Lukas Eder covers mapping functions:
ARRAYtypes are a part of the ISO/IEC 9075 SQL standard. The standard specifies how to:
- Construct arrays
- Nest data into arrays (e.g. by means of aggregation or subqueries)
- Unnest data from arrays into tables
But it is very unopinionated when it comes to function support. The ISO/IEC 9075-2:2023(E) 6.47
<array value expression>specifies concatenation of arrays, whereas the 6.48<array value function>section lists a not extremely usefulTRIM_ARRAYfunction, exclusively (using which you can remove the lastNelements of an array, something I have yet to encounter a use-case for)
There are a few database platforms that support the ARRAY type, as Lukas lays out.