During the sorting process,
SPD Server writes blocks of sorted rows (called spill bins) to disk. The final step of the process
reads the contents of the spill bins to perform final row ordering. BINBUFSIZE= specifies
the amount of memory that is allocated to each spill bin during final row ordering.
The spill bins use the memory buffer to read rows back into memory during interleaving.
The number of spill bins depends on the size of the table, the amount of memory specified
on SORTSIZE=, and the number of threads that SPD Server uses to perform sorting. For
example, if you sort a 10-GB table using two concurrent
threads, and SORTSIZE=2 GB, the SORTSIZE= value is divided between the two concurrent
threads. Each
thread reads 1 GB of row data from the table into memory. In this case, each 1-GB
block of row data makes up a spill bin. The rows in the spill bin are sorted and then written
to disk. After all of the rows in the table have been sorted and written to disk,
the sorting process reads the spill bins back into memory for final processing. In
the example, a total of 10 spill bins and 10 buffer areas interleave the sorted rows.