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| tanszek:oktatas:techcomm:information_-_basics:sciences [2026/09/14 21:30] – knehez | tanszek:oktatas:techcomm:information_-_basics:sciences [2026/09/15 04:46] (current) – knehez |
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| - **Seeking Appropriate Conditions:** The task is to optimize the query by structuring it to minimize response time and resource usage. | - **Seeking Appropriate Conditions:** The task is to optimize the query by structuring it to minimize response time and resource usage. |
| - **There’s no single “perfect” solution** for optimizing the query, because different query structures can yield the same result, but with varying degrees of performance based on the specific context (e.g., hardware, data distribution, and load). | - **There’s no single “perfect” solution** for optimizing the query, because different query structures can yield the same result, but with varying degrees of performance based on the specific context (e.g., hardware, data distribution, and load). |
| - Additionally, the same query might perform differently on different database engines (e.g., MySQL vs. PostgreSQL), and therefore there can be an infinite number of ways to structure a query that achieves the same end result. | - Additionally, the same query might perform differently on different database engines (e.g., MySQL vs. PostgreSQL), and therefore __there can be an infinite number of ways to structure a query__ that achieves the same end result. |
| - **Reducing the Number of Conditions:**: The database administrator (DBA) or developer uses **heuristic methods** like: | - **Reducing the Number of Conditions:**: The database administrator (DBA) or developer uses **heuristic methods** like: |
| - Query profiling tools (e.g., EXPLAIN in SQL) to examine how different query structures perform. | - Query profiling tools (e.g., EXPLAIN in SQL) to examine how different query structures perform. |
