Help For Compress
Though the information shown here refers to DirectTalk/2,
it is applicable to the Windows NT version as well.
COMPRESS is a DirectTalk/2 user requester that will compress
any DirectTalk/2 database. When DirectTalk/2 deletes data from a database, the
data is not physically removed from the file until the database is compressed.
This program mimics the function provided by the Compress
feature in the Voice Application Developer. Compressing a database will remove
this previously deleted information and reduce the file size. This program will
back up a database file before starting compression. You may specify wild cards
to have the program compress more that one database with a single invocation of
the program. There are two methods available to compress a database:
- sequential read/write - This is the same method used by the
Compress feature in the Voice Application Developer.
Each record is read from the original database and written to the new
database in ASCII search order based on the record key ie. 0001, 0002, 0003,
- optimum read/write - This method was recommended by Paul
Herman and Joe Fanelli, two of the original DirectTalk/2 developers. This
method provides for optimum balancing of the binary tree used to search the
database when it is read. With this method, all of the keys are read into
memory. Each record is read and written starting with the median key and
working out to the first (lowest) and last (highest) key, alternating back
and forth For example, for a database with 5 records keyed sequentially 1 to
5, the records will be written in the following order: 3, 2, 4, 1, 5. (Using
the sequential method, they would be written as follows: 1, 2, 3, 4, 5.) The
optimum method is the default method used by COMPRESS.
COMPRESS is executed with the following command format:
COMPRESS <options> filemask
where the items in < > are optional.
|<server> is the name of the DirectTalk/2 GSI node and
is optional. If not specified, the program will assume
the node name is GSSSN01.|
|filemask is the mask used to determine which databases to
compress. You mayuse the search characters, '?' and '*', in the mask. To
compress all database files on your system, execute COMPRESS *.*
<server>. Do not specify any path as part of the filemask. The program
will locate the actual path for all DirectTalk/2 databases as needed.|
|options> are optional. The following options are
- Before compression is started, each database is
backed up to $$COMPSS.$$$. This file cannot exist before starting COMPRESS.
As each database is successfully compressed, the backup file is deleted. If
all databases are compressed without error, it is deleted as the program
completes execution. The name of the temporary work file can be changed, if
desired. See the /T option above.
- The program will produce informational messages showing you
the amount of space reclaimed as a result of the compression and the number
of files processed actually processed by COMPRESS.
- COMPRESS will display an informational message and continue
processing if any of the files found matching the mask are not DirectTalk/2
database files or the files are read-only.
- DirectTalk/2 must be installed and running for COMPRESS to
- The program will fail if another DirectTalk/2 process or
application has one or more records locked in any
- You must install and run COMPRESS on the DirectTalk/2
system where the databases are physically located. Otherwise, COMPRESS will
fail as it will not be able to back up the database(s).
- COMPRESS must be kept and run from the DTALK directory. If
you intend to use the /H (display help) option, COMPRESS.HLP must be kept
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