NonStop SQL/MP Reference Manual

NonStop SQL/MP Reference Manual—142115
A-38
Considerations—ALTER TABLE
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A one-way split moves the first or last part of a partition to a new partition,
leaving the remaining part in the existing partition:
MOVE FROM KEY val TO dest-part [WITH SHARED ACCESS]
MOVE UP TO KEY val TO dest-part WITH SHARED ACCESS
In a one-way split, name specifies the table for the operation. The partition that
is split is the one whose data range includes the key val, even if the specified
partition does not actually contain a row with that key.
The combination of node name and volume name for a new partition (whether
specified explicitly or by default) must be unique for each partition of the same
object. The subvolume name and simple file name for a new partition (whether
specified explicitly or by default) must be identical to the subvolume name and
simple file name for every other partition of the same object. ALTER TABLE
uses those names if you specify only a node name and volume name or specify
only a volume name (which causes the node to default to the local node).
A one-way split without the WITH SHARED ACCESS option requires
additional space on the disk that contains the partition being split while the split
is in progress. The amount of additional space required can be as much as the
size (EOF) of the original partition. If you are splitting a partition because the
disk is full, use the WITH SHARED ACCESS option or use a two-way split.
After a successful one-way split operation, run FUP RELOAD to reclaim
unused disk space. For more information about FUP RELOAD, see the File
Utility Program (FUP) Reference Manual.
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A two-way split moves the first part of a partition to one new partition and the
last part of a partition to another new partition, deleting the original partition:
MOVE UP TO KEY val TO dest-part
FROM KEY val TO dest-part
In a two-way split, name specifies the partition for the operation.
Both occurrences of val must be identical, but each occurrence of dest-
part must specify a different partition. That is, the combination of node name
and volume name for a new partition (whether specified explicitly as dest-
part or by default) must be unique for each partition of the same object. The
subvolume name and simple file name for a new partition (whether specified
explicitly or by default) must be identical to the subvolume name and simple file
name for every other partition of the same object. ALTER TABLE uses those
names if you specify only a node name and volume name or specify only a
volume name (which causes the node to default to the local node).
The two-way split does not support the WITH SHARED ACCESS option.
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A one-way move operation moves the first or last part of a partition to its
logically adjacent (existing) partition, leaving the other part in the existing
partition:
MOVE UP TO KEY val TO dest-part WITH SHARED ACCESS
MOVE FROM KEY val TO dest-part WITH SHARED ACCESS