On 2018/05/18 6:14, David Rowley wrote: > On 18 May 2018 at 02:13, Tom Lane <t...@sss.pgh.pa.us> wrote: >> Maybe what you need is a redesign. This convention seems impossibly >> confusing and hence error-prone. What about using a separate bool to >> indicate which list the index refers to? > > While I agree that the coding is a bit unusual, I think it's also good > that we can get away without allocating yet another array nparts in > size. ExecSetupPartitionTupleRouting is already a huge bottleneck with > single-row INSERT into a partitioned table with a large number of > partitions. Allocating yet another array nparts in size will just slow > it down further.
I recall having considered the idea of adding an array of bools, but went with the negative-indexes-for-partitioned-tables idea anyway, which I remember was suggested by Robert back then [1]. I admit it's a bit confusing, but it's nice not have one more array allocation in that path as you say. > I have patches locally that I'll be submitting during the v12 cycle to > improve on this. Among other things, the patches go to lengths to not > allocate these arrays when we don't have to. That would be nice. Thanks, Amit [1] https://www.postgresql.org/message-id/CA%2BTgmobF2r%3Df-crrE-k7WM8iFpBKLz3dtBtEc%3DKmkudYViYcyQ%40mail.gmail.com
