hash

Quickly Testing A Refactored SQL Query for Equivalence

SQL /

A common problem I have worked on in my career has been to troubleshoot and improve slow, complex SQL queries. Usually these are part of codebases with few or no tests. If there are tests, they usually are testing some other part of the code and assume that the query is correct. It is rare to see tests that prove the columns being selected are […]

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Getting a quick hash of a query in PostgreSQL

SQL /

I’ve been doing a lot of tweaking of SQL queries as of late, trying to squeeze some performance out of a query by adding indexes, optimizing joins, and some other operations. To do a quick check to ensure that the queries return the same results, I’ve been hashing the results to see if I get an identical hash back. This solution was adapted from https://stackoverflow.com/a/13948327/206480.

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