15.40 SEM_APIS.CREATE_RDF_NETWORK
Format
SEM_APIS.CREATE_RDF_NETWORK( tablespace_name IN VARCHAR2, options IN VARCHAR2 DEFAULT NULL, network_owner IN VARCHAR2 DEFAULT NULL, network_name IN VARCHAR2 DEFAULT NULL);
Description
Creates structures for persistent storage of semantic data.
Parameters
- tablespace_name
-
Name of the tablespace to be used for tables created by this procedure. This tablespace will be the default for all the RDF graphs that you create, although you can override the default when you create a graph by specifying the
model_tablespace
parameter in the call to the SEM_APIS.CREATE_RDF_GRAPH procedure. - options
-
An optional quoted string with one or more of the following network creation options:
-
COMPRESS=CSCQH
uses COLUMN STORE COMPRESS FOR QUERY HIGH on the RDF_LINK$ and RDF_VALUE$ tables. -
COMPRESS=CSCQL
uses COLUMN STORE COMPRESS FOR QUERY LOW on the RDF_LINK$ and RDF_VALUE$ tables. -
COMPRESS=RSCA
uses ROW STORE COMPRESS ADVANCED on the RDF_LINK$ and RDF_VALUE$ tables. -
COMPRESS=RSCB
uses ROW STORE COMPRESS BASIC on the RDF_LINK$ and RDF_VALUE$ tables. This is the default compression level. -
MODEL_PARTITIONING=BY_HASH_P
uses list-hash composite partitioning to partition RDF_LINK$ by the graph ID and further subpartition each graph by a hash of the predicate ID. -
MODEL_PARTITIONS=n
sets the default number (n) of subpartitions to use for each RDF graph. This option is used in conjunction withMODEL_PARTITIONING=BY_HASH_P
. -
MODEL_PARTITIONING=BY_LIST_G
uses list-list composite partitioning to partition RDF_LINK$ by RDF graphID
and further subpartition each model by graphID
. This subpartition is automatically maintained as data is inserted into the graph. -
NETWORK_MAX_STRING_SIZE=EXTENDED
specifies a maximum VARCHAR size of 32767 bytes for storing RDF values. Values larger than 32767 bytes will be stored as CLOBs. -
NETWORK_MAX_STRING_SIZE=STANDARD
specifies a maximum VARCHAR size of 4000 bytes for storing RDF values. Values larger than 4000 bytes will be stored as CLOBs. This is the default. -
NETWORK_STORAGE_FORM=ESC
specifies use of escaped storage form for lexical values in RDF_VALUE$. Unicode characters and special characters will be stored using ASCII escape sequences. (You cannot specify both the escaped and unescaped storage forms.) -
NETWORK_STORAGE_FORM=UNESC
specifies use of unescaped storage form for lexical values in RDF_VALUE$. Unicode characters and special characters will be stored as single characters. This is the default.
-
- network_owner
-
Owner of the RDF network. (See Table 1-2.)
- network_name
-
Name of the RDF network. (See Table 1-2.)
Usage Notes
This procedure creates system tables and other database objects used for semantic technology support.
You should create a tablespace for the semantic technology system tables and specify the tablespace name in the call to this procedure. (You should not specify the SYSTEM
tablespace.) The size needed for the tablespace that you create will depend on the amount of semantic technology data you plan to store.
You must connect to the database as a user with DBA privileges or as the intended network owner in order to call this procedure, and you should call the procedure only once for the database.
To drop these structures for persistent storage of semantic data, you must connect as a user with DBA privileges or as the owner of the schema-private network, and call the SEM_APIS.DROP_RDF_NETWORK procedure.
The options COMPRESS=CSCQH
, COMPRESS=CSCQL
, and COMPRESS=RSCA
should be used only if you have the appropriate licenses.
After the RDF network is created, a row in the RDF_PARAMETER table with NAMESPACE = 'NETWORK' and ATTRIBUTE = 'COMPRESSION' will indicate the type of compression used for the RDF network.
NETWORK_MAX_STRING_SIZE=EXTENDED
can only be used if your database has
extended VARCHAR support enabled (see Extended Data Types).
For information about RDF network types and options, see RDF Networks.
Examples
The following example creates a tablespace for semantic technology system tables and creates structures for persistent storage of semantic data in this tablespace. Advanced compression is used for the RDF network.
CREATE TABLESPACE rdf_tblspace DATAFILE '/oradata/orcl/rdf_tblspace.dat' SIZE 1024M REUSE AUTOEXTEND ON NEXT 256M MAXSIZE UNLIMITED SEGMENT SPACE MANAGEMENT AUTO; . . . EXECUTE SEM_APIS.CREATE_RDF_NETWORK('rdf_tblspace', options=>'MODEL_PARTITIONING=BY_HASH_P MODEL_PARTITIONS=16');
Parent topic: SEM_APIS Package Subprograms