Re: [HACKERS] gsoc, oprrest function for text search

Jan Urbański wrote:
> Here's a WIP patch implementing an oprrest function for tsvector @@
> tsquery and tsquery @@ tsvector.
>
> The idea is (quoting a comment)
> /*
> * Traverse the tsquery preorder, calculating selectivity as:
> *
> * selec(left_oper) * selec(right_oper) in AND nodes,
> *
> * selec(left_oper) + selec(right_oper) -
> * selec(left_oper) * selec(right_oper) in OR nodes,
> *
> * 1 - select(oper) in NOT nodes
> *
> * freq[val] in VAL nodes, if the value is in MCELEM
> * min(freq[MCELEM]) / 2 in VAL nodes, if it is not

Seems reasonable.

> *
> * Implementation-wise, we sort the MCELEM array to use binary
> * search on it.
> */

Would it be possible to store the array in sorted order, to avoid
sorting it on every invocation of tssel?

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com

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