Advantages and disadvantages of paradigm and inverse paradigm

In the design of the database, there are paradigms and anti-paradigm of stress, summarized below.

Advantages of the paradigm:

1) The normalized database is updated more quickly;

2) After normalization, only a small number of duplicate data, only need to modify less data;

3) The normalized table is smaller and can be executed in memory;

4) Less redundant data, requiring fewer distinct or group by statements when querying.

Disadvantages of the paradigm:

5) A normalized table that often requires a lot of correlation when querying, because there is no redundant and duplicate data in a single table. This results in a slightly more complex query statement that may require more than a few associations on the schema of the query paradigm. This increases the cost of making the query, and may invalidate some index policies. Because normalization stores columns in different tables, these columns can belong to the same index in a table.

Advantages of inverse paradigm:

1) can avoid association, because all the data can be displayed on a single table;

2) A valid index can be designed;

Disadvantages of the inverse paradigm:

3) More redundancy in the table, the deletion of data will cause the table some useful information is lost.

Therefore, when designing the database, we should pay attention to the mixed use of normalization and inverse normalization.

Advantages and disadvantages of paradigm and inverse paradigm