extents and system tables

Hello! My cursory check of TFM turned up nothing so I am turning to all of you. Our production db has several system tables that are approaching the 30 extent range. I'd like to bring this down to a reasonable size (if it useful). Q1: Is it necessary or helpful? Q2: What is the best way to modify a system table? Can you unload a system table, drop and re-create it just as a user table? Note, I'll be doing this in conjunction with extent modifications using dbload of other tables... tia Doug

adiosadios wrote: > > Hello! My cursory check of TFM turned up nothing so I am turning to all of > you. > > Our production db has several system tables that are approaching the 30 > extent range. I'd like to bring this down to a reasonable size (if it > useful). DON'T!!!!!! > Q1: Is it necessary or helpful? Neither. > Q2: What is the best way to modify a system table? Can you unload a system > table, drop and re-create it just as a user table? No you cannot. Not an keep your data anyway. > Note, I'll be doing this in conjunction with extent modifications using > dbload of other tables... Don't do it. The extents of the system catalog tables cannot affect performance unless the data dictionary cache is too small (onstat -g dic to see size and contents). All dictionary records for active tables are kept in the cache and so the disks are not accessed normally. You can adjust the size of the cache using DD_HASHSIZE and DD_HASHMAX. The former must be a prime integer specifying the number of hash buckets and the latter a small integer specifying the number of slots in each bucket. Art S. Kagel