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Re: doubt about index



b+tree search is binary search, which is divide and conquer.  Saving
scanning a key is like sneezing in a hurricane, you still are o(log(n)) in.

On Mon, Jun 22, 2015 at 7:39 PM, 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?

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