Re: Zedstore - compressed in-core columnar storage
От | Tomas Vondra |
---|---|
Тема | Re: Zedstore - compressed in-core columnar storage |
Дата | |
Msg-id | 20190414171233.vhukbvlfwnacc37u@development обсуждение исходный текст |
Ответ на | Re: Zedstore - compressed in-core columnar storage (Andres Freund <andres@anarazel.de>) |
Список | pgsql-hackers |
On Sun, Apr 14, 2019 at 09:45:10AM -0700, Andres Freund wrote: >Hi, > >On 2019-04-14 18:36:18 +0200, Tomas Vondra wrote: >> I think those comparisons are cute and we did a fair amount of them when >> considering a drop-in replacement for pglz, but ultimately it might be a >> bit pointless because: >> >> (a) it very much depends on the dataset (one algorithm may work great on >> one type of data, suck on another) >> >> (b) different systems may require different trade-offs (high ingestion >> rate vs. best compression ratio) >> >> (c) decompression speed may be much more important >> >> What I'm trying to say is that we shouldn't obsess about picking one >> particular algorithm too much, because it's entirely pointless. Instead, >> we should probably design the system to support different compression >> algorithms, ideally at column level. > >I think we still need to pick a default algorithm, and realistically >that's going to be used by like 95% of the users. > True. Do you expect it to be specific to the column store, or should be set per-instance default (even for regular heap)? FWIW I think the conclusion from past dev meetings was we're unlikely to find anything better than lz4. I doubt that changed very much. regard -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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