Subject RE: [firebird-support] Database design comments
Author Luis Carlos Junges
Hi Leyne,

Yah. you are right, now i saw that NTFS accept 16TB files.

Doing the backup and restore Using full page,the size is 42 MB. Really good when the size decrease.

I would like to know you approach. I did not understand it quite well. You was proposing divide brushes by properties?

The similarity is based on 30(could be more) different technical construction properties like
* Material (7 classification)
* Hole type (3 different holes)
* shoulder type (3)
* chamfer type
* insulation type
* terminal type
* shape

So, when comparing brush 1 with brush2, the first one can have a shape and the second one a different shape. So the similarity will be zero. There is a set of pre-defined values that must match in order to have a minimum level of similarity (shape,application, both with or without shunt) . After this minimal set is reached, others comparisons will be performed and the result will be a percentage stored in column similarity at the table described.

"Leyne, Sean" <Sean@...> escreveu:
> I am building a system that will be able to compare electrical brushes
> (graphite electrical brush).
> Basically the comparison will give the level of similarity and also
> highlight the differences between two brushes.
> The main problem is the quantity of brushes; i am talking about 500000
> brushes. So, i have to make 125 billions of comparisons (combinatory
> analysis C500000,2) in order to know the level of similarity among
> brushes.

I don't think I agree with your approach/reasoning.

For example to find all brushes which are identical to each other (in 1
dimension), it would be very easy get the list of distinct values and
then build a result which list the brushes which match or lists
resulting brush-pairs.

Could you please explain the types of analysis which would be required.

> * I have to store a reference for the two brushes and also the level
> similarity. I create a table like this
> |brush1(integer) | brush2(integer) | similarity (smallint) |
> ----------|
> | 500000 | 34999 | 98
> |
> | 365 | 34999 | 99
> |
> | 1000 | 349 | 56
> |
> | 1000 | 365 | 75
> |

Is similarity determined/calculated using one or multiple factors?

Can you explain how similarity is determined/calculated?


Luís Carlos Dill Junges ©

"A realidade de cada lugar e de cada época é uma alucinação coletiva."
Bloom, Howard

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