Introduction of the Server's 5.0 manual set called "New Features."

I have had a couple of people ask about the differences between 4.1 and 5.0. The following describes major new features. --Bill Text from the introduction of the Server's 5.0 manual set called "New Features." ================================================================================ This section highlights the major new features implemented in version 5.0 of Informix server products: Referential and entity integrity. New data integrity constraints allow you to specify a column or columns as representing a primary or foreign key of a table upon creation, and to establish dependencies between tables. Once specified, a parent-child relationship between two tables is enforced by the database server. Other constraints allow you to specify a default value for a column, or to specify a condition for a column that an inserted value must meet. Stored procedures. A stored procedure is a function written by a user using a combination of SQL statements and Stored Procedure Language (SPL). Once created, a procedure is stored as an object in the database in a compiled, optimized form, and is available to other users with the appropriate privileges. In a client/server environment, the use of stored procedures can significantly reduce network traffic. Dynamic SQL. Support is provided for the X/Open implementation of dynamic SQL using a system descriptor area. This support involves the new SQL statements ALLOCATE DESCRIPTOR, DEALLOCATE DESCRIPTOR, GET DESCRIPTOR, and SET DESCRIPTOR, as well as changes in the syntax of existing dynamic management statements. Optimizer enhancement. You can use the new SET OPTIMIZATION statement to instruct the database server to select a high or low level of query optimization. The default level of HIGH causes the database server to examine and select the best of all possible optimization strategies. Since this level of optimization may result in a longer-than-desired optimization time for some queries, you have the option of setting an optimization level of LOW. Relay module (INFORMIXNET only). The new Relay Module component of INFORMIXNET resides on the client machine in a distributed data processing environment and relays messages between an application development tool and an INFORMIX-OnLine or INFORMIX-SE database server through a network interface. The Relay Module allows version 5.0 application development tools to connect to a remote database server without the need to run an Informix database server process on the client. Fast indexing (INFORMIXOnLine only). The version 5.0 INFORMIXOnLine database server uses a new method of creating large indexes when you execute the CREATE INDEX statement. In this method, index entries are sorted prior to their insertion into the B+ tree structure, resulting in faster index creation. Two-phase commit (INFORMIXSTAR only). The new two-phase commit protocol allows you to manipulate data in multiple databases on multiple OnLine database servers within a single transaction. It ensures that transactions that span more than one OnLine database server are committed on an all-or-nothing basis. Support for optical media (INFORMIXOnLine/Optical only). A new product, INFORMIXOnLine/Optical, allows you to store and retrieve blob data using an optical storage subsystem. The new SQL statements and functions that support optical storage are described in the INFORMIX-OnLine/Optical User Manual. Support for transaction processing in the X/Open environment (INFORMIXTP/XA only). A new product, INFORMIXTP/XA, allows you to use the OnLine database server as a Resource Manager in conformance with the X/Open Preliminary Specification (April 1990), Distributed Transaction Processing: The XA Interface. The INFORMIX-TP/XA User Manual describes the changes in the behavior of existing SQL statements that manage transactions in an X/Open environment.

Excerpts from mail: 10-Feb-92 Introduction of the Server'.. William Daul@uunet.UU.NE (3974) > Two-phase commit (INFORMIXSTAR only). The new two-phase commit > protocol allows you to manipulate data in multiple databases on > multiple OnLine database servers within a single transaction. It > ensures that transactions that span more than one OnLine database > server are committed on an all-or-nothing basis. > ... > Support for transaction processing in the X/Open environment > (INFORMIXTP/XA only). A new product, INFORMIXTP/XA, allows you to use > the OnLine database server as a Resource Manager in conformance with > the X/Open Preliminary Specification (April 1990), Distributed > Transaction Processing: The XA Interface. The INFORMIX-TP/XA User > Manual describes the changes in the behavior of existing SQL > statements that manage transactions in an X/Open environment. Actually, two phase commit is part of the X/Open environment, so 2PC is provided in both Informix Star and Informix TP/XA. In the former case, you get globally consistent ("all-or-nothing") outcome among multiple Informix OnLine database servers working on a single transaction; in the later case, you get a globally consistent outcome among all XA-compliant databases working on a single transaction, which could be multiple OnLine database servers, multiple other RDBMS or a combination. To use Informix TP/XA, you also need to have an XA-compliant transaction manager (plug warning: such as Transarc's Encina product). -Mark -------------------------------------------------------------------- Mark Sherman Position: Senior Technical Marketing Executive Transarc Corp. Internet: mss@transarc.com 707 Grant Street +1-412-338-4420 Pittsburgh, PA 15219 Fax: +1-412-338-4404 --------------------------------------------------------------------