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Software
Source Announces
The Release of VsamEx 6.0
Software
Source’s award winning high speed database engine now supports
sparse fields and dynamic data definitions. With a small footprint (170k),
multi user record locking and industrial strength reliability - it is
time tested technology! VsamEx[treme] exports an easy intuitive API
for VB6 and .NET. It is used by many large Banks, Oil Companies, Insurance
Agencies.
Royalty Free!
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If
it Looks like a Nail...
If
all you have is a hammer, everything looks like a nail.
When it comes to managing data for your application, a SQL
Server or Jet databases are often appropriate but for some
jobs they can be overkill - especially when disk space and
performance are important factors. In those cases, you do
not need a database, you need the "Un-Database"
- VsamEx[treme], a
fast ISAM database engine from Software Source. With
only a 150k footprint, it’s perfect for embedded &
Internet distribution!
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The
VSAM part of VsamEx[treme]
stands for Virtual [Indexed] Sequential Access Method (ISAM),
a time honored access method for record data, especially
when performance is important. While there are many implementations
of the ISAM concept, VsamEx[treme] is one of the fastest
and most reliable. This is especially true when you consider
that unlike most ISAM implementations, it handles variable
length records. This is an important factor when your dataset
design includes records that vary greatly in size.
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The
VsamEx[treme]
ISAM comes as a DLL, ActiveX OCX, or Link Library.
Whatever language your application is coded in, the VsamEx[treme] ISAM
may be linked to it. For example, in Visual Basic you just
include the .BAS file and bingo; all of the VsamEx[treme]
ISAM functions are available as extensions to VB. In
addition, there is a 100% compatible version for Linux
that maintains Binary compatible datasets.
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All
Fields Are Not Equal...
The
VsamEx[treme]
ISAM also provides the ability to add and delete fields
dynamically. This means that as your database design evolves,
you can change the record structure on the fly, without
rebuilding the datasets that already exist! Furthermore,
dataset records do not have to contain all fields defined
in the database. We call this "Sparse Field Technology".
Different records may carry different fields depending upon
application relevance. Very complex data structures may
be created.
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fields$
= "Primary,Name,Phone,Email"
samOpen%(txtDbFile.Text, READ_WRITE, DbHwmcb&,
LICENSE_KEY$, "")
rc% = VsamBOF%(DbHwmcb&, "Primary")
Do While rc% = VIS_OK
rc% = VsamGet%(DbHwmcb&,
"Primary", XNEXT, "", rskey$, rpkey$, hrec&)
If rc% = VIS_OK Then
buf$
= VsamReport$(DbHwmcb&, rpkey$, hrec&, fields$,
_
RPT_FMT_HRPTDATA,
"")
List1.AddItem
buf$
End If
Loop
VsamClose%(DbHwmcb&)
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All
fields have attributes one of which is Name. This
means that the fields in your dataset may be accessed
by Field Name or by Field Number. Some of the other
default attributes are Field Type, Indexed Flag, Justification,
and Width. Your software may add or modify field
attributes. Some of the default attributes such as
Field name may be changed as well.
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Great
data management software does more than just put records
into datasets. For information to be usefull, it must
be accessable in some context. It is the application
software that allows the context and VsamEx[treme]
supplies the flexability. Ad hoc query capabilities
are built in. Searching In VsamEx[treme] is simple.
It uses easy to understand "and", "or" and "not"
logic coupled with straight forward, English like,
constructs that may be used to build lists of
keys or other complete datasets (DynaSets)!
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Each
record is assigned a variable length key (Primary
key) that you supply and may be up to 252 characters
in length. Secondary indexes may be assigned from
any string field in the record, up to 250 characters
each, within the first 150 fields. There is no limit
to the number of records except that they must fit
inside the dataset (currently 2.1 GB max). The maximum
single record size is 65k bytes. All records and their
indexes are stored in the same file for easy maintenance.
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Extreme
it is!...
Extreme
Programming
is the method used to design and build the VsamEx[treme]
ISAM.
The Extreme nature of writing software this way results
in a more dynamic creative process that uses proven
Psychological, Engineering and other Scientific concepts
– where multiple developers, with different
talents and experiences, dynamically exchange ideas,
skills and code, in real-time – in order
to contribute to an outcome that is greater than the
sum of its parts!
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News