SQL/MX 3.1 Installation and Management Guide (H06.23+, J06.12+)

Reorganizing SQL/MX Tables and Maintaining Data
HP NonStop SQL/MX Release 3.1 Installation and Management Guide—663852-001
10-31
Using import to Load Partitions
can also specify the start and end positions of the range partition based on the key
column data in the input file. However, you cannot use these options to specify an
actual key value at the command line.

For hash-partitioned tables, import loads all hash partitions in the destination
table in a single operation.
Using import to Perform Serial Partition Loads
To perform a serial load on the partitions of an SQL/MX table, use one instance of
import with the data in the input file sorted first by partition number and, for
performance reasons, sorted secondarily by the clustering key.
Using import to Perform Parallel Partition Loads
Use multiple instances of import to perform a parallel load when the destination table
is range-partitioned and it has no indexes. Some data types require more CPU time
during
import such that:

Parallel load provides benefits.

Presorting data by storage key results in faster import time.

Using more processors improves parallel load performance.
You cannot import files into one partition in parallel (that is, you cannot have two
instances of
import loading the same partition). Otherwise, NonStop SQL/MX returns
a locking error.
There are two ways to perform a parallel load:

Run multiple instances of the import command—one for each partition in the
destination table—to load data into a partitioned table by using a single input file.
For each
import command, specify the number of input rows (records), the
number of the first record to import, and the transaction size.
For example, suppose that you partition the EMPLOYEE table into three partitions.
The first partition begins with 0 (zero) for the employee number, the second
partition begins with 3000 for the employee number, and the third partition begins
with 5000 for the employee number.
You might specify the three
import commands as follows:
/usr/bin:import corpcat.persnl.employee -I empfile -C 3000 -T 500
/usr/bin:import corpcat.persnl.employee -I empfile -C 2000 -F 3000 -T 500
/usr/bin:import corpcat.persnl.employee -I empfile -C 2000 -F 5000 -T 500
The count of the number of records for each partition must be less than or equal to
the space available in each partition, and the rows to be imported into each
partition must have an appropriate clustering key. In the preceding example, the
first partition permits employee numbers ranging from 0 to 2999.
Note. Check that the ranges specified are exact. For example, check that there are no
gaps or omissions and no overlap of rows.