update statistics - large amount of log space

I am getting problems with update statistics and the amount of log space used. We are filling 14 logs of 20Mbytes each time that we run update statistics medium. The system has a number of databases and their are 44,554 tables in the whole system. I also checked and their are a total of 36,000 sysdistrib records. The row size for systables is 469 so the amount of log space needed for systables is 44,554 * 2 * 469 plus about 10% overhead. The row size for sysdistrib is 305 so the amount of log space needed for that is 36,000 *2 *305 plus about10% overhead. The calculation can account for about 70 Mbytes whereas we ar using 280 Mbytes. What else does update statistics change? regards Malcol,m sending to informix-list