Extract Sessions
- Last UpdatedApr 22, 2025
- 1 minute read
When an extract is created, it is created at a particular session number in the parent extract. This is called the linked session. As the parent extract is modified, that is, as new sessions are added, the linked session on the new extract will not change until a refresh or flush is made.
Each extract session will be linked to a specific session in the parent database. This linked session will only change as a result of a refresh.
Note:
Issuing and dropping cause an automatic refresh.
This is best illustrated by the following example.
When a user is making local changes only, the linked session number stays the same. When the user does a refresh, the extract is linked to the most recent version of the parent database.
The session number in the parent database will reflect SAVEWORK commands in the parent itself, and also flushes done by users of other child extracts.
Example:
|
Extract session number |
Linked session number in owner |
Comment |
|---|---|---|
|
1 |
10 |
Extract created. |
|
2 |
10 |
Modification made on extract. |
|
3 |
10 |
Modification made on extract. |
|
4 |
15 |
Meanwhile, other changes have been made to the owing database, taking it to session 15. When the extract user does a refresh, the linked session becomes session 15. |
|
5 |
15 |
Further modification of extract. |
|
6 |
18 |
When the extract changes are issued, the owning database is at session 18, which becomes the linked session due to an implied refresh. |
|
7 |
18 |
Further modification. |
|
8 |
18 |
Further modification. |
|
9 |
25 |
Issued back. |