On Tue, Apr 10, 2012 at 4:59 PM, Jeff Davis <pg...@j-davis.com> wrote:
> On Tue, 2012-04-10 at 16:07 -0400, Kenneth Tilton wrote: > > Suppose I have an RDF-style table (with columns for subject, > > predicate, various object types, and graph) and want to have dozens or > > even hundreds of trigger functions defined conditionally on the > > predicate, ie "when predicate = '<your predicate here>'". > > > > > > My guess is Postgres is quite efficient at determining which if any > > trigger functions to call, but I thought I'd ask. > > I recommend measuring the overhead with some bogus no-op triggers; my > guess is that it will be significant but maybe not too bad depending on > what the rest of the application is doing. > > What are you trying to accomplish with so many triggers? > We are simulating a graph DB in Postgres and would have one RDF-like table with columns as described above. If we want a trigger on what is conventionally a column for "color", with pseudo-RDF we would have: create trigger ... when predicate = 'color' Since the graph data model reduces *everything *into so many RDF "triples", almost every trigger function in the application would be "when predicate = X". well, let's see how many we really get before we panic. :) Thx for the input. -ken
