>1) LIST STATUS indicates that, in both instances, all of the tags and their collation sequences are identical. >2) Both .DBCs, "development" and copy of "production" data, are on the same server. >3) Both have close to the same number of records. >4) The SELECT - SQL expression ran adequately for years and is unchanged. >5) The "development" data completes in approximately 0.015 seconds > (as did the production data until last week). >6) The "production" data completes in approximately 23.6 seconds >Have you recreated the index tags from scratch to rule out corruption?