Tom Lane <t...@sss.pgh.pa.us> wrote: > "Kevin Grittner" <kevin.gritt...@wicourts.gov> writes: >> Tom Lane <t...@sss.pgh.pa.us> wrote: >>> No. See subtransactions. > >> Subtransactions are included in snapshots? > > Sure, see GetSnapshotData(). You could avoid it by setting > suboverflowed, but that comes at a nontrivial performance cost. Yeah, sorry for blurting like that before I checked. I was somewhat panicked that I'd missed something important for SSI, because my XidIsConcurrent check just uses xmin, xmax, and xip; I was afraid what I have would fall down in the face of subtransactions. But on review I found that I'd thought that through and (discussion in in the archives) I always wanted to associate the locks and conflicts with the top level transaction; so that was already identified before checking for overlap, and it was therefore more efficient to just check that. Sorry for the "senior moment". :-/ Perhaps a line or two of comments about that in the SSI patch would be a good idea. And maybe some tests involving subtransactions.... -Kevin
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