SQL/MX 2.x Installation and Management Guide (G06.24+, H06.03+)

Reorganizing SQL/MX Tables and Maintaining Data
HP NonStop SQL/MX Installation and Management Guide—523723-004
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Using import to Load Partitions
6. Run POPULATE INDEX to load the data into the indexes.
For information about CREATE INDEX and the NO POPULATE option, see the
SQL/MX Reference Manual.
Managing Triggers to Improve import Performance
Triggers degrade import performance by causing triggered actions to be performed
during the operation. Before you perform an import operation on a table with triggers,
use the import -D option to disable all triggers. After the data has been inserted,
import automatically enables the disabled triggers.
Managing Data Types to Improve import Performance
import requires additional processing for all date time (DATE, TIME, and
TIMESTAMP), numeric, and decimal data types. import reads the format file, extracts
the value of the input file, and converts it to a form recognized by NonStop SQL/MX.
For numeric and decimal data types, import converts the value to the scale and
precision required by NonStop SQL/MX.
Using import to Load Partitions
•
For range partitioned tables, use the import command to specify the key-range
values that identify the range that you want to load. You cannot specify individual
partitions for loading.
•
For hash partitioned tables, import loads all hash partitions in the destination
table in a single operation.
Using import to Perform Serial Partition Loads
import runs one instance of the import operation to perform a serial load on partitions
in an SQL/MX table.
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 processor
time during import such that:
•
Parallel load provides benefits.
•
Sorting 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: