(B)0[mmap-storage-clause =
[4mSTORE[m qw> map-within-clause qqqqqqqqqqqqqqqqqqqqqqqqqqwqk
m> [4mUSING[m qw> field-name qw> map-within-clause qj x
mqqqqq , <qqqqqj x
lqqqqqqqqqqqqqqqqqqqqqqqq<qqqqqqqqqqqqqqqqqqqqqqqqqqqqqj
mqwqqqqqqqqqqqqq>qqqqqqqqqqqqqqwqq>
m> default-threshold-clause qj
Used to define a storage map. This clause lets you specify which
storage area files will be used to store rows from the relation:
o All rows of a relation can be associated with a single storage
area.
o Rows of a relation can be randomly distributed among several
storage areas.
o Rows of a relation can be systematically distributed, or
partitioned, among several storage areas by specifying upper
limits on the values for a column in a particular storage
area. This is called horizontal partitioning.
If you omit the storage map definition, the default is to store
all the rows for a relation in the main RDB$SYSTEM storage area.
Additional Information:
explode
extract