The workspace keeps changes to the data only to minimize the size of the workspace
data and avoid data duplication.
Youcan have a hierarchy of workspaces, and a workspace can have more than one
parent. All workspace operations, described in the next sections, affect a workspace
and its parent workspaces. Multiple levels of workspaces can give you finer granularity
on the isolation of changes for workspace-enabled tables.
Oracle implements workspaces by adding metadata to the rows of a table. This metadata
can include a timestamp as to when a change was made, which can help in analysis
of workspace activity. This option works with savepoints to provide a history of
changes made to each row version created by a savepoint. The timestamp allows
users in a workspace to go back to any point in time and view the database from the
perspective of changes made in that workspace up to another point in time. You can
think of this as a type of Flashback (described in Chapter 3) for a limited set of
tables.
In addition, youcan specify that a particular version of data in a workspace is valid only
for a specific time period.
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