task Indexes · medium

A covering index for unit totals

Create an index that lets SQLite answer total units per stock code from the index alone (stock_code, then quantity). Then return stock_code and units (sum of quantity) for stock codes beginning with '2272'.

what to return

Columns

stock_codeunits in this order

Rows

9 rows · any order

Skill

Answer a query from an index alone. Refresher: Indexes: observe a real access path →

expected result

Your query should return exactly these columns and values. Run it and compare.

data you can query

Retail dataset: the first 6 rows of each table. Under each column name: the kind of value it holds, and which table it links to. Your queries run on all rows.