"In production this query was taking too long, so the next step was to look at the query plan, which showed a table scan was being used instead of an index. A n

"In production this query was taking too long, so the next step was to look at the query plan, which showed a table scan was being used instead of an index. A new index was created which cut the page load time by a factor of 10." I read it as: 1) noticed that's slow in production, 2) look at query plan (prod or dev, not clear) 3) add index (not clear if they did that in dev first and then prod)