Breaking down values in a large table

[John Hallas]

Listers, I have a table of 125M rows (not partitioned) which I am exporting. I want to break the export into 4 dmp files using the query command on the pk column.   I am looking at how the best way of finding the values of the PK (number) which are at 25%, 50% and 75% ish for the table so that I can get 4 evenly sized exports   My query line in the parameter file will be along the lines of where 1)       log_no < xx 2)       log_no >= xx and < yy 3)       log_no >= yy and < zz 4)       log_no >= zz   I am thinking of a sql something like the following   Select /*+  index ffs(table_name index_name) */ Log_no , floor(log_no / 4), count(*) From table_name group by floor(log_no / 4), log_no   Version is 8.1.7.1   Can anybody help please   Thanks   John