Re: grep -f keyword data query

On 30 December 2015 at 04:21, Hiroyuki Sato <hiroysato@gmail.com> wrote:

2015年12月29日(火) 4:35 Jeff Janes <jeff.janes@gmail.com>:

 

But, the planner refuses to use this index for your query anyway,
because it can't see that the patterns are all left-anchored.

Really, your best bet is refactor your url data so it is stored with a
url_prefix and url_suffix column.  Then you can do exact matching
rather than pattern matching.

I see, exact matching faster than pattern matting. 

But I need pattern match in path part 

(ie, http://www.yahoo.com/a/b/c/... )

 I would like to pattern match '/a/b/c' part. 

If your pattern matching is as simple as that, then why not split the /a/b/c/ part out as mentioned by Jeff? Alternatively you could just write a function which splits that out for you and returns it, then index that function, and then just include a call to that function in the join condition matching with the equality operator. That'll allow hash and merge joins to be possible again. 

 

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