Urgent question: There are 1.2 million pieces of data and 10 fields in the table, of which 3 fields are 99% empty. Is it appropriate?

  mysql, question

Full stop
Now facing a rather complicated business logic, I try to cut it off with an intermediate table-
According to preliminary estimates, this intermediate table has 1.2 million pieces of data, but for business needs, this table actually stores two types of data: one for each user, one for each week/month/quarter, and the status authentication type. (See table structure below)
Therefore, the latter category (three fields) of most data is empty. (I look at other tables in the database, there are quite a number of fields whose values are 0 or NULL, so this is the wrong decision.)

General table structure (not rigorous):
| userid | groupid | status | sales (99% empty) | createTime(99% empty) | lastTime(99% empty) | endTime(99% empty) |

Want to know:

  1. Will this empty field of data amount be correctEfficiencyInfluence?

  2. In addition to the sub-table, what elseSolutionIs it?

Do you need a back-end program to do this work? The feeling of powerlessness is full.

If the field will not be used, remove it.
If it is possible to use it, it is not a big problem to keep it, and it does not matter to specify the required fields to query when querying.