How to Speed Up Slow SQL Queries: Choosing Driver Tables and Join Strategies

This article analyzes a slow SQL query by examining driver tables, execution plans, and table row counts, then demonstrates three optimization approaches—setting a small table as driver, setting a large table as driver, and switching to hash joins—showing their impact on execution time and providing practical guidelines for selecting the best strategy.

Driver TableHash JoinOceanBase

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How to Speed Up Slow SQL Queries: Choosing Driver Tables and Join Strategies

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Nov 15, 2016 · Databases

How I Cut a 4‑Minute Oracle Query to 3.5 Seconds: A Step‑by‑Step SQL Optimization Tale

After a typhoon delayed work, the author tackled a 347‑line Oracle SQL that took over four minutes to return results, dissected its massive subqueries and views, applied three rounds of restructuring with WITH clauses and driver‑table tactics, and ultimately reduced the total runtime to just 3.5 seconds while dramatically speeding up deep data extraction.

Driver TableOracleSQL

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How I Cut a 4‑Minute Oracle Query to 3.5 Seconds: A Step‑by‑Step SQL Optimization Tale