What to do if the database loads at 100% every 30 minutes? How to solve the heavy analytical query problem?

If the database is loaded at 100% every 30 minutes, it is likely that a heavy analytical query or a batch of queries is running at that time. To address the issue, you can take the following steps:

1. Analyze the queries — use a profiler or logs to determine which specific query is causing the load.
2. Optimize the query — check indexes, rewrite the query, use aggregations, reduce the amount of data processed.
3. Use caching — if the data does not change often, cache the results of the heavy query.
4. Distribute the load — move analytical queries to a separate replicated server or use specialized analytical databases (e.g., ClickHouse, ElasticSearch).
5. Schedule execution — run heavy queries during off-peak hours or break them into parts.

Example of query optimization in PostgreSQL:

-- Add an index to speed up selection
CREATE INDEX idx_orders_created_at ON orders(created_at);

-- Use aggregate functions with filtering by index
SELECT customer_id, SUM(amount) FROM orders
WHERE created_at >= NOW() - INTERVAL '1 day'
GROUP BY customer_id;

Thus, identifying and optimizing heavy queries, as well as distributing the load, are key steps to solving the problem.