Hvordan kan jeg fremskynde denne SELECT CONCAT/GROUP BY-forespørgsel?

Opret et sammensat indeks på (state, city) og omskriv din forespørgsel som denne:

SELECT  CONCAT_WS(', ', city, state) AS location, AVG(latitude), AVG(longitude) 
FROM    places
WHERE   state='NY'
        AND city='New York'
GROUP BY
        state, city

Bemærk, at for netop denne forespørgsel kan du udelade GROUP BY klausul:

SELECT  'New York, NY' AS location, AVG(latitude), AVG(longitude) 
FROM    places
WHERE   state='NY'
        AND city='New York'

Denne forespørgsel har dog stadig brug for den:

SELECT  CONCAT_WS(', ', city, state) AS location, AVG(latitude), AVG(longitude) 
FROM    places
WHERE   state='NY'
GROUP BY
        state, city