On 20/08/2018 12:32, Peter Eisentraut wrote: > On 18/08/2018 23:05, Tom Lane wrote: >> Possibly we need to be more careful than we are now about whether >> there's padding at the end of the fixed-size fields ... but just >> ripping out the code that attempts to deal with that is hardly >> an improvement. > > I don't think the tuple packing issue has to do with the tuple > descriptor code. The tuple descriptors already use allocations of size > sizeof(FormData_pg_attribute) (CreateTemplateTupleDesc), just the memcpy > and memset calls use (potentially) less. That might have saved a few > bytes for omitting the varlena fields, but I don't think it affects > alignment correctness. If we, say, added a trailing char field now, the > only thing this code
[oops] ... the only thing the current code would accomplish is not copying the last three padding bytes, which might even be slower than copying all four. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
