Re: Logical log size

Stefan Weideneder wrote: > > Hi Carlson, > > first of all, rows that will not be changed during an update > operation will not be logged, that is, if you set a field's value > to the same value it contained before, this will not be marked > as an update and therfore will not be logged in the logical logs. > Makes sense . . . but I'll be updating every row. > If you change the value of an indexed column, if have no idea > of the costs in the logical log files ( you might check it yourself > by using "onlog -l -n #" ). For non-indexed columns the > adminsitrative overhead of an ordinary update will be about > 36 Bytes plus the modified bytes times 2 ( at least 4 Bytes ) per row. > Some of these updates will include columns within indices. > My guess in your case : > > Number of rows modified * ( 36 + ( 2 smallints = 4 * 2 = 8 ) ). > > Number of rows modified * 44 Bytes. > > Uhps, I forgot the BEGIN WORK and COMMIT WORK. I think they will > cost about 20 + 20 = 40Bytes. > > I think it's better if you have a detailled look into the logical > log files as mentioned above. > I was afraid that you'd say that. > Bye > > Stefan Weideneder > Thanks! John Carlson Informix DBA WH Smith, Inc.