A pattern table contains patterns against which a file's name and creating process' UID and GID are matched as a file is created in a directory. If the directory does not have its own pattern table or an inheritable allocation policy, the file system's pattern table takes effect. The first successful match is used to set the allocation policies of the file.
The following example shows how to assign pattern tables to a file system in a volume set that contains two volumes from different classes of storage. The pattern table is contained within the pattern file