Re: Minmax indexes
Jim C. Nasby <jim@nasby.net>
From: Jim Nasby <jim@nasby.net>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>,
Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2013-09-26T18:58:45Z
Lists: pgsql-hackers
On 9/26/13 12:00 PM, Robert Haas wrote: > More generally, I fear we really opened a bag of worms with this > relation fork stuff. Every time I turn around I run into a problem > that could be solved by adding another relation fork. I'm not > terribly sure that it was a good idea to go that way to begin with, > because we've got customers who are unhappy about 3 files/heap due to > inode consumption and slow directory lookups. I think we would have > been smarter to devise a strategy for storing the fsm and vm pages > within the main fork in some fashion, and I tend to think that's the > right solution here as well. Of course, it may be hopeless to put the > worms back in the can at this point, and surely these indexes will be > lightly used compared to heaps, so it's not incrementally exacerbating > the problems all that much. But I still feel uneasy about widening > use of that mechanism. Why would we add additional code complexity when forks do the trick? That seems like a step backwards, not forward. If the only complaint about forks is directory traversal why wouldn't we go with the well established practice of using multiple directories instead of glomming everything into one place? -- Jim C. Nasby, Data Architect jim@nasby.net 512.569.9461 (cell) http://jim.nasby.net
Commits
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Refactor per-page logic common to all redo routines to a new function.
- f8f4227976a2 9.5.0 cited
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Reduce use of heavyweight locking inside hash AM.
- 76837c1507cb 9.3.0 cited
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Scan the buffer pool just once, not once per fork, during relation drop.
- ece01aae4792 9.2.0 cited
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Major patch from Thomas Lockhart <Thomas.G.Lockhart@jpl.nasa.gov>
- 9e2a87b62db8 7.1.1 cited