Real Time Information Director User Documentation

RTID Metadata Language
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2. Construct a QualifiedMapper, by calling the qualify method of the
UnqualifiedMapper object. The qualify method requires you to specify a value
for the typecode, so a search of the mapping table is restricted to the appropriate
rows.
3. Construct an actual mapping, within a document definition, by calling the map
method of the QualifiedMapper object. This call looks exactly the same as a call
to the map method of a Mapper object.
For more detailed information about Mapping enrichments, see “Mapping External to
Internal IDs,” later in this document.
Partitioning
Partitioning provides the ability to spread a table across multiple disks to help balance
workload and improve the performance of a solution. In partitioning, it is usually
beneficial to
• Distribute load evenly across disks and processors.
• Cluster related data on the same disk for efficient access.
• Concentrate most input/output for a transaction to a single partition.
Any table in your data store can have either a natural key (data present in the input
record, for example a customer name) or an artificial key (assigned by the Director itself).
The Director supports artificial partitioning for both kinds of tables: that is, the
Director can assign a partition ID, prepending it, as a separate column, to the logical key
of table. The strategy for assigning the partition ID depends partly on whether the key is
artificial or natural, as explained below. A partition ID assigned by the Director is
transparent to client applications, but the SQL administrator can use it as a basis for
partitioning the table.
The Director can also work with tables that have been naturally partitioned. In this
case, SQL partitions the table on the basis of the logical key. Natural partitioning is
transparent to the Director, which recognizes no distinction between a table that has been
naturally partitioned and an un-partitioned table.
Natural partitioning tends to be more beneficial than no partitioning at all, but not as
beneficial as artificial partitioning. The advantage of artificial partitioning is that the
Director can use your knowledge of how the data is typically accessed to help ensure that
the data is evenly distributed and efficiently clustered.
The Director can use any of the following partitioning strategies. You use metadata to
specify which strategy to use for each table.
• Round-robin partitioning. Each new record of a given type is assigned to the next
partition in a repeating sequence. This strategy ensures even distribution but does
nothing (by itself) to cluster the data. This strategy is especially suitable for