maria-discuss team mailing list archive

[Justin Swanhart <greenlion@xxxxxxxxx>]

You check uniqueness on the PK.  don't make a functionally dependent unique
index and you will check uniqueness only once.

On Mon, Jun 22, 2015 at 7:42 PM, Roberto Spadim <roberto@xxxxxxxxxxxxx>
wrote:

> at insert, update and replace
>
> 2015-06-22 23:39 GMT-03:00 Justin Swanhart <greenlion@xxxxxxxxx>:
>
>> Hi,
>>
>> If you do a code inspection you will find that uniqueness is checked on
>> insertion, and the database cares not about it after that.
>>
>> --Justin
>>
>> On Mon, Jun 22, 2015 at 7:20 PM, Roberto Spadim <roberto@xxxxxxxxxxxxx>
>> wrote:
>>
>>> and there's optimization with this flag? i see that equal could be
>>> optimized cause if we found 1 row we can return to user that row and stop
>>> select
>>>
>>> in other words, if i see a index with primary key or unique columns,
>>> could i change the index to unique and get some kind of performace? today i
>>> think not ,cause unique key check if it's really unique (for example at
>>> insert/update/replace), i'm wrong?
>>>
>>
>>
>
>
> --
> Roberto Spadim
> SPAEmpresarial - Software ERP
> Eng. Automação e Controle
>