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ShareWare OnLine 2
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ShareWare OnLine Volume 2 (CMS Software)(1993).iso
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a4backup.zip
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BACKUP.TXT
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1993-01-27
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Backing up Alpha FOUR files
Once you start acquiring a substantial amount of data in your
databases or you have taken the time to design a set or
application that works well for you, you don't want to take
chances with all your work. Backing up your data is essential.
Although full hard drive crashes are relatively uncommon, they do
happen. More likely is the possibility of loosing one or a few
files due to a variety of causes and it is just a matter of time
before you loose at least one important file associated with your
databases. Having a recent backup will save you much frustration
and hours and possibly days of work recreating the data if this
is even possible.
This document will cover what you need to know about Alpha FOUR
files to keep your data backed up. The software you use to
perform the backup is up to you. There are many very good backup
programs on the market and you can check with your local software
dealer for their recommendation.
Where are the data files stored?
Although you may store your database files anywhere you wish, we
recommend that you use a directory under the \ALPHA4V2\ directory
(called \ALPHA4\ in version 1) to store your data files. You can
store your data files in the \ALPHA4V2\ directory along with the
program files, however it is much easier to backup and copy the
data files if they have been stored in a separate directory.
C:\> (root directory)
\ALPHA4V2\ (directory containing program files,
called \ALPHA4\ in version 1)
\ALPHA4V2\DATA\ (directory containing database files)
\ALPHA4V2\JOAN\ (directory containing Joan's database files)
A good way to find out where your data is stored is to open that
database within Alpha FOUR by selecting (from the main menu)
Choose, Open. If you had your database loaded when you did this,
Alpha FOUR will show you the directory of files located in the
current data directory which should include the database you were
in. Note the Drive/Path information at the top of this screen.
This displays the name of the directory that contains all the
files shown on the screen.
See the reference manual under "Open a database" for more
information on navigating this directory screen. If all your data
files are not shown on this directory (use the arrow keys to
scroll up and down), it could be that other important data files
have been stored in another directory.
Which Files to back up
The following list contains the files that you are most likely to
want to keep backed up. Don't let the plethora of file extensions
get you down. Notice that the majority of files associated with a
database share the same filename. This way you can just specify
to copy/backup all files with that name regardless of the
extension (filename.*). In this chart filename refers to the name
of the database or set.
File Notes Ver 1 Ver 2
Data file. Contains all the records filename. filename.
from your database dbf dbf
Memo fields. Contains the contents of filename. filename.
any memo type fields. If dbt dbt
you have no memo fields in
a given database it will
not have a .DBT file.
Index files. Note that the index files indexname indexname
associated with a database .ndx .ndx
do not share the database
name. Index files can take
up a lot of space and are
usually easily recreated.
You may want to ignore the
index files when backing up
unless you are backing up a
set.
Form Layout. Contains the screen layout filename. filename.
you see when you choose V I4x INx
for View. Note this is not
your actual data but
controls the way the data
is shown.
Browse Table Contains the screen layout filename. filename.
Layout. you see when you choose B B4x BNx
for Browse. Note this is
not your actual data but
controls the way the data
is shown.
Mail Label filename. filename.
Layout. L4x LNx
Report filename. filename.
Layout. R4x RNx
Letter Note that the letter files letternam letternam
files. are not associated with a e.LTR e.LTR
specific database and
therefore do not
necessarily share a name
with any database.
Field Rules. filename. filename.
RL4 RLN
Range filename. filename.
Definition. G4x GNx
Saved Search filename. filename.
Criteria S4x SNx
Saved Global (version 1.1 and above) filename. filename.
Update U4x UNx
Criteria.
Set file. This is the set design setname.S setname.S
only. Databases and indexes ET ET
associated with the set are
stored in their own
separate files.
Application Application and macros. Any appname.A appname.A
file. scripts played through an P4 PP
application are saved in
their own separate file.
Application If your application uses a appname.A appname.A
Banner custom banner make sure to S4 S4
Screen. include this file in any
backup.
Script files Each script is stored in a N/A scriptnam
separate file. If your e.SCP
script(s) refer to other
scripts, make sure to also
backup the called script.
This list is by no means all inclusive. It represents only those
files that are the most closely tied to the data and would take
you the longest to recreate should you loose the original files.
For a more comprehensive list of all the data files used in Alpha
FOUR, consult the reference manual.
Three backup options
If you would like to backup your Alpha FOUR files the first thing
to decide is how complete you want your backup to be. The Quickie
backup described below will take less time and disk space but
will only backup the essential data files. A full data backup
will take more time and disk space but will give you a full
backup of all data files and related files which may be more
useful should you loose the original.
