On 2017/06/20 20:37, Amit Kapila wrote: > On Tue, Jun 20, 2017 at 1:50 PM, Amit Langote > <langote_amit...@lab.ntt.co.jp> wrote: >> On 2017/06/19 23:31, Tom Lane wrote: >>> I'd suggest a rule like "if pd_lower is smaller than SizeOfPageHeaderData >>> then don't trust it, but assume all of the page is valid data". >> >> Actually, such a check is already in place in the tool, whose condition >> looks like: >> >> if (PageGetPageSize(header) == BLCKSZ && >> PageGetPageLayoutVersion(header) == PG_PAGE_LAYOUT_VERSION && >> (header->pd_flags & ~PD_VALID_FLAG_BITS) == 0 && >> header->pd_lower >= SizeOfPageHeaderData && >> header->pd_lower <= header->pd_upper && >> header->pd_upper <= header->pd_special && >> header->pd_special <= BLCKSZ && >> header->pd_special == MAXALIGN(header->pd_special) && ... >> >> which even GIN metapage passes, making it an eligible data page and hence >> for omitting the hole between pd_lower and pd_upper. >> > > Won't checking for GIN_META in header->pd_flags gives you what you want?
GIN_META flag is not written into pd_flags but GinPageOpaqueData.flags, which still requires including GIN's private header. Thanks, Amit -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
