Previewing a row-oriented table
When working with new tables, it is common to SELECT * to preview the data. However, selecting all the rows from a large table using row-oriented storage is resource intensive and slow. A quick optimization trick is to limit the number of rows returned.
You will be working with air quality data from the United States. This data lives in a Postgres database using row-oriented storage. Familiarize yourself with daily_aqi by previewing the data. First, select all records. Then limit the results to improve speed.
Use the EXPLAIN command to quantify the effect of limiting the rows.
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Improving Query Performance in PostgreSQL
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SELECT *
FROM daily_aqi;