Re: Millions of sequence in a database to record the counter for millions of products?

Norman Dunbar wrote:
> Chao,
> are you aware that sequences can and do 'lose' values and should not be
> relied upon to produce an unbroken sequence of numbers? The following is
> an example :

hi, In fact, loose number can be easily solved by nocache option while you create the sequence:). You can do a simple test, no matter how you flush it, bouce the instance, it will not get lost. And even if it is not cached, it will be rather fast to get a count add.

  What i care the if i have that much sequence, the system tablespace   will be unacceptablly large, and never heard of any one using that   much sequence. Only with 100K sequence, my system table: SEQ$, has   grown to 13M,not knowing other system tables. SQL> select count(*) from dba_sequences where sequence_owner='SYSTEM';

  COUNT(*)

                                 100020

SQL> set serveroutput on exec show_space('SEQ$')

Free Blocks.............................5 Total
Blocks............................3206 Total
Bytes.............................13131776 Unused
Blocks...........................1025 Unused
Bytes............................4198400 Last Used Ext
FileId....................1 Last Used Ext
BlockId...................43343 Last Used
Block.........................40

PL/SQL procedure successfully completed.

--
an oracle fan, 
an oracle beginner

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