- estimate_percent in 9i
o NULL means compute
o The valid range is [0.000001,100].
o DBMS_STATS.AUTO_SAMPLE_SIZE so Oracle determines the best sample size for good statistics (Recommended value 9i and above).
I think default is AUTO_SAMPLE_SIZE.
Auto_sample_size has many problems/bugs in 9i,
When auto_sample_size is used to gather stats with dbms_stats,the SAMPLE_SIZE in dba_tables is almost equal to the NUM_ROWS.
In 9iR2, one can sepcify any percentage and it will generate stats using that percentage. Prior to oracle 9i R2, however, if the percentage was 25% or greater, then DBMS_STATS would perform 100% compute. But now in Oracle 9iR2 it can be any percentange that one need to meet your requirements.
== Search in metalink for information(for bugs about sample_size)