Re: unload creating duplicate versions of edited records

Not necessarily, it would also happen if the query were using an index and that index key was being modified by some users so that the row shows up again as the unload follows the btree. Art Art S. Kagel Oninit (www.oninit.com) IIUG Board of Directors (art@iiug.org) Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Oninit, the IIUG, nor any other organization with which I am associated either explicitly or implicitly. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. On Mon, Oct 19, 2009 at 10:00 PM, Andrew Clarke <aclarke@civica.com.au>wrote: > > > Hi, > > > > > > We have a 4GL program that extracts data from a table using an > > > unload. If it encounters a record that is been edited it then creates > > > 2 versions of this record, one pre-edit and one post edit. We don't > > > need a particular version of the record, as long as we only get one > > > version. > > > > > > I have never heard nor seen this behaviour before and am at a loss as > > > to what causes it and how to solve the problem. > > > > > > The program has probably set DIRTY READ ISOLATION. You want COMMITTED > READ > > or CURSOR STABILITY isolation and to SET LOCK MODE TO WAIT <nseconds> to > > avoid getting lockout errors from brief transient locks. > > > > Art > > This would presuppose that the row is being rewritten to a different > position > in the table for it to be picked up again, and that implies in-place alter > has > happened to the table, and consequently a row rewrite is taking place? > > > >