> Roberts, Jon escribió: > > > Why would you set the fillfactor to anything other than 100 for a > > PostgreSQL table? > > To favor HOT updates. > > -- I can find very little information on hot updates but I found this: http://archives.postgresql.org/pgsql-patches/2006-11/msg00059.php It states, "This design optimizies the updates when none of the index columns are modified and length of the tuple remains the same after update." How can a row's length change? I think it must mean the size (in bytes) of the row remains the same. If this is the constraint, then I still don't see the benefit. If the size can vary, I can see the benefit because the new column value may be larger than the old value thus needing the space. Why isn't the hot update documented in these locations? http://www.postgresql.org/docs/8.3/interactive/sql-createtable.html http://www.postgresql.org/docs/8.3/interactive/sql-update.html http://www.postgresql.org/docs/8.3/interactive/sql-altertable.html Jon
