The attached patch updates README-SSI. In addition to some minor edits,
changes include:
- add a section at the beginning that more clearly describes the SSI
rule and defines "dangerous structure" with a diagram. It describes
the optimizations we use about the relative commit times, and the
case where one transaction is read-only. It includes a proof for the
latter (novel) optimization, per Heikki's request.
- note that heap page locks do not lock "gaps" like index pages
- be clear about what's been implemented (parts of the README used the
future tense, probably because they were written long ago), and
remove a couple items from the "R&D Issues" list that have since
been addressed.
Dan
--
Dan R. K. Ports MIT CSAIL http://drkp.net/