Oedipus found the sphinx near Thebes and the monster asked: "what is the thing that cannot be seen but can be called by name to change it?" Oedipus replied "it's RDB$GENERATORS" and the sphinx committed suicide.
Now if we replace the sphinx by a wolf, the wolf at Massachusetts asks: "in the release build I do CREATE GENERATOR RDB$GENERATORS; then how do I use it?" Nobody can answer. We are doomed. The system ties this name to the zeroth, invisible generator. It's hardcoded and the new generator that unwittingly stole the name is ignored. Using gen_id on that name will alter silently the sys gen, not the user gen. Only the debug build stops this creation with an assertion. To the dismay of Sean, I continue saying that while we don't declare "name independence" and continue relying on RDB$ for some decisions, it's better to forbit the RDB$ prefix for user objects. See, for example: SQL> create domain rdb$cats int; SQL> create table rdb$cats(rdb$cats rdb$cats); SQL> drop table rdb$cats; SQL> commit; <--- just to be sure SQL> show domains; There are no domains in this database (Now it's clear the explicit domain was wiped out just for using the wrong prefix.) I've seen other cases, it seems that they're stored in the tracker. Implicit objects could have a special sysflag value, but this is not a change that takes three minutes and can upset third party tools. Other things we should protect... by name for now, until we have more sysflags: SQL> show domain rdb$linger; RDB$LINGER INTEGER Nullable SQL> alter domain rdb$linger type bigint; SQL> show domain rdb$linger; RDB$LINGER BIGINT Nullable I should not be able to spoil a sys domain. I can't go back because the system protects the data integrity: SQL> alter domain rdb$linger type int; Statement failed, SQLSTATE = 42000 unsuccessful metadata update -ALTER DOMAIN RDB$LINGER failed -Cannot change datatype for RDB$LINGER. Conversion from base type BIGINT to INTEGER is not supported. C. --- Claudio Valderrama C. Consultant, SW developer. ------------------------------------------------------------------------------ Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
