Multiple choice technology databases

A SELECT statement can be to perform these three functions: -Choose rows from a table -Choose columns from a table -Bring together data that is stored in different tables by creating a link between them. Which set of keywords describe these capabilities?

  1. difference,projection,join

  2. selection.projection,join

  3. selection,intersection,join

  4. intersection,projection,join

  5. difference,projection,product
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B Correct answer
Explanation

In relational algebra, the three core capabilities of SELECT are: selection (choosing rows based on criteria), projection (choosing specific columns), and join (combining data from multiple tables based on related columns).

AI explanation

In relational algebra terms, choosing rows from a table is selection, choosing columns is projection, and combining data from different tables via a common field is a join. These three terms map directly onto the WHERE-clause row filtering, column list, and multi-table query capabilities of a SQL SELECT statement, whereas 'difference' and 'intersection' are set operators unrelated to picking rows/columns.

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