Changes the storage map definition for a relation.  You can also
 change which index Rdb/VMS uses when it stores new records and
 whether records will be stored in a compressed format.

Additional information available:

FormatExample

 CHANGE STORAGE MAP ───────────> map-name ────────────────────┐
 ┌─────────────────────────────<──────────────────────────────┘
 └────────────> change-relation-map-clause ──────>────────────┐
                                                              │
  ┌───────────────────────────────<───────────────────────────┘
  └──> 
E
N
D ─────┬────────>──────┬─────> typebox (S)typebox (T)typebox (O)typebox (R)typebox (A)typebox (G)typebox (E) typebox (M)typebox (A)typebox (P) ────> .
                └─> map-name ───┘

Additional information available:

map-namechange-relation-map-clause

 The name of the storage map you want to modify.

 change-relation-map-clause =

 ───────┬──┬─> store-clause ─────────────────────────┬─┬─────────>
        │  ├─> 
P
L
A
C
E
M
E
N
T 
V
I
A 
I
N
D
E
X  ──> index-name ──┤ │
        │  └────┬──> 
D
I
S
A
B
L
E ──┬─> 
C
O
M
P
R
E
S
S
I
O
N ──────┘ │
        │       └──> 
E
N
A
B
L
E ───┘                       │
        │                                              │
        └──────────────────────<───────────────────────┘

Additional information available:

PLACEMENT_VIA_INDEX

store-clauseCOMPRESSION clause

 store-clause =

 STORE ─┬──> 
W
I
T
H
I
N ─┬──> storage-area-name ────┬─────>──────────┬──>
 ┌──────┘            └───────  typebox (;) <──────────────┘                │
 │                                                               │
 └─────> 
U
S
I
N
G ───┬────> field-name ───┬── 
W
I
T
H
I
N ────>──────┐   │
                  └────────── , ───────┘                     │   │
 ┌───────────────────────────────<───────────────────────────┘   │
 └─┬─>storage-area-name ──>
W
I
T
H 
L
I
M
I
T typebox (O)F─┬> literal ─┬─ typebox (;) ──┬─┐  │
   │                                     └──── , <───┘      │ │  │
   └──────────────────────────<─────────────────────────────┘ │  │
 ┌────────────────────────────<───────────────────────────────┘  │
 │                                                               │
 └────────────────────> storage-area-name ─────────>─────────────┘

Additional information available:

WITH_LIMIT_OF

field-namestorage-area-name

 The names of the fields in the relation which are to be treated as
 keys for determining in which storage areas Rdb/VMS will initially
 store a record.

 The name of the storage area you want records stored in.  You must
 define this storage area with the DEFINE DATABASE statement before
 you refer to it in the store clause.

 The maximum value the key defined in the USING clause can have when
 it is initially stored in the specified storage area.

 The number of literals specified must match the number of fields
 specified in the USING clause.

 If you change the limits for a storage area, records that were
 already stored in the area are not moved according to the new limit
 clause.  However, new records will be stored into the relation
 according to the new limits you specify.

 Indicates that Rdb/VMS should attempt to store a record in a way that
 optimizes access to that record via the indicated path.  Rdb/VMS
 chooses a target page for any record being stored by rules that take
 into account the type of index defined (sorted or hashed), the type
 of storage areas involved (uniform or mixed), and how indexes and
 relations are assigned to each other.

 Specifies whether data compression will be enabled or disabled for
 the records when they are stored.  ENABLE COMPRESSION is the default.

 Example 1

 The following example disables compression for the CANDIDATES_MAP
 storage map:

 RDO>  CHANGE STORAGE MAP CANDIDATES_MAP
 cont>   DISABLE COMPRESSION
 cont> END CANDIDATES_MAP STORAGE MAP.

 Example 2

 The following example assigns new limits for storage areas:

 RDO>  CHANGE STORAGE MAP EMPLOYEES_MAP
 cont>  STORE USING EMPLOYEE_ID
 cont>    WITHIN EMPIDS_LOW WITH LIMIT OF "00300";
 cont>           EMPIDS_MID WITH LIMIT OF "00600";
 cont>           EMPIDS_OVER
 cont> END EMPLOYEES_MAP STORAGE MAP.

 Current data will not be moved according to the new limits.  However,
 when new data is stored, it will be stored according to the new
 limits in the storage map.