Hi,
thanks for your help which already resolved the issue for me. I worked through
your replies and it is indeed a startup delay for the first call to a plv8
function in a session. I pasted the query plans below for comparison.
```
explain analyze select normalizeunidiff('')
On 25 March 2018 at 18:00, Laurenz Albe wrote:
> Peter wrote:
>> Over all, VOLATILE performs better than STABLE.
>
> The reason is that the subquery with the VOLATILE function can be
> flattened; see the EXPLAIN (VERBOSE) output.
>
> There is not guarantee that less volatility means better perform
