Databases Reference
In-Depth Information
Oracle relational sources. Gateways can optionally provide a higher level of per‐
formance when extracting data from non-Oracle sources.
Transportable Tablespaces
Another feature for data movement, Transportable Tablespaces enable rapid data
movement between Oracle instances without export/import. Metadata (the data
dictionary) is exported from the source and imported to the target. The transferred
tablespace can then be mounted on the target. Oracle Database 10
g
introduced
cross-platform Transportable Tablespaces, which can move a tablespace from one
type of system (e.g., Solaris) to another (e.g., Linux).
Transportable Partitions
Oracle Database 11
g
introduced Transportable Partitions for rapid data movement
between Oracle instances.
Data Pump Fast Import/Export
Added in Oracle Database 10
g
and enabled via external table support, Data Pump
is a newer import/export format. Parallel direct path loading and unloading are
supported.
Oracle Big Data Connectors
First available in 2011, Oracle's Big Data Connectors include an Oracle Loader for
Hadoop that pushes the preprocessing of data to be loaded into an Oracle data
warehouse to the source Hadoop Big Data cluster. The result is lessened CPU and
I/O impact on the target Oracle Database platform. An Oracle Data Integrator Ap‐
plication Adapter for Hadoop provides ODI Knowledge Modules optimized for
Hive and the Oracle Loader for Hadoop. An Oracle Direct Connector for HDFS
and an Oracle R Connector for Hadoop are also provided.
The Oracle Database helps the ETL and loading process in a variety of ways. For high-
speed loading of flat files, Oracle SQL*Loader's
direct path load
option provides rapid
loading by bypassing the buffer cache and rollback mechanism and writing directly to
the datafile. You can run SQL*Loader sessions in parallel to further speed the table-
loading process (as many warehouses need to be loaded in a limited “window” of time).
Many popular ETL tools, including ODI, generate SQL*Loader scripts.
The core Oracle Database engine features embedded ETL functions that ETL tools sup‐
port to varying degrees. Examples of these features include support for external tables,
table functions, merge (i.e., insert or update depending on whether a data item exists),
multitable inserts, change data capture, and resumable statements.
Managing the Data Warehouse
Oracle Enterprise Manager (EM) provides a common GUI for managing your multiple
database instances regardless of the underlying operating system and server platform
