To test out different physical table lay-outs, I had to repeatedly generate some test-data. After a few runs, I wanted to speed it up a bit.
Generating data: union all vs insert all
Category: I/O efficiency
As time goes by: When joins spill to disk
Large joins may use full scans and hash joins. If your tables are large enough, this will fill up your process working memory and start spilling to your temp-tablespace. At that time a few important effects come into play:
