Partitioning Restrictions for Multiple Block Sizes

Use caution when creating partitioned objects in a database with tablespaces of different block sizes. The storage of partitioned objects in such tablespaces is subject to some restrictions. Specifically, all partitions of the following entities must reside in tablespaces of the same block size:

  • Conventional tables

  • Indexes

  • Primary key index segments of index-organized tables

  • Overflow segments of index-organized tables

  • LOB columns stored out of line

Therefore:

  • For each conventional table, all partitions of that table must be stored in tablespaces with the same block size.

  • For each index-organized table, all primary key index partitions must reside in tablespaces of the same block size, and all overflow partitions of that table must reside in tablespaces of the same block size. However, index partitions and overflow partitions can reside in tablespaces of different block size.

  • For each index (global or local), each partition of that index must reside in tablespaces of the same block size. However, partitions of different indexes defined on the same object can reside in tablespaces of different block sizes.

  • For each LOB column, each partition of that column must be stored in tablespaces of equal block sizes. However, different LOB columns can be stored in tablespaces of different block sizes.

When you create or alter a partitioned table or index, all tablespaces you explicitly specify for the partitions and subpartitions of each entity must be of the same block size. If you do not explicitly specify tablespace storage for an entity, then the tablespaces the database uses by default must be of the same block size. Therefore, you must be aware of the default tablespaces at each level of the partitioned object.