Restrictions on Secondary Indexes
The following restrictions apply to all secondary indexes.
These 32 indexes can be any combination of secondary, hash, and join indexes, including the system‑defined secondary indexes used to implement PRIMARY KEY and UNIQUE constraints.
Each multicolumn NUSI that specifies an ORDER BY clause counts as two consecutive indexes in this calculation.
You cannot define secondary indexes for a global temporary trace table. See “CREATE GLOBAL TEMPORARY TRACE TABLE” in SQL Data Definition Language Detailed Topics.