HP System Dictionary/XL General Reference Manual Vol 1 (32256-90004)

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2.
Opening the Dictionary
Opening the dictionary is the procedure that defines a new access path to a dictionary you specify. You
establish an access path with the information you specify in the parameters of the SDOpen intrinsic or the
DEFINE command in SDMAIN. This information includes the dictionary open mode, scope, name mode,
domain, and version that you are using.
After you establish an access path, you may modify it by using the SDMAIN DEFINE command or the
appropriate dictionary intrinsic to switch the current name mode, scope, domain, or version. This
procedure takes less time and uses fewer system resources than closing and re-opening the dictionary.
This is especially true from the Exclusive Customization mode, as any changes made to the dictionary
structure would be automatically incorporated at that time through the restructuring process. Closing the
dictionary and calling SDOpen or specifying the DEFINE command again requires an allocation of system
resources, which can degrade the performance of System Dictionary.
It is also possible to define multiple access paths to a dictionary within the same session, that is, you may
call SDOpen repeatedly without closing previous OPENs. This may be useful, for example, for copying
definitions from one domain to another. Multiple OPENs are not generally recommended, however, as
serious problems can occur if they are not done correctly.
Remote Dictionary Access
System Dictionary includes a feature that allows remote dictionaries. This capability allows you to create,
access, and maintain dictionaries on systems located at remote sites without having to actually be there. A
company, then, can create and maintain standard dictionaries in its offices worldwide from a central
location, likely the corporate offices. You can also access the remote dictionaries locally, and modify them to
include local definitions as needed, but you will most likely use them as "read only" dictionaries,
implementing company standards and definitions throughout its offices.
For more information on how to use remote dictionaries, see the DEFINE command of the HP System
Dictionary/XL SDMAIN Reference Manual or the SDOpen intrinsic of the HP System Dictionary/XL
Intrinsics Reference Manual.
Compiled Dictionary
System Dictionary includes two types of dictionaries which containmetadata:
• Master Dictionaries. A master dictionary consists of a TurboIMAGE database that can be accessed by
all System Dictionary intrinsics and SDMAIN commands. Because of its complexity, however, the re-
sponse time while using master dictionaries may be inadequate for some subsystems, especially those
that must read from the dictionary at run-time.
• Compiled Dictionaries. A compiled dictionary contains metadata extracted from a master dictionary.
Like a compiled program, a compiled dictionary cannot be modified. A compiled dictionary is therefore
a read-only dictionary that can be accessed by those System Dictionary intrinsics and commands that
only read dictionary metadata.
Compiled dictionaries provide faster dictionary read access and are intended to be used by subsystems and
applications that need only to read the metadata. A compiled dictionary is less complex than a master
dictionary and is compacted into one or more flat files. Therefore, it requires less disc storage space and
provides a more efficient means of transporting dictionary data to other groups and accounts in the same
system, or other systems in a distributed network. For more information about compiled dictionaries, see
the SDUTIL utility of the HP System Dictionary/XL General Reference Manual, Volume 2.