When the best effort resequencer is configured to use a time window instead of a maximum number rows, the messages to select and process at one time are based on a period you specify plus an optional buffer time. Each message belongs to a specific time window, and messages that are part of one time window are processed separately from messages belonging to a different time window.

In addition to the time window, you can specify a buffer time, which is an overlap between two sequential time windows that allows messages that arrive a little late to be associated with the first time window. By default, the buffer time is 10% of the time window you specify.

When the best effort resequencer is configured to use a time window, groups are processed in an iterative manner and messages are processed in the following steps:

1. The first message arrives and the time window begins.

2. The buffer is added to the time window, and processing begins after the buffer time.

3. The resequencer retrieves the messages that arrived within the time window, and identifies the maximum sequence ID (typically a date and time stamp) from all the messages.

4. The resequencer retrieves any messages that arrive within the buffer time and that have a sequence ID that is less than the maximum sequence ID identified above.

5. The resequencer sorts all messages retrieved in the above steps in ascending order of the sequence IDs and processes the messages.