On Mon, Dec 23, 2024 at 8:26 AM Tom Lane <t...@sss.pgh.pa.us> wrote:
> Michel Pelletier <pelletier.mic...@gmail.com> writes: > > ... > > I agree it makes sense to have more use cases before making deeper > > changes. I only work with expanded forms, but need to call wait() to > > pre-expand the object to avoid multiple expansions in functions that can > > take the same object in multiple parameters. > > Hmm. I agree that the wait() call is a bit ugly, but there are at > least two things that seem worth looking into before we go so far > as inventing type-support infrastructure: > 2. If the problem is primarily with passing the same object to > multiple parameters of a function, couldn't you detect and optimize > that within the function? It would be messier than just blindly > applying DatumGetWhatever() to each parameter position; but with a > bit of thought I bet you could create some support logic that would > hide most of the mess. > Ah that's a great idea, and it works beautifully! Now I can do an efficient triangle count without even needing a function, see below expand_matrix is only called once: postgres=# select reduce_scalar(mxm(graph, graph, mask=>graph, c=>graph)) / 6 as tcount from vlivejournals ; DEBUG: matrix_mxm DEBUG: DatumGetMatrix DEBUG: expand_matrix -- only called once! DEBUG: new_matrix DEBUG: DatumGetMatrixMaybeA DEBUG: DatumGetMatrixMaybeAB DEBUG: DatumGetMatrixMaybeABC DEBUG: matrix_reduce_scalar DEBUG: DatumGetMatrix DEBUG: new_scalar DEBUG: scalar_div_int32 DEBUG: new_scalar DEBUG: scalar_out ┌─────────────────┐ │ tcount │ ├─────────────────┤ │ int32:177820130 │ └─────────────────┘ What a wonderful Christmas present to me, thank you Tom! That pretty much resolves my main issues. I'm still in an exploratory phase but I think this gets me pretty far. Is this something that has to wait for 18 to be released? Also do you need any further testing or code reviewing from me? -Michel
