Component Integration Services presents tables to a client application as if all the data in the tables were stored locally. Remote tables are mapped to local proxy tables which hold metadata. The ability to access remote (or external) tables as if they were local is a hallmark of Component Integration Services..
Remote tables are mapped to local proxy tables which hold metadata. Internally, when a query involving remote tables is executed, the storage location is determined, and the remote location is accessed so that data can be retrieved.
To achieve location transparency, tables must first be mapped to their corresponding external locations.
The server class associated with the remote object. For each server class, there are separate access methods that handle all interaction between SAP ASE and remote servers of the same class and object type.
The object type
A server class must be assigned to each server when it is added using sp_addserver. Server classes determine the access method used to interact with the remote server.
ASEnterprise – used if the server is SAP ASE. This is the default server class.
ASAnywhere – used if the server is SQL Anywhere version 6.0 or later. This server class should be used for SAP IQ versions earlier than SAP IQ 12.5.
ASIQ – used if the server is SAP IQ version 12.5 and later.
local – the local server. There can be only one.
direct_connect – indicates that the server is an Open Server™ application that conforms to the interface requirements of a DirectConnect™ server. For access to Microsoft SQL Server, DB2, Oracle, or Informix, you must use a DirectConnect server.
sds – indicates that the server conforms to the interface requirements of a Specialty Data Store.
RPCServer – indicates that a server can only handle RPCs. It does not accept SQL statements, transaction control statements, or anything else.
The server presents a number of object types to client applications as if they were local tables.
table – the object in a remote server of any class is a relational table. This is the default type.
view – the object in a remote server of any class is a view. Component Integration Services treats views as if they were local tables without any indexes.
remote procedure – the object in a remote server of any class is a remote procedure. Component Integration Services treats the result set from the remote procedure as a read-only table.
file – the object is an individual file within a file system.
directory – the object is a file system directory.
The interface between the server and remote servers is handled by the Open Client software, Client-Library™.
The Client-Library features that are used to implement the interface are dependent upon the class of server with which Component Integration Services is interacting.
For example, if the server class is direct_connect, a number of features such as cursor and dynamic requests are used.
Remote server addition to directory services
Remote server definition
Remote server login information
Remote object definition
Before accessing remote tables with Component Integration Services, you must either have access to LDAP directory services, or an interfaces file (sql.ini file on Windows platforms).
Remote servers are defined by means of the stored procedure sp_addserver. This procedure is documented in the Reference Manual.
Once you have configured the remote server, you must provide login information. By default, Component Integraiton Services uses the names and passwords of SAP ASE clients whenever it connects to a remote server on behalf of those clients. However, this default can be overridden using sp_addexternlogin, which allows a system administrator to define the name and password for each user who connects to a remote server.
Using connect to server_name, you can verify that the server configuration is correct. This command establishes a passthrough mode connection to the remote server. Passthrough mode allows clients to communicate with remote servers in native syntax. This passthrough mode remains in effect until you issue a disconnect command.
Once you have configured a remote server, you cannot access objects in that remote server as tables until a mapping between them and a local object (proxy table) has been established.
You can create new tables on remote servers, and you can define the schema for an existing object in a remote server. The procedures for both are similar.