Alvaro Herrera <[email protected]> wrote: > On 2026-Mar-19, Antonin Houska wrote: > > > Alvaro Herrera <[email protected]> wrote: > > > > > So here's v43. Here, I've changed the CONCURRENTLY implementation to go > > > through table AM. This necessitated changing it to use tuples in slots > > > instead of HeapTuple. This is good because we can avoid repeated tuple > > > form/deform, which could get pretty expensive. Antonin's 0004 patch > > > here looks suspicious here though, because it deforms the tuple and > > > forms it again, which sounds unnecessary now. > > > > I suppose you mean > > v42-0004-Serialize-decoded-tuples-without-flattening.patch. This deforms the > > tuple to get the external attributes and to write them to file. The tuple > > the > > logical worker received from reorderbuffer.c cannot be passed to the backend > > executing REPACK because it may contain "external indirect" attributes, > > i.e. pointers to the worker's memory. > > No, that patch has been absorbed in what is now v43-0003. I meant > v43-0004 "Use BulkInsertState when copying data to the new heap.", > that's why I said "patch 0004 here". In this patch, we have > reform_tuple which deforms the tuple, sets to NULL any attribute that's > marked dropped, and then forms a new one. This is wasteful and should > probably be done elsewhere, while the tuple is still in slot > representation. In fact, I suspect it may not be necessary at all > anymore.
The idea to "reform" the tuple comes from VACUUM FULL / CLUSTER. I agree the "deform" and "form" steps are no longer needed when we use tuple slots. -- Antonin Houska Web: https://www.cybertec-postgresql.com
