Oracle技术专题

Cluster

The standard of wrong or correct by no means of who said and what his/her name, especially in software industries, the rule is “ SHOW ME THE CODE”.  If you can’t access the code sources of modules Ktl.c, Ktr.c, Ktu.c, of Oracle 7.3 we better stop this worthless discuss, since we never will be on the same page.

风清阳

如何测试一个事务undo信息的大小：       
        drop table stats$undo_begin;
        drop table stats$undo_end;
        --create the set up tables
        create table stats$undo_begin(writes number);
        create table stats$undo_end(writes number);
       
        --start values
        insert into stats$undo_begin
        select sum(writes) from v$rollstat
        where usn=(select usn from v$rollname where name='R04');
       
        commit;
        set transaction use rollback segment R04;
        --execute large transaction
       
        @large_batch_job;
       
        insert into stats$undo_end
        select sum(writes) from v$rollstat
        where usn=(select usn from v$rollname where name='R04');
       
        --end  values       
        select (e.writes-b.writes) undo_generated
                from  stats$undo_begin b,stats$undo_end e       

        initora.ora文件中参数transactions_per_rollback_segment 参数决定一个回滚段可进入事务数目。
        回滚段数目及大小的确定方法：
        size_of_rollback=transactions_per_rollback_segment*每一事务平均大小
       
        number_of_rollback=transactions(并发事务个数)/transaction_pre_rollback
        说明：事务并发个数授initora.ora中参数transactions限制。

风清阳

//请问那位有这方面的资料不

风清阳

同志们给点面子吗