Replication Server attempts to group similar transactions to process them as one, larger transaction.
The next transaction has been issued from a different origin.
The number of transactions in the group exceeds the value specified by dsi_max_xacts_in_group.
The total size, in bytes, of the transactions in the group exceeds the value specified by dsi_xact_group_size.
The next transaction is a large transaction, which is always grouped by itself.
A transaction partitioning rule determines that the next transaction cannot be grouped with the existing group.
Once a group is complete, it can be sent to the next available DSI executor thread. Only committed transactions can be added to a group. That is, transactions are not added to the transaction group until their commit record is read.