A query uses SELECT * to retrieve all 20 columns from a table, but the application only displays 3 of those columns. Which of the following correctly describes why this pattern increases energy consumption?

Question

Accepted Answer

All 20 columns are read from disk and transferred through memory for every matching row, even though 17 columns are discarded by the application

Answer

The extra columns cause the query to run slower because the database must sort more data

Answer

The database creates an index on all 20 columns, which increases write energy

Answer

The database must perform additional joins to retrieve the extra columns from related tables

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A query uses SELECT * to retrieve all 20 columns from a table, but the applicati...

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