Whenever we startup the database, we see the memory allocations for SGA. But most of the times, I have observed that the logbuffer size is differnt from the parameter log_buffer in the INITSID.ora file. Can anybody tell me what do we exactly mean by fixed and variable sizes. How much of fixed size is allocated for an instance? Also V$SGAS?TAT figures sometimes do not match with tha INITSID.ORA parameters. Thanks for any information given.