Thread: bizgres - bizgres: 1.
Log Message: ----------- 1. Improve tuplesort.c to support variable merge order. The original coding with fixed merge order (fixed number of "tapes") was based on obsolete assumptions, namely that tape drives are expensive. Since our "tapes" are really just a couple of buffers, we can have a lot of them given adequate workspace. This allows reduction of the number of merge passes with consequent savings of I/O during large sorts. 2. Improve sorting speed by pre-extracting the first sort-key column of each tuple, as per my proposal of several days ago. Also, clean up sort memory management by keeping all working data in a separate memory context, and refine the handling of low-memory conditions. Simon Riggs with some rework by Tom Lane Modified Files: -------------- bizgres/postgresql/src/backend/utils/sort: tuplesort.c (r1.1.1.3.2.1 -> r1.2) (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/bizgres/bizgres/postgresql/src/backend/utils/sort/tuplesort.c.diff?r1=1.1.1.3.2.1&r2=1.2)