* Micah Stevens <micah@xxxxxxxxxxxxxxxxxx>: > Sounds like a self join should work wonders. > > I didn't test this, but the idea should work: > > > select t1.app_id as a1, t2.app_id as a2, t2.word, t2.score > from tablename as t1 > left join tablename as t2 > on t1.resource_id = t2.resource_id and t1.app_id != t2.app_id > group by word > order by word > > voila, no temp tables. Am I missing something? Speed. :-) I had tried this as well. The temporary tables really do offer much better performance. The issues I was having were (1) bad resultsets (I've now got that fixed) and (2) speed. I still don't have (2) completely fixed, and it may be something I can't fix. > On Thursday 10 February 2005 07:56 pm, Matthew Weier O'Phinney wrote: >> I have a table which contains the following: >> id (primary key, auto incrementing) >> app_id (integer, foreign key) >> resource_id (integer, foreign key) >> word >> score > > >> (This is a search index.) I want to find all resource_ids from one app_id >> that match resource_ids in another app_id by word. > > >> I have created a temporary table 'tmp1' that contains all resource_ids >> from the second app_id (the one whose resources I wish to retrieve). I >> am then looping through all resource_ids in the main table with the >> first app_id, and doing the following: > > >> * Creating a temporary table tmp2 with a single column 'word' >> populated by the words associated with resource_id in the main >> table >> * Selecting all distinct resource_ids from tmp1 INNER JOIN'd on tmp2 >> on the word field > > >> The issues I'm running into are that (1) each resource_id cycle takes a >> good amount of time, and (2) I seem to be getting either too many >> resource_ids or not enough. > > >> (1) may be something I just have to deal with. As it is, I'm planning on >> running the full indexing once, and then doing incremental updates, so >> it may not be that big of an issue (unless it takes too much time to >> create the initial index). As for (2), unfortunately, I'm not sur ehow >> to really trouble shoot the issue. I know, for instance, that in once >> case, I have a list of 343 words that generates a list of ~12,000 >> resource_ids (of a possible 18,000) -- but I don't quite know how to >> spot check 300 values to be certain that this is reasonable. > > >> In a previous incarnation of the script, I was looping through each word >> of each resource_id and then selecting out of tmp1 based on the single >> word value. The results were very different (very few matches), and, >> again, the script ran long. > > >> Any ideas? -- Matthew Weier O'Phinney | WEBSITES: Webmaster and IT Specialist | http://www.garden.org National Gardening Association | http://www.kidsgardening.com 802-863-5251 x156 | http://nationalgardenmonth.org mailto:matthew@xxxxxxxxxx | http://vermontbotanical.org -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
