derby.storage.useDefaultFilePermissions

Function

If you run with Java SE 7 or later, and if you start the Derby Network Server from the command line, access to databases and to other files created by Derby is by default restricted to the operating system account that started the Network Server. File access is not restricted for embedded databases or for databases managed by servers that are started programmatically inside application code using the Derby API.

You can override this default behavior by setting the system property derby.storage.useDefaultFilePermissions to either true or false:

If you use a version of Java SE earlier than Java SE 7, this property is ignored, and Derby uses the default file permissions the user has set for their system.

The two tables that follow show how file access works with Java SE 6 and with Java SE 7 and later JVMs. In both tables,

"Environment" means that access is controlled entirely by the JVM environment and the file location only (that is, by the umask setting on UNIX and Linux systems and by the default file permissions on Windows NTFS).
"Restricted" means that Derby restricts access to the operating system account that started the JVM.

The following table shows how file access works on Java SE 6 systems.

Table 1. File access on Java SE 6 systems
Property Setting	Server Started from Command Line	Server Started Programmatically or Embedded
Not applicable	Environment	Environment

The following table shows how file access works on Java SE 7 and later systems with various settings of the derby.storage.useDefaultFilePermissions property.

Table 2. File access on Java SE 7 and later systems
Property Setting	Server Started from Command Line	Server Started Programmatically or Embedded
No property specified	Restricted	Environment
Property set to true	Environment	Environment
Property set to false	Restricted	Restricted

For more information, see "Controlling database file access" in the Derby Server and Administration Guide.

Default

By default, this property is not set.

Example

derby.storage.useDefaultFilePermissions=true

Scope

system-wide

Dynamic or static

Dynamic. Existing files will keep their previous permissions, but files created after the property is set will have the permissions specified by the property. If you want all the files in the database to have the same permissions, do not change the property while Derby is running.

For information about dynamic changes to properties, see Dynamic and static properties.