processing across a
network since one procedure can run multiple statements and logic to control statement flow
with minimal network traffic. Stored procedures written in Java are methods in Java classes.
Once a stored procedure is created and registered, and the Java classes are placed in the
correct file location, they can be called from any language that can execute SQL statements.
This includes running from remote systems with ODBC or DRDA. DB2 UDB for iSeries
performs the necessary setup to enable a Java virtual machine to run the methods, and
performs the conversion between SQL types and Java objects. DB2 CLI, the call level
interface for running SQL statements from ILE programming languages, is now more
compatible with the ODBC standard. This makes porting applications written to the popular
ODBC standard much easier.
Access Paths
Access paths may be defined for files to allow access in either keyed or arrival sequence
order. Access paths are maintained when a change to the data occurs, allowing multiple
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Operating System/400 (5722-SS1)