Overview of Partitioned Indexes

Just like partitioned tables, partitioned indexes improve manageability, availability,
performance, and scalability. They can either be partitioned independently (global
indexes) or automatically linked to a table's partitioning method (local indexes). In
general, you should use global indexes for OLTP applications and local indexes for
data warehousing or DSS applications. Also, whenever possible, you should try to use
local indexes because they are easier to manage. When deciding what kind of
partitioned index to use, you should consider the following guidelines in order:

1. If the table partitioning column is a subset of the index keys, use a local index. If
this is the case, you are finished. If this is not the case, continue to guideline 2.
2. If the index is unique, use a global index. If this is the case, you are finished. If this
is not the case, continue to guideline 3.
3. If your priority is manageability, use a local index. If this is the case, you are
finished. If this is not the case, continue to guideline 4.
4. If the application is an OLTP one and users need quick response times, use a
global index. If the application is a DSS one and users are more interested in
throughput, use a local index.

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