Name
DB.DBA.RDF_BACKUP_METADATA — Makes a backup copy of RDF metadata (i.e., descriptions of Linked Data Views and the like).
Synopsis
DB.DBA.RDF_BACKUP_METADATA ( |
in save_to_file integer := 0 , |
in backup_name varchar := null
); |
Description
This saves all RDF metadata to file or to some graph in RDF storage, depending on first argument (nonzero for file, zero for graph). If the function gets nonzero as first argument then it creates two files, called, say, 'example.ttl', and 'example-DEBUG.ttl'. It's enough to save only the former file in order to restore metadata later, but the latter contains important additional debug information so both files should be attached to any bug report related to RDF metadata.
There are no functions to make copies of backups. File backup consists of plain TURTLE RDF files only. Backup graph is just a regular RDF graph in the default storage so it can be serialized into a file or copied into other graph. However it is important to remember that the system graph, whose name is returned by JSO_SYS_GRAPH() stored procedure, should not be edited directly. The content of the system graph is not necessarily equal to the content of a backup graph and it should be touched only by API function calls.
Parameters
save_to_file
Value of 1 to backup to a files, 0 to backup into graph.
backup_name
Name of destination graph or file. Graph should be empty before backup, but file with the specified name may exist before backup and will be silently overwritten. When the destination is file, the '.ttl' extension is concatenated to the backup_name. If the argument is null then the backup name will contain date and time of backup creation, like '2007-12-31T23:59.59'.
Return Types
The function returns the actual name of the created backup as a string.