IBM 000-8697 Manual Do Utilizador

Utilities

The next command imports the stores5 database from tape into the auckland
dbspace. The database is created with unbuffered logging. The command
suppresses the echo of the SQL statements and continues processing unless
fatal errors occur.

dbimport -cq -d auckland -l -t /dev/rmt0 -b 16 -s 24000 stores5

The dbload utility transfers data from one or more

ASCII

 files into one or

more existing tables. The dbload utility offers four advantages over the

LOAD

 statement:

■

You can create the data that dbload will load, unrestricted by the
format or the arrangement of data in an existing input file. The
dbload

command file can accommodate data from entirely different

database management systems.

■

You can specify a starting point in the load by directing dbload to
read but ignore x number of rows.

■

You can specify a batch size so that after every x number of rows are
inserted, the insert is committed.

■

You can limit the number of bad rows read, beyond which dbload
ends.

The cost of dbload flexibility is time and effort spent creating the dbload
command file, which is required for dbload operation. The

ASCII

input files

are not specified as part of the dbload command line. Neither are the tables
into which the data is inserted. This information is contained within the
command file.

The presence of indexes greatly affects the speed with which the dbload
utility loads data. For best performance, drop any indexes on the tables
receiving the data before you run dbload. You can create new indexes after
dbload

 has finished.