I have been evolving details for Direct TOAST design in https://wiki.postgresql.org/wiki/DirectTOAST
The top level goals are * 8-byte TOAST pointer - just (header:1, tag:1 and TID:6) * all other info moved from toast pointer to actual toast record(s), so heap rows are smaller and faster. * all extra fields are bytea with internal encoding (maybe will create full new types for these, or maybe just introspection functions are enough) the reasons for this are - PostgresSQL arrays add 20 byte overhead - bytea gives other freedoms in encoding for minimal space usage No solution yet for va_toastrelid , but hope is - to use some kind of mapping and find one or two free bits somewhere (tid has one free), - or add a 12-byte toast pointer just for this. - or to make sure that CLUSTER and VACUUM FULL can be done without needing va_toastrelid. I assume it is there for clustering the TOAST which will be not possible separately from the main heap with direct toast tid pointers anyway. Please take a look and poke holes in it ! On Sun, Jul 20, 2025 at 10:28 AM Nikhil Kumar Veldanda <veldanda.nikhilkuma...@gmail.com> wrote: > > Hi, > > > v26-0014-Design-to-extend-the-varattrib_4b-and-toast-poin.patch: > > Design proposal covering varattrib_4b, TOAST pointer layouts, and > > related macro updates. > > v26-0015-Implement-Zstd-compression-no-dictionary-support.patch: Plain > > ZSTD (non dict) support and few basic tests. > > Sending v27 patch with a small update over v26 patch. > > v27-0014-Design-to-extend-the-varattrib_4b-and-toast-poin.patch: > Design proposal covering varattrib_4b, TOAST pointer layouts, and > related macro updates. > v27-0015-Implement-Zstd-compression-no-dictionary-support.patch: Plain > ZSTD (non dict) support and few basic tests. > > > -- > > Nikhil Veldanda > > -- > Nikhil Veldanda
