December 2002
Intermediate to advanced
928 pages
85h 29m
English
HASH_MULTIBLOCK_IO_COUNT
Value: operating system dependent
Default: 1
Dynamic: ALTER SESSION
Specifies how many sequential blocks a hash join reads and writes in one I/O. When operating in multi-threaded server mode, this parameter is ignored and a value of 1 is used. The maximum value is always less than the operating system’s maximum I/O size expressed as Oracle blocks. This parameter strongly affects performance because it controls the number of partitions into which the input is divided. Obsolete with Oracle9i.