How does increasing the number of selected columns in the SELECT * operator affect query execution speed?

Increasing the number of selected columns in the SELECT * operator directly affects query execution speed and system load:

• The more columns are selected, the more data needs to be read from disk and transmitted over the network.
• This increases query processing time, especially if the table is large and contains heavy data types.
• If the application only uses part of the data, selecting all columns leads to unnecessary load and reduced performance.

Therefore, it is recommended to explicitly specify only the necessary columns in SELECT to minimize the amount of data transmitted and speed up query execution.