The Snapshot object is defined in the same way as the view table. The data of a Snapshot exists in the form of a (read-only) copy that is typically located on a different computer from the base tables. Basically, Snapshots are used decentrally in order to access partial datasets from productive applications at defined times. Snapshots are updated explicitly using the REFRESH statement (see the ADABAS Reference manual).
Relationship between a snapshot and other objects:
1. Snapshot Contains Column
2. Snapshot Uses Synonym
3. Snapshot Uses Table
4. Snapshot Uses View
5. Easycommand Uses Snapshot
6. Easyform Uses Snapshot
7. Module Uses Snapshot
8. Qpcommand Uses Snapshot
9. Qpquery Uses Snapshot
10. Querycommand Uses Snapshot
11. Synonym Refers to Snapshot
12. User Uses Snapshot
13. View Uses Snapshot
1. A snapshot comprises one or more columns; a snapshot column is uniquely assigned to a snapshot (1-N).
2. A snapshot can refer to a number of synonyms; a synonym can be used by a snapshot (N[0]-M[0]).
3. A snapshot refers to one or more tables; a table can be used by a snapshot (N[0]-M).
4. A snapshot can refer to a number of view tables; a view table can be used a snapshot (N[0]-M[0]).
5. An EASY command can use a number of snapshots; a snapshot can be used by an EASY command (N[0]-M[0]).
6. An EASY form can use a number of view tables; a view table can be used in an EASY form (N[0]-M[0]).
7. A module can use a number of snapshots; a snapshot can be used by a number of modules (N[0]-M[0]).
8. A QueryPlus command can use a number of snapshots; a snapshot can be used by a number of QueryPlus commands (N[0]-M[0]).
9. A QueryPlus query can use a number of snapshots; a snapshot can be used by a number of QueryPlus queries (N[0]-M[0]).
10. A QUERY command can use a number of snapshots; a snapshot can be used by a number of QUERY commands (N[0]-M[0]).
11. A synonym can refer to a snapshot; a number of synonym definitions can exist for a snapshot (N[0]-1[0]).
12. A user can use a number of snapshots; a snapshot is used by one or more users (N-M[0]).
13. A snapshot refers to one or more tables; a table can be used by a snapshot (N[0]-M).
A Snapshot can be handled like any other table and, as such, has the same structure and relationships to other objects as described for Table (see Section Table). The procedure for creating, viewing (Relships / Object Usage / Colunns function), and deleting a Snapshot definition (see Section View) is the same as for a view definition. The Snapshot definition determines the relationship between Snapshot and Table and between Column and Column.