How Can I Quickly Deduplicate a Massive MySQL Database?

Speedy De-duplication of Massive MySQL Databases: Unlocking Optimization

Battling with a bloated MySQL database riddled with duplicates? Not to worry, help is at hand. Uncover a swift solution to eliminate these unwanted repetitions and streamline your database.

Conventional methods, such as GROUP BY and SELECT DISTINCT, may stumble under the weight of colossal databases. But fear not, a more efficient path lies ahead.

Introducing a dynamic duo: ON DUPLICATE KEY and IFNULL() combine forces to create a lightning-fast de-duplication strategy. Here's how it works:

1. Construct a temporary table, tmp, mirroring the structure of your original table.
2. Add a unique constraint on (text1, text2) to tmp.
3. Populate tmp with data from your original table.
4. Deploy the ON DUPLICATE KEY UPDATE clause to update the text3 column with values from new records only if it's currently null.
5. Rename tmp to replace your original table.

This innovative approach harnesses indexing to dramatically accelerate performance. By avoiding costly sorting and filtering operations, execution time plummets. Embrace this optimization to restore order to your data and unleash the full potential of your MySQL database.

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