On Fri, Dec 8, 2017 at 2:50 PM, Alexander Korotkov < a.korot...@postgrespro.ru> wrote:
> On Thu, Dec 7, 2017 at 8:59 PM, Robert Haas <robertmh...@gmail.com> wrote: > >> On Tue, Nov 7, 2017 at 7:51 AM, Jan Przemysław Wójcik >> <jan.przemyslaw.woj...@gmail.com> wrote: >> > I'm afraid that creating a function that implements quite different >> > algorithms depending on a global parameter seems very hacky and would >> lead >> > to misunderstandings. I do understand the need of backward >> compatibility, >> > but I'd opt for the lesser evil. Perhaps a good idea would be to change >> the >> > name to 'substring_similarity()' and introduce the new function >> > 'word_similarity()' later, for example in the next major version >> release. >> >> That breaks things for everybody using word_similarity() currently. >> If the previous discussion of this topic concluded that >> word_similarity() was an OK name despite being a slight misnomer, I >> don't think we should change our mind now. Instead the new function >> can be called something which makes the difference clear, e.g. >> strict_word_similarity(), and the old function can remain as it is. > > > +1 > Thank you for pointing this. Yes, it would be better not to change > existing names and behavior, but adjust documentation and add alternative > behavior with another name. > Therefore, I'm going to provide patchset of two patches: > 1) Improve word_similarity() documentation. > 2) Add new function strict_word_similarity() (or whatever better name we > invent). > Please, find patchset attached. 0001-pg-trgm-word-similarity-docs-improvement.patch – contains improvement to documentation of word_similarity() and related operators. I decided to give formal definition first (what exactly it internally does), and then example and some more human-understandable description. This patch also adjusts two comments where lower and upper bounds mess up. 0002-pg-trgm-strict_word-similarity.patch – implementation of strict_word_similarity() with comments, docs and tests. ------ Alexander Korotkov Postgres Professional: http://www.postgrespro.com The Russian Postgres Company
0001-pg-trgm-word-similarity-docs-improvement.patch
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0002-pg-trgm-strict_word-similarity.patch
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