sql - MySQL how do i delete duplicate rows from very large table? -


I should know the most effective way to remove duplicated rows from a large table, (1 billion in this table More lines) I have to know a very efficient way of doing this, because I can take a few days if I execute ineffective queries.

I need to delete all the duplicate URLs in the search table,

Delete the search from the URL (URL from the search URL SELECT url) select url) X);

Depending on your index completely, do it in two steps: (1 ) Together with any other field, support your DBMS on the URL field create the highest-selection index, which can distinguish records with the same URL, such as the primary key or time stamp field; (2) To process a small fraction, write the procedural code (not just one query) if records at one time and results in these small batches, eg. PK mod 1000, or before the TLD portion, 3 letters of the URL harvesting.

This is the best way to get an estimated result, unless you are not sure that a simple query will be required during the long cycle of memory, log file location, etc. DB will not run out of the process. It removes

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