HP Neoview Release 2.5 Software - Manual (Page 22)

in the “Maps” (page 41) section of the control file to perform a reflexive update. See “Control
File: Reflexive Update” (page 101) .
Reflexive Update Considerations
• Reflexive updates apply only to columns with numerical values.
• The input value provided for a reflexive update must match the range of values that are
legal for the target column.
• You cannot use reflexive update on primary key columns.
• The update map entry option defaults to true for all non-primary key columns.
Updates Using Constant, NULL, or Expression
In addition to reflexive updates, Transporter provides for updating Neoview SQL columns with
a constant, a NULL, or an expression. Use the source and target field mappings in the
“Maps”
(page 41) section of the control file to update columns with these values. Refer to this control
file example for details: “Control File: Update with Constant, NULL, or Expression ” (page 102) .
Identity Columns
In Neoview SQL, you can use IDENTITY columns to automatically generate values that are
unique across all partitions of the table for that column. IDENTITY columns can be used as
surrogate keys and to uniquely identify records with the same key. For more information, refer
to the HP Neoview SQL Reference Manual.
Transporter supports the creation of an IDENTITY column in target tables, and automatically
generates values for the identity column as part of the load task. The resulting column can be a
surrogate key in the table. Use the source and target field mappings in the
“Maps” (page 41)
section of the control file to have Transporter generate data for identity columns. See Example A-11
(page 104) .
NOTE: The maximum value for the identity value is the same as a Java long data type
(java.lang.Long.MAX_VALUE) when the target column is a LARGEINT data type. That is,
9223372036854775807.
Data Compression
As of Release 2.4 SP2. Transporter offers a data compression feature using a run-length encoding
(RLE) algorithm to compress data that is compressible, such as varchars, during staging table
and nonaudited loads.
This means that if a column is defined as VARCHAR(200), but the data is only 20 characters, the
data will no longer be padded to expand to the 200–character definition if compression is enabled.
Compression is enabled by default and applies only to loads in which one of these control file
options is set to true: forcestaging, noaudit, or inlinesort.
To disable compression for a particular load job, use the “compression” (page 53) control file
option:
compression = false
Multi-session Side-tree Inserts
Neoview SQL supports multi-session side-tree inserts as of Release 2.4 SP2; therefore, Transporter
no longer ignores the teamsize option during staging table and nonaudited loads. When used
with the parallelstreams option, the teamsize option doubles or quadruples the possible
number of connections that process data during a staging table or nonaudited load.
22 Functions and Features