Hi! I'd suggest creating an API that defines a general function set with variable input, and calling implementation defined on the input type?
On Sat, Jan 7, 2023 at 12:32 PM Esteban Zimanyi <esteban.zima...@ulb.be> wrote: > Dear all > > MobilityDB (https://github.com/MobilityDB/MobilityDB) defines at the C > level four template types: Set, Span, SpanSet, and Temporal. The type Set > is akin to PostgreSQL's ArrayType restricted to one dimension, but enforces > the constraint that sets do not have duplicates, the types Span and SpanSet > are akin to PostgreSQL's RangeType and MultirangeType but enforce the > constraints that span types are of fixed length and that empty spans and > infinite bounds are not allowed, and the typeTemporal is used to > manipulate time-varying values. > > These template types need to be instantiated at the SQL level with base > types (int, bigint, float, timestamptz, text, ...) and because of this, > MobilityDB needs to define numerous SQL functions that all call the same > function in C. Taking as example the Set type, we need to define, e.g., > > CREATE FUNCTION intset_eq(intset, intset) RETURNS bool AS > 'MODULE_PATHNAME', 'Set_eq' ... > CREATE FUNCTION bigintset_eq(bigintset, bigintset) RETURNS bool AS > 'MODULE_PATHNAME', 'Set_eq' ... > CREATE FUNCTION floatset_eq(floatset, floatset) RETURNS bool AS > 'MODULE_PATHNAME', 'Set_eq' ... > CREATE FUNCTION textset_eq(textset, textset) RETURNS bool AS > 'MODULE_PATHNAME', 'Set_eq' ... > ... > > CREATE FUNCTION intset_ne(intset, intset) RETURNS bool AS > 'MODULE_PATHNAME', 'Set_ne' ... > CREATE FUNCTION bigintset_ne(bigintset, bigintset) RETURNS bool AS > 'MODULE_PATHNAME', 'Set_ne' ... > CREATE FUNCTION floatset_ne(floatset, floatset) RETURNS bool AS > 'MODULE_PATHNAME', 'Set_ne' ... > CREATE FUNCTION textset_ne(textset, textset) RETURNS bool AS > 'MODULE_PATHNAME', 'Set_ne' ... > ... > > In the case of arrays, ranges, and multiranges, PostgreSQL avoids this > redundancy using pseudo-types such as anyarray, anyrange, anymultirange, ... > > Is there a possibility that we can also define pseudo types such as > anyset, anyspan, anyspanset, anytemporal, .... ? > > This will considerably reduce the number of SQL functions to define. > Currently, given the high number of functions in MobilityDB, creating the > extension takes a loooong time .... > > Regards > > Esteban > > -- Regards, Nikita Malakhov Postgres Professional https://postgrespro.ru/
