如何加速复杂的MYSQL查询？

Question

I have the following MYSQL query in a Cold Fusion Component being called from a ColdFusion website. I have a custom take that basically builds a boolean query for the following fields: "PlaceName,Country,Adm1,adm2,adm3,locality".

<!--- SEARCH PLACES 2--->
<cffunction name="searchPlaces_full" access="public" returntype="query">
    <cfargument name="q" type="string" required="yes">


    <CF_BOOLSEARCH searchterm="#arguments.q#" field="PlaceName,Country,Adm1,adm2,adm3,locality " booloperator="and">
    <cfquery name="GetPlaces" datasource="#application.settings.dsn#">
    SELECT 
        places.CatID,
        places.PlaceName,
        places.PlaceID,
        places.Address1,
        places.PostalCode,
        places.Locality,
        places.Address2,
        places.ImageThumb,
        places.Adm1,
        places.Country,
        places.Adm2,
        places.Adm3,
        places.contributorid,
        places.lng,
        places.lat,
        places.verified,
        places.verified_by,
        places.verified_date
    FROM places INNER JOIN places_cats ON places.PlaceID = places_cats.PlaceID
    WHERE  
    <cfif len(trim(arguments.q))>
    (#PreserveSingleQuotes(boolsearch)#)
    <cfelse>
    1=0
    </cfif>
    AND places_cats.CATID IN (#arguments.categories#)
    GROUP BY 
        places.CatID,
        places.PlaceName,
        places.PlaceID,
        places.Address1,
        places.PostalCode,
        places.Locality,
        places.Address2,
        places.ImageThumb,
        places.Adm1,
        places.Country,
        places.Adm2,
        places.Adm3,
        places.contributorid,
        places.lng,
        places.lat,
        places.verified,
        places.verified_by,
        places.verified_date
        ORDER BY PlaceName
        </cfquery>


    <cfreturn getPlaces>
</cffunction>

There are 624227 records in the database. If I do a search for Chappaqua, the actually SQL that gets run is as follows:

       SELECT 
        places.CatID,
        places.PlaceName,
        places.PlaceID,
        places.Address1,
        places.PostalCode,
        places.Locality,
        places.Address2,
        places.ImageThumb,
        places.Adm1,
        places.Country,
        places.Adm2,
        places.Adm3,
        places.contributorid,
        places.lng,
        places.lat,
        places.verified,
        places.verified_by,
        places.verified_date
    FROM places INNER JOIN places_cats ON places.PlaceID = places_cats.PlaceID
    WHERE  

    (((PlaceName LIKE '%chappaqua%') OR (Country LIKE '%chappaqua%') OR (Adm1 LIKE '%chappaqua%') OR (adm2 LIKE '%chappaqua%') OR (adm3 LIKE '%chappaqua%') OR (locality  LIKE '%chappaqua%')))

    AND places_cats.CATID IN (1,21,15,32,16,26,29,27,28,25,75,89,38,5,36,88,87,31,33,24,35,37,90,39,40,34,30,9,8,7,11,20,19,96,97,95,13,17,14,12,3,2,4,84,85,86)
    GROUP BY 
        places.CatID,
        places.PlaceName,
        places.PlaceID,
        places.Address1,
        places.PostalCode,
        places.Locality,
        places.Address2,
        places.ImageThumb,
        places.Adm1,
        places.Country,
        places.Adm2,
        places.Adm3,
        places.contributorid,
        places.lng,
        places.lat,
        places.verified,
        places.verified_by,
        places.verified_date
        ORDER BY PlaceName

I know it is ugly and complex. It takes about 1836ms to run. Is there any better way to write the query or code so that it speeds up the returned data in under a second?

Here is the Explain on the SQL:

Answer 1

The problem is that the engine is doing a full table scan of the table, then sorting the results for the group by .

The full table scan almost seems necessary because of the like s:

(((PlaceName LIKE '%chappaqua%') OR (Country LIKE '%chappaqua%') OR (Adm1 LIKE '%chappaqua%') OR (adm2 LIKE '%chappaqua%') OR (adm3 LIKE '%chappaqua%') OR (locality  LIKE '%chappaqua%')))

The issue is that an index on PlaceName cannot be used, because the initial characters are not fixed.

So . . . Can you remove the group by ? You can at least replace it with distinct , although I don't think that would affect the query plan. Do you have an index on place_cats(placeId, catId) ? That would at least prevent the query from reading the category table so it could just do index lookups.

Can you limit the search only to words at the beginning of the fields?

The only other alternative that I can think of is to switch to using a full text index in MySQL.