Reading this post, the author references a "non-volatile" expression, after researching a bit, I'm still not sure what it is. What is meant by a non-volatile expression in Postgresql?
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1A trip to the docco might be helpful.– VéraceDec 16, 2021 at 8:16
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1 Answer
"Immutable" expressions resolve to the same value always. Like 2 + 3.
"Stable" expressions resolve to the same value within a single table scan. Like: now().
"Volatile" expressions can resolve to a different value for each evaluation. Like: clock_timestamp().
"Non-volatile" would be in one of the first two categories.
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answered Dec 16, 2021 at 10:53