Quickie backup (just the data files)
If you are concerned only about keeping an extra copy of your
data, consider only backing up the filename.DBF and filename.DBT
files. You will not have a backup of your layouts, field rules
etc, however, if the database becomes corrupted you still have an
extra copy of the data. This represents the most time/space
efficient backup.
Mid-Level database backup (including layouts and other associated
files)
If you also want to also back up the database's layouts (forms,
browse tables, reports, mail labels), field rules, range
settings, saved search criteria, and saved global update
criteria, you can backup/copy all files that share the filename
with that database. Most backup programs accept the DOS wild card
filename.* and this will back up these files as well as the data
files covered by the quick backup. This will not backup the index
files or the letters.
Full data backup (all files associated with a database or set)
For a full backup of all files associated with a database you can
either backup the entire directory containing the database(s).
This would also backup all other databases in this directory. If
you want to specify which files to backup, you can backup the
following files:
filename.* all files sharing the database name
indexname.NDX do this for all indexes associated with that
database
lettername.LTR do this for all letters used with that
database
setname.* all files sharing the set's name (if you are
backing up a set).
Note on Sets:
When copying or backing up a set it is important to copy all
pertinent files from all databases associated with the set.
Remember to backup/copy the indexes you use to link the databases
together. Sets can also have their own field rules, forms etc so
it is a good idea when backing up or copying a set to copy all
files that share the set name (setname.*). Also remember to copy
all of the set files to the same directory. A set cannot refer to
files in another directory.
Note on applications:
When copying or backing up an application it is important to
backup/copy all pertinent data from all databases associated with
the application. If the application does not change, for
subsequent backups you can simply copy the database(s) without
needing to re-copy the application file. It is also important to
copy any script files (.SCP) or banner screens (.AS4) that are
used in the application.
Note on scripts:
Script files all have an .SCP extension. Backing up or copying
script files is simply a matter of copying all SCP files (*.SCP)
in the script path directory. If a script refers to another
script remember to also copy that script file.
Questions
Q How often should I backup my files?
A Often, but "often" can be interpreted differently depending
on how much you would be willing to loose if the files became
corrupted. Data problems can happen anytime and it is a good idea
to implement a backup schedule that is based on how much data
entry/changes you do in a given time period. Ask yourself this
question "If my hard drive crashed today and I lost all the data
on it, when did I do my last backup and was the data I lost
(since the last backup) worth the time I saved by not backing up
more frequently?" Based on your situation, determine how much
data you would be willing to loose (1 day, 1 week, 1 month). and
weigh this against the time it takes to backup. In most cases you
can automate the backup process and make it quicker so you will
be willing to do it more frequently.
Note: If your database has become corrupted, Alpha Software has a
document specifically on database corruption that is available by
contacting the tech support department.
Q What's the difference between backing up files and copying
them to another place?
A Usually a "backup" is a compressed version of the original
file. By compressing the file, the backup software allows you to
store more information on the backup medium (usually a floppy
diskette) than if the files were simply copied. The backup
program can also handle splitting larger files between two or
more disks which is usually not possible with a simple copy.
Q When I lost my data due to a hard drive crash, I copied the
backup files onto my hard drive but Alpha FOUR would not
recognize them. Why?
A If you did indeed backup your files, no-doubt the backup
program compressed the files and you need to restore the backed
up files to the hard drive rather than simply copying them.
Properly restoring the backed up files uncompressed the files
into their original usable format on the hard drive.
Notes on preventing data corruption
The best way to prevent loss of data is to avoid data corruption
in the first place. Here are some suggestions to help you avoid
potential problems.
Check your disk for viruses regularly. There are some good
virus detection programs available for doing this. Make sure
that you always have the latest version of the software
because new computer viruses crop up regularly and the
software is constantly being updated to recognize the new
viruses in circulation.
In the Alpha FOUR default settings, set "auto flush" to yes.
Setting this to yes ensures that no more than the last record
is potentially lost should your computer crash during data
entry or experience memory problems. With Auto flush set to
yes, Alpha FOUR copies each record down to the hard drive when
you press F10 to save the new entry. Without this, Alpha FOUR
collects new records in memory and only "flushes" them to disk
when the memory gets full. To get to the default settings,
from the main menu choose Other, Configuration, Default
settings.
We recommend that you make a backup or copy of the database
before performing the following operations. These operations
do not corrupt files but they permanently change the data and
therefore posses the greatest potential for data loss if the
user does not know how to properly implement them. It is
always a good idea to have a backup just in case you misjudged
the result.
Global Update (unless you are updating a brand new field)
Reconfigure
Re-evaluate field rules
Pack
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