Displaying Free Space Information

To get free space information, you can display the Database Freespace page of the Management Portal or use the ^%FREECNT utility.

Remember that the size and free space attributes of a database in normal operation change continuously, and that numbers reported by the portal or the utility at a given point in time are approximations only.

Display Free Space Information Using the Management Portal

To display the Database Freespace page, which shows information about the amount of free space on each local database and lets you compact and/or truncate databases, navigate to the Databases page and click Freespace. The following table describes the information displayed on the Database Freespace page:

Local Databases Freespace Information

Column Heading	Definition
Name	The database name.
Directory	The system directory in which the primary volume of the database resides.
Max Size	The maximum allocated size to which the database can grow, in gigabytes. The default is unlimited when you create a database.
Size	The current allocated size of the database, in megabytes.
Expansion Size	Size (in MB) by which to expand the database. The default and recommended setting is zero (0) when you create a database, which indicates the use of system defaults (12% of the current size or 10 MB, whichever is larger). Under this setting, the expansion size will not be greater than 1GB.
Available	The amount of free space (in MB) available in the database.
% Free	The percentage of free space available in the database.
Disk Free Space	The amount of space free on the volume.
Status	The status of the directory, which indicates if the database is mounted and with what permissions.

Managing the free space (empty blocks) in a database is an important aspect of database maintenance. You can perform the following free space management operations on the Database Freespace page

Compact a database — Move free space distributed throughout a database to its end
Truncate a database — Return free space at the end of a database to the underlying file system

In addition, you can use the ^DATABASE utility for the following database management operations involving global blocks (blocks containing global data):

Compact globals in a database — Reduce unused space within global blocks and the overall number of global blocks, increasing free space
Defragment globals in a database — Relocate global blocks so that the blocks representing a given global are in continuous sequence

The ^DATABASE utility can also be used to display free space information and to compact and truncate databases, along with performing other database tasks such as recreating a database, which lets you clear the data in an existing database without changing the database’s name or size. See ^DATABASE in the “Using Character-based Security Management Routines” chapter of the Caché Security Administration Guide for information about the utility.

Note:

The data structures used by Caché are self-balancing and suffer no performance degradation over time. It is never necessary to take a database down to rebuild it nor to compress data or indices to regain performance.

Display Free Space Information Using ^%FREECNT

Caché also provides the ^%FREECNT utility, which you run by entering do ^%FREECNT in the Terminal, to display the free space available in a database.

When using ^%FREECNT in the %SYS namespace, you can choose to display the free space of all databases by entering an asterisk (*) at the prompt, or enter one database directory name. For example:

%SYS>do ^%FREECNT
 
Database directory to show free space for (*=All)? *
 
Databases Selected
------------------
c:\MyCache\mgr\
c:\MyCache\mgr\cacheaudit\
c:\MyCache\mgr\cachelib\
c:\MyCache\mgr\cache\
c:\MyCache\mgr\cachetemp\
c:\MyCache\mgr\docbook\
c:\MyCache\mgr\samples\
c:\MyCache\mgr\user\
Device:
Right margin: 80 =>
 
 
                           Cache Database Free Space
                              Feb 15 2012  7:25 PM
Database                           Max Size  Size    Available %Free   Disk Free
c:\MyCache\mgr\                    Unlimited 191MB   19MB      9.94    60.79GB
c:\MyCache\mgr\cacheaudit\         Unlimited 1MB     0.43MB    43      60.79GB
c:\MyCache\mgr\cachelib\           Unlimited 319MB   27MB      8.46    60.79GB
c:\MyCache\mgr\cache\              Unlimited 1MB     0.55MB    55      60.79GB
c:\MyCache\mgr\cachetemp\          Unlimited 4MB     1.5MB     37.5    60.79GB
c:\MyCache\mgr\docbook\            Unlimited 144MB   11MB      7.63    60.79GB
c:\MyCache\mgr\samples\            Unlimited 114MB   52MB      45.61   60.79GB
c:\MyCache\mgr\user\               Unlimited 1MB     0.43MB    43      60.79GB

In a namespace other than %SYS, the utility shows the free space of the databases in that namespace. For example:

USER>Do ^%FREECNT
 
 
Databases Selected
------------------
c:\MyCache\mgr\user\
Device:
Right margin: 80 =>
 
 
                           Cache Database Free Space
                              Feb 15 2012  7:28 PM
Database                           Max Size  Size    Available %Free   Disk Free
c:\MyCache\mgr\user\               Unlimited 1MB     0.52MB    52      42.72GB

Note:

A <- flag (in the %Free column) indicates that the percentage of free space in the specified database has dropped below 5%. Ensure that there is enough space on the filesystem to handle database expansion.

You may choose the device to which to send the information and choose the line length of the display.