Hello Nicolay, > > While porting an Oracle embedded SQL application to MaxDB we > have run into the following problem. With Oracle it is > possible to get a share lock on a row when a exclusive lock > on that row already exists. This makes it possible to fetch > this row in, say, session A while it is updated in session B. > When session A instead would open a cursor for update and the > exclusively locked row would be affected a lock collision > would occur. This is what we do in Oracle rigth now. I try to > port this setup to MaxDB but can't get both ends of the > circle connected as you might say.
Oracle uses a technology called 'consistent reading' meaning that provides you with the capabilities explored by your application (fetching data while it is updated, but seeing the consistent (last committed) state). As this is not the method used by MaxDB, you cannot have one for update cursor and some read access at the same time with MaxDB. If this is crucial for your application, there is little to no hope for successful porting. If you are just interested in 'some snapshot' data for a reader, and can handle 'dirty reads' you may want to lower the isolation level for the SELECT (see the documentation for 'LOCK option'). Regards Alexander Schr�der SAP DB, SAP Labs Berlin -- MaxDB Discussion Mailing List For list archives: http://lists.mysql.com/maxdb To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
