Re[2]: [HACKERS] SERIAL data type

Hello Billy,

sabato, 12 settembre 98, you wrote:

BGA> t-ishii@sra.co.jp (Tatsuo Ishii) writes:
>> A few questions for new SERIAL data type:
>>               [...]
>> o explicit insertion to the serial column sets the value specified.
>>   This is good. However, next implicit insertion results in that
>>   previous value from the sequence + 1 is set.
>>
>>   create table t (c text, i serial);
>>   insert into t values('a');
>>   insert into t values('b',100);
>>   insert into tvalues('c');
>>   select * from t;
>>
>>    a   1
>>    b    100
>>    c    2
>>
>>   This seems a little bit unnatural for me. may be i of the thrid row
>>   should be 101?

BGA> The action above is definitely 'not right'.  It is my opinion that either:

BGA>     1.  Explicit insertion into a serial column be dis-allowed.
BGA>     2.  If explicit insertion is allowed, then the sequence need to be set so
BGA>         the next implicit insertsion result in the last explicit insertion
BGA>         value + 1 being used (i.e. 101 instead of 2 in the example above).

BGA> Of these two options, I prefer #1.

BGA> Also, should we be able to specify a starting value for the sequence when the
BGA> table is created?  For example "create table t (c text, i serial(1000));" to
BGA> set the starting value of the sequence to 1000.

I would like to remember there's another problem with sequences.
If you increment a sequence during a transaction and then the transaction
rolls back, the sequence's original value don't be restored.

            Jose'