在网上差了一下才知道是_partition_large_extents参数导致的。从11.2.0.2开始,创建分区表,每个分区默认大小为8M,是由_partition_large_extents参数控制,可以算是11.2.0.2开始的一个新特性,为了减少extent数量,提高分区表性能,而设置的一个参数,默认为true,即分区表的每个extent为8M。测试一下: 确保deferred_segment_c...
11.2.0.2中引入了_partition_large_extents 的新特性,在extent size auto allocate的表空间上若创建分区表,则分区的initial extent size为8M。 试看下面的例子: _partition_large_extents TRUE Enables large extent allocation for partitioned tables _index_partition_large_extents FALSE Enables large extent allocatio...
11.2.0.2中引入了_partition_large_extents 的新特性,在extent size auto allocate的表空间上若创建分区表,则分区的initial extent size为8M。 试看下面的例子: _partition_large_extents TRUE Enables large extent allocation for partitioned tables _index_partition_large_extents FALSE Enables large extent allocatio...
I've seen some blogs recommending that _partition_large_extents be set to FALSE for a variety of space conserving reasons without the authors thinking about the negative impact this is going to have on Smart Scan. Large Extents cause an INITIAL allocation of 8 MB and a NEXT allocation of 1...