Optimize Queries with a Partial Index on Active Orders
Creating a Partial Index in PostgreSQL
Write a PostgreSQL query to create a partial index that only covers rows meeting a specific condition.
Solution:
-- Specify the action to create a partial index.
CREATE INDEX idx_orders_active
-- Define the target table and column for the index.
ON Orders(order_date)
-- Add a condition to limit the index to rows with active status.
WHERE status = 'active';
Explanation:
- Purpose of the Query:
- To index only a subset of rows (e.g., active orders), thereby saving space and improving performance for targeted queries.
- Key Components:
- WHERE status = 'active' : Limits the index to rows meeting the condition.
- idx_orders_active and ON Orders(order_date) : Define the index name and target column.
Notes:
- Partial indexes are ideal for large tables where only a portion of the data is frequently queried.
- They reduce index size and improve maintenance efficiency.
For more Practice: Solve these Related Problems:
- Write a PostgreSQL query to create a partial index on the "order_date" column for orders with status 'completed' in the "Orders" table.
- Write a PostgreSQL query to create a partial index on the "active" column in the "Users" table where active is true.
- Write a PostgreSQL query to create a partial index on the "price" column in the "Products" table where price is above 100.
- Write a PostgreSQL query to create a partial index on the "last_login" column in the "Customers" table for logins within the past 30 days.
Go to:
PREV : Reindexing a Table in PostgreSQL.
NEXT : Creating an Expression Index in PostgreSQL.
Have another way to solve this solution? Contribute your code (and comments) through Disqus.
What is the difficulty level of this exercise?
Test your Programming skills with w3resource's quiz.
