Hi, I have a simple query:
SELECT first 1 ITEM_DATE FROM HISTORY WHERE ITEM_ID = 'ITEM_ID_123456' and ITEM_TYPE = 'TYPE1' AND ITEM_STATUS > 200 and ITEM_STATUS <> 310 ORDER BY ITEM_DATE ASC Which runs in about 1.5 seconds. If I remove the Order by it's less than 100ms. There are only three records in the result set. There is an ascending index on ITEM_DATE and the statistics are up to date. Does anyone know why there would be such a difference in performance when using\not using the order by? What is the engine ordering? It can't be the three records to take 1.5 seconds, surely? Thanks,
