It appears that the log file is not being written -- I'll start a separate thread on that issue. I reran the query. Same error, same relation, different block. dtr=> UPDATE dtr-> "DbTranRepository" dtr-> SET "userId" = UPPER("userId") dtr-> WHERE ( dtr(> ("userId" <> UPPER("userId")) AND dtr(> ("timestampValue" BETWEEN '2005-10-28' AND '2005-11-15')); ERROR: could not read block 1118215 of relation 1663/16385/16483: Invalid argument -Kevin >>> Joshua Marsh <icub3d@xxxxxxxxx> >>> Does the log file tell you anymore information? Have you tried to rerun the query? If so, did you get similar results? -Josh ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org