> How about adding a column to pg_am indicating "these indexes must always
> keep same tuple count as heap". This would be true for all current AMs,
> false for GIN.
Yes, it's simplest solution, but it doesn't check of index consistency.
Possible, we can count number of itempointers to heap tuple during build/insert,
and during bulkdelete we count number of deleted and leaved itempointers. So,
N[before bulkdelete] == N[after bulkdelete] + N[deleted]
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Teodor Sigaev E-mail: teodor(at)sigaev(dot)ru
WWW: http://www.sigaev.ru/