On 22 May 2012 18:41, Tom Lane <t...@sss.pgh.pa.us> wrote: > It'd be better to work on index-organized tables
My earlier analysis showed that IOTs are essentially the same thing as block-level indexes, referred to as GITs by Heikki. (Robert referred to these as Lossy Indexes recently, which was not the case - that aspect was exactly the reason for rejection previously, so we should not retread that path - indexes can operate at block level without being lossy). The number of index pointers is identical in each case, so IOTs are not any more efficient in terms of space usage or I/O. IOTs are much more difficult to implement, so I can't see any reason to work on them. For example, having heap rows migrate on a block split will cause havoc with our index implementation. We haven't worked out how to re-join blocks that have split while maintaining concurrency, so IOTs would require some pretty drastic repacking with a severe lock type. Please lets avoid IOTs. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
