Query Optimization - Equality VARCHAR vs Numeric Equality

Question

I have a large SQL Server database with approximately 40 columns and hundreds of millions of rows.

This table should be free in the schema, so I have many columns like VARCHAR (MAX), even if it can be BIGINT, DATETIME, INT, etc. Does it affect time / performance requests? for example will

SELECT TOP 100 * FROM CustomerId = 34343

will be faster than

SELECT TOP 100 * FROM CustomerId = '34343'

? If so, how much faster?

But what if I use VARCHAR (MAX) instead of a fixed length VARCHAR. What about other databases like mySQL etc. In this respect?

Answer 1

, , . , , , . , , . . .

Answer 2

, INT VARCHAR (MAX) . .

, VARCHAR(MAX) - , !

:

• Varchar (MAX)

- , VARCHAR (MAX) - , ...

Answer 3

, VARCHAR (MAX) VARCHAR.. , mySQL .. ?

• PostgreSQL VARCHAR(n) TEXT CHECK(LENGTH(Column) <= n). .
• SQLite VARCHAR.
• MS SQL Server, , VARCHAR(MAX), .