Most of the commonly used queries on the SpacePermissions table are queries on the permtype, user and group columns together, but we have no composite index on these columns.

Adding one should greatly improve performance to these queries.

This change creates very little risk, since the Space Permissions table is very rarely updated.

One large system experienced improved performance when such an index was added to its oracle database.

Note that this index might be ineffective in some systems because the column values and the query values involve NULLs, which can sometimes limit the effectiveness of an index.