SQL Storage Compress - 6.0

Analyzing potential space savings - SQL Storage Compress

The SQL Storage Compress application includes features to help you review the space (on local SQL Server instances) currently used by your databases, and to estimate how much disk space you could save by compressing these databases.

Viewing current database sizes

To run the SQL Storage Compress application, select it from the Start menu (All Programs > Red Gate > SQL Storage Compress 6)
SQL Storage Compress automatically searches for local SQL Server instances when it runs. These instances are shown in the Database sizes tab:

In the example above, two instances (PRODUCTION and TEST) were detected.
To remove a local instance from the list, or change connection credentials, right-click the instance and select the appropriate command
To add an instance, click Add a local instance in the toolbar
Note: you can only browse for instances that are local (running on the same server as the SQL Storage Compress application). If there are no further instances on your machine, the button is unavailable.
Only user databases are listed. You can compress system databases if required, but these are usually too small to generate worthwhile space savings.
- Uncompressed databases are shown with a yellow icon and their Original (current) size. For a first-time installation of SQL Storage Compress, all databases will be shown as uncompressed.
- Compressed databases (where one or more database files are managed by SQL Storage Compress) are shown with a blue icon along with their Original (uncompressed) size, Savings (absolute and percentage figures), and Compressed size.
To list the details of each database file for a particular database, click the arrow to the left of the database icon; the logical database file names are shown.
Hover over a logical file name to see the full file path:
To open the folder containing a database file, right-click on the logical file name and select Locate file on disk.

Viewing potential space savings

Select the Summary of savings tab to see summary data for all instances shown on the Database sizes tab:

The data comprises:

Current savings: the number of compressed databases, and current space saved. For a first-time installation of SQL Storage Compress, both values will be zero.
Databases with multiple data files are considered to be compressed if at least one data file is compressed.
Potential savings: the number of uncompressed databases, and an estimate of the total space that could be saved if you compressed all these databases. This figure includes any savings resulting from databases that have already been compressed.
SQL Storage Compress calculates potential disk space savings by assuming each uncompressed database will be reduced by 80% when compressed.

The potential savings figure is an estimate, and assumes that all data files for a database will be compressed. The actual compression achieved will depend on the type of data in your database.
General information: the total number of databases, the number of encrypted databases, and the number of database files that could not be accessed.
Note that non-SQL Storage Compress encrypted databases are not counted in the 'Encrypted databases' figure.

Database files may be inaccessible to the SQL Storage Compress application if:
- your current login does not have permissions to read a database file on disk
- the instance is clustered, and the current node does not have access to the disk
When SQL Storage Compress cannot access a database file, it considers its size to be the same as the size reported to SQL Server; therefore, no savings are reported. It may be that the file is in fact compressed, but these savings cannot be shown.
Current vs potential size (graph)
Disk space shown on the graph is the total for all user databases running on the instances shown on the Database sizes tab:
- Original size: the total size for all database files, if no databases were compressed.
  If you haven't compressed any databases with SQL Storage Compress yet, this value represents the actual size on disk for all database files.
- Current size: the actual total size for all database files, including compressed database files.
  If you haven't compressed any databases with SQL Storage Compress yet, then this value is not shown.
  
  The difference between Original size and Current size is equal to Current space saved.
- Potential size: the estimated total size for all database files, if all databases were compressed.
  The difference between Original size and Potential size is equal to Total potential space savings (estimated).