Selective expand_keywords (exact form, not infix/prefix expansion)

[barryhunter]

The new morphology_skip_fields works great. But to avoid having to modify queries manually, its useful to use expand_keywords to automatically add the exact form operator (=word).

... have just run into a problem on one my production indexes, also have min_prefix_len enabled to (with effective enable_star=1), so can do prefix matches if want, however turning on expand_keywords is transparently enabling part word matches, because word expands to (word | word* | =word)

So this is a request to be able to use enable_keywords, but ONLY get exact form expansion, not wildcard expansion.

ie so word just expands to (word | =word) - even tho min_infix_len/min_prefix_len is used

Not sure on syntax, but expand_keywords = 2 would be the easy way. But expand_keywords = exact would be more semantic. Then could also do expand_keywords = star or even star,exact.
With 1 remaining as an alias for star,exact

[tomatolog]

expand_keywords with enumeration star,exact seems good.
Do you need that option for either index config and SphinxQL option?

[barryhunter]

Well personally I only would use in it in index (ie the index has morphology_skip_fields so would add expand_keywords=exact in config)

... if want to 'disable' expand_keywords for a particular query, would then juse use ... OPTION expand_keywords=0.

Dont think would need ... OPTION expand_keywords='star,exact' - if want wildcard matches would be manually adding * in the query, rather than using expand_keywords. But ... OPTION expand_keywords=1 would work to enable for both anyway?

Also dont think need case where expand_keywords=1/0 in config and would want OPTION expand_keywords='exact' (or even just star)

[airolg]

Added to backlog, thank you

[tomatolog]

I've just pushed this feature to master branch at 9f16759

Added enumerations star,exact to expand_keywords index option along with 0\1 disable\enable
SphinxQL query option expand_keywords still enables or disables all expansions.

Documentation is on the way