I agree, should we remove it from the TODO list? On Mon, Aug 1, 2016 at 6:13 PM, Robert Haas <robertmh...@gmail.com> wrote:
> On Mon, Aug 1, 2016 at 1:19 PM, Karan Sikka <karanssi...@gmail.com> wrote: > > Following the patch to implement strpos with Boyer-Moore-Horspool, > > it was proposed we bring BMH to LIKE as well. > > > > Original thread: > > > https://www.postgresql.org/message-id/flat/27645.1220635769%40sss.pgh.pa.us#27645.1220635...@sss.pgh.pa.us > > > > I'm a first time hacker and I found this task on the TODO list. It seemed > > interesting and isolated enough. But after looking at the code in > > like_match.c, it's clearly a non-trivial task. > > > > How desirable is this feature? To begin answering that question, > > I did some initial benchmarking with an English text corpus to find how > much > > faster BMH (Boyer-Moore-Horspool) would be compared to LIKE, and the > results > > were as follows: BMH can be up to 20% faster than LIKE, but for short > > substrings, it's roughly comparable or slower. > > > > Here are the results visualized: > > > > http://ctrl-c.club/~ksikka/pg/like-strpos-short-1469975400.png > > http://ctrl-c.club/~ksikka/pg/like-strpos-long-1469975400.png > > Based on these results, this looks to me like a pretty unexciting > thing upon which to spend time. > > -- > Robert Haas > EnterpriseDB: http://www.enterprisedb.com > The Enterprise PostgreSQL Company >
