try it yourself -- it is relatively easy: perform your experiments from SQL*Plus, and use ALTER SYSTEM DUMP DATAFILE &fileno BLOCK &block to generate block dumps in a trace file... cheers, Lex. > A related question: > > Let us say there is block that contains 25 rows for a table with 2 > columns: > > RH|CL|CD|CL|CD|RH|CL|CD|CL|CD|RH|CL|CD|CL|CD|..... > -- //www.freelists.org/webpage/oracle-l