Concurrent DML access to a table does not use global indexes while a partition-level operation is in progress on the table. SAP ASE uses alternate local index scan or table scan for concurrent DML scans.
Multiple partition-level operations on different partitions can operate concurrently. Each one does not perform global index rebuild. Only the last committed partition-level operation performs global index rebuild.
The last partition-level operation leading to abort may result in global index marked as suspect. The global index in such case has to be explicitly rebuilt.