Consolidated Database Replay enables you to transform existing workload captures into new, smaller pieces of capture subsets. You can then generate new workload captures from the capture subsets that can be used in different use cases, as described in "Use Cases for Consolidated Database Replay".
A capture subset is a piece of a workload capture that is defined from an existing workload capture by applying a time range. The time range is specified as an offset from the start of the workload capture. All user workloads captured within the specified time range are included in the defined capture subset.
For example, assume that a workload was captured from 2 a.m. to 8 p.m. and the peak workload is identified to be from 10 a.m. to 4 p.m. You can define a capture subset to represent the peak workload by applying a time range that starts at 8 hours after the start of the workload (or 10 a.m.) and ends at 14 hours after the start of the workload (or 4 p.m.).
However, if a capture subset only contains recorded user workloads that satisfy the specified time range, user logins that occurred before the specified time range are not recorded. If these user logins are required for replay, then the capture subset may not be replayable. For example, if a user session starts at 9:30 a.m. and ends at 10:30 a.m. and the specified time range for the capture subset is 10:00 a.m. to 4:00 p.m., the replay may fail if the user login at 9:30 a.m. is not included in the workload. Similarly, the specified time range may also include incomplete user calls that are only partially recorded if a user sessions starts at 3:30 p.m. but does not complete until 4:30 p.m.
Consolidated Database Replay addresses this problem by including only incomplete user calls caused by the start time of the specified time range. To avoid including the same incomplete user calls twice if the workload capture is folded, incomplete user calls caused by the end time are not included by default. Therefore, a capture subset is essentially the minimal number of recorded user calls during a specified time range that are required for proper replay, including the necessary user logins, alter session statements, and incomplete user calls caused by the start time.