(1) Missing contains(Object) function. Without this function, any ArrayList function like retainAll(...) did not work properly: the research in the collection was made with a bad key. KeyExtractor was not used.
(2) Result of a research (function get(...)) must return a copy of the result, since the result is an ArrayList, value of the HashMap used for research. If a copy is not returned, any modification (and particularly remove(...)) can be made on the value of the index (HashMap) used for the research.

TAP: Test better the JDBC connection URL: several syntaxes are possible. Here, the following syntax did not work before this correction: jdbc:postgresql:database (only if it is a local database). Only jdbc:postgresql://host/database and jdbc:postgresql://host:port/database worked!
TODO Parsing of JDBC connection URL should rather be checked again!

ADQL: Fix ArrayIndexOutOfBoundsException while initializing a DefaultUDF (User Defined Function) object with several parameters.