Oracle10g Coalescing a New Partition
The COALESCE operation reduces one of the index partitions,
which are partitioned using the hash method. This method
redistributes index entries of an index partition determined by
the hash function, and then destroys the selected partition. This
method is almost the inverse of the ADD partition operation.
SQL> ALTER INDEX parts1_hgidx
2 COALESCE
PARTITION PARALLEL ;
Index altered.
The above operation removes one partition as seen in the output
below:
SQL> select index_name, partition_name,
tablespace_name, status from user_ind_partitions where index_name
like 'PART%';
INDEX_NAME PARTITION_NAME TABLESPACE_NAME STATUS
------------- ----------- ---------------
-------
PARTS1_HGIDX SYS_P4
USERS USABLE
PARTS1_HGIDX SYS_P5
USERS USABLE
PARTS1_HGIDX SYS_P6
USERS USABLE
So far, we have examined the improvements in Oracle 10g in
terms of partitions and related facilities. In the next section,
we will examine changes that are introduced in the hash clusters. |
