BLOCKSIZE= Table Option
Specifies the size of a SASHDAT file block in bytes,
kilobytes, megabytes, or gigabytes.
| Category: |
Table Control |
| Default: |
2M, or the length of the record, whichever is greater |
| Data source: |
SASHDAT file |
Syntax
BLOCKSIZE=n[B] | nK | nM | nG
Arguments
n[B]
specifies the block
size to use in bytes. This is the default value when you do not specify
a multiplier. If used, the B must be uppercase.
nK
specifies the block
size to use in kilobytes. K is a multiplier and must be specified
as uppercase.
nM
specifies the block
size to use in megabytes. M is a multiplier and must be specified
as uppercase.
nG
specifies the block
size to use in gigabytes. G is a multiplier and must be specified
as uppercase.
Details
You do not have to specify
a block size when partitioning data into HDFS. If you do specify a
block size, it is considered an upper bound for the partition request.
The actual block size
is slightly larger than the value that you specify. This occurs for
any of the following reasons:
-
to reach the record length.
-
to include a metadata header in
HDFS for the SASHDAT file.
-
to align on a 512-byte boundary.
Example
create table hdat.schema1.rent{OPTIONS blocksize=10000}
create table hdat.schema1.rent{OPTIONS blocksize=1000 K}
create table hdat.schema1.rent{OPTIONS blocksize=1G}