The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/13/functions-array.html
Description:
For whom it may concern,
I'd like to propose an extension for `array_length` function description.
Currently, it does not cover the case of an empty array:
https://www.postgresql.org/docs/13/functions-array.html
Table 9.52. Array Functions. Row 5
The description reads as `Returns the length of the requested array
dimension.`
For me, an expected result for an empty array would be `0`, but it is
`NULL`.
Tested on `PostgreSQL 13.4` with query `SELECT
ARRAY_LENGTH(ARRAY[]::CHARACTER VARYING[],1);`
I believe, such case deserves to be mentioned in the description and/or in
examples.
With best regards,
Oleg Rekin