Optimize Employee ID Searches with a Hash Index

Hash Index on employee_id in Employees

Write a PostgreSQL query to create a hash index on the "employee_id" column in the Employees table.

Solution:

-- Create a hash index on the "employee_id" column.
CREATE INDEX idx_employees_id_hash ON Employees USING hash (employee_id);

Explanation:

• Purpose of the Query:
• To speed up exact-match searches on the "employee_id" column using a hash index.
• Demonstrates applying a hash index to numeric data for quick lookups.
• Key Components:
• USING hash sets the index type to hash.
• (employee_id) specifies the target column for the index.
• Real-World Application:
• Useful in scenarios where employee records are frequently retrieved by their unique IDs.

Notes:

• Hash indexes offer fast retrieval for equality comparisons but do not support ordering or range queries.
• Ensure that the workload benefits from the characteristics of hash indexing.

For more Practice: Solve these Related Problems:

• Write a PostgreSQL query to create a hash index on the "employee_id" column in the "Employees" table.
• Write a PostgreSQL query to create a hash index on the "order_id" column in the "Orders" table.
• Write a PostgreSQL query to create a hash index on the "product_id" column in the "OrderDetails" table.
• Write a PostgreSQL query to create a hash index on the "transaction_id" column in the "Transactions" table.

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• Hands-on PostgreSQL Indexing Techniques and Exercises Home. ↩
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