I used to be a number of practitioners, but to do several positions for so many years, there has been a concept is not clear,

We usually said several positions, would say the more classic relationship modeling or dimensional modeling a methodology, but recently often see inside some hiring jd information modeling [upon] such a word,
I'm not sure this modeling [upon] is what kind of a theory?

I only know that we are building a data warehouse, do the specific model design, is to [subject-oriented] and then according to the actual system environment of application scenarios and choose specific creation methods, such as in the dimension modeling is to use a star or snowflake (usually two hybrid), so I'm a little confused,

Also please great god can give me solution,

My understanding is that this is just a business level, similar to the subject-oriented we say, in the actual operation is the model in the application layer of organization form, do not know, right?


I hope comment, please do not copy and paste, baidu has access to a lot of data in baidu, said popular point as far as possible, thank you ~

CodePudding user response:

About subject-oriented

1. Its purpose is to support can be in different domain analysis, the assessment scheme can achieve interdisciplinary business;
2. To provide data on the business object (subject),

about star model snowflakes model, the galaxy model

As you say, we often use a mixture of star and snowflake mode, namely the Galaxie - Schema, and under certain conditions, it doesn't matter you choose to be a star, snow or the Milky Way, because it depends on our analysis of the data, our focus and we want to achieve the effect of,

For example, if we need to consider the storage costs, then the number of dimensions, classification of series in more than a certain amount of time, snowflake model will be a few times the star model, but we don't need too complex analysis, so star natural is the best, and less classification series, storage costs little,

According to the change of demand, the emphasis is different, choose also in change, still need to choose according to realistic condition to measure the specific patterns,

There may be some ambiguity, but the hope can help you