DAS

Description

DAS marks database segments as "deleted", making the segment storage space available to other programs. Deleted segments cannot be recovered.

Parameters

Name	Type	Caption	Length	Value range
FILE *	String	Input file name	1 - 192
DBSL *	Integer	Segment(s) to delete	1 -
REPORT	String	Report mode	0 - 192	Quick links
MONITOR	String	Monitor mode	0 - 3	ON, OFF Default: ON

* Required parameter

Parameter descriptions

FILE

Specifies the name of the PCIDSK file containing segments to be deleted.

DBSL

Specifies the segments to delete.

Ranges of channels or segments can be specified with negative values. For example, {1,-4,10} is internally expanded to {1,2,3,4,10}. When you are not specifying a range in this way, only 48 numbers can be specified explicitly.

REPORT

Specifies where to direct the generated report.

Available options are:

• TERM: generates a report on the terminal (default)
• DISK: generates a report on file "IMPRPT.LST"
• OFF: turns off report generation
• <filename>: appends a report to the specified file

MONITOR

The program progress can be monitored by printing the percentage of processing completed. A system parameter, MONITOR, controls this activity.

Available options are:

• ON: Turns the monitor ON (default)
• OFF: Turns the monitor OFF (recommended if running in batch or background mode)

Details

DAS deletes a specified set of database segments (DBSL) from a PCIDSK file (FILE). The space used by the deleted segments is made available for new segments. DAS does not physically delete the segment or the data stored on it; it simply marks the segment as "deleted". This makes the segment inaccessible to the user, but allows other tasks to create new segments that overwrite the deleted segment.

To permanently delete a segment, run PCIMOD with PCIOP set to "COM" to compress the space.

Locked segments (especially the georeferencing segment, which is usually the first segment on the file) cannot be deleted.

Deleted segments cannot be recovered.

Example

Delete a large vector segment, and immediately recover the disk space.

EASI>FILE="irvine.pix"
EASI>DBSL=25
EASI>RUN DAS

EASI>PCIOP="COM"               ! Compress deleted segments
EASI>RUN PCIMOD