Caché Upgrade Checklists - InterSystems Documentation

Caché 5.2 Upgrade Checklist
3.1.3.4 SUSE Linux
SSL/TLS Support On Itanium
There is a known issue with the openssl-devel package supplied by InterSystems. Users should remove
the InterSystems-supplied package and install the version that comes with the operating system instead.
3.2 Developers
This section contains information of interest to those who have designed, developed and maintained
applications running on prior versions of Caché, particularly those that have made the transition to
Caché 5.2.
The items listed here are brief descriptions. In most cases, more complete descriptions are available
elsewhere in the documentation.
3.2.1 System Management Portal
There have been a number of changes and improvements to the system management portal since 5.1
was released. These are detailed in the administrator section.
3.2.2 IEEE 8-byte Floating Point Support
As noted in the Release Notes, this version of Caché now supports operations on floating-point data
in the IEEE-754 format. The Objectscript function that does this conversion is $DOUBLE; the Caché
datatype class for it is %Library.Double.
In addition, the SQL SystemDataType mapping has been changed. In previous releases, the SQL
datatypes DOUBLE and DOUBLE PRECISION were mapped to %Library.Float (and implemented
as ObjectScript numbers). In this release, they are mapped to %Library.Double (and implemented
using the $DOUBLE function).
The major difference between the two representations lies in the achievable numeric precision. Caché
represents numbers to 18 decimal digits of precision. IEEE-754 uses a binary mantissa of 53 bits,
resulting in a decimal precision of 15 decimal digits (actually about 15.3). There are two effects of
this that developers must be aware of:
• Those applications obtaining floating-point data via an ODBC or JDBC interface will see the
exact value of the number that was transmitted in their application. Previously, the conversion to
an ObjectScript numeric value may have resulted in a slightly different value being used internally.
24 Caché Upgrade Checklists