Hi I'm currently working on a project where we need to build a global cache table containing all values of certain types found in any of the other tables. Currently, a seperate insert, update and delete (plpgsql) trigger function exists for each table in the database which is auto-generated by a (plpgsql) function which queries the system catalogs to find all fields with a certain type, and then generates the appropriate plpgsql function using EXECUTE '...'.
I'd like to replace this function-generating function by a generic trigger function that works for all tables. Due to the lack of any way to inspect the *structure* of a record type, however, I'd have to use a C language function for that, which induces quite some maintenance headaches (especially if deployed on windows). I'm therefore thinking about implementing the following generate-purpose inspection functions for row types record_length(record) returns smallint Returns the number of fields in the given record. record_names(record) returns name[] Returns the names of the record's fields. Array will contain NULLs if one or more fields are unnamed. record_types(record) returns regtype[]; Returns the OIDs of the record's types. Array won't contain NULLs record_value(record, name, anyelement) returns anyelement Returns the value of a certain (named) field. The type of the third argument defines the return type (its value is ignored). The field's value is cast to that type if possible, otherwise an error is raised. record_value(record, smallint, anyelement) returns anyelement Returns the value of the field at the given position. record_values(record, regtype, anyelement) returns anyarray Returns an array of all values of all fields with the given type or whose type is a domain over the given type. No casting is done. Any comment/critique is appreciated. Would anyone else find those functions useful? best regards, Florian Pflug
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