Re:Postgres 15 improves UNIQUE and NULL
by masklinn on Monday July 11, 2022 @06:20AM
(#32054291)
Their statement is not “in the general case” though, it’s specifically for postgres.
Postgres uses a fixed-size null bitmap and variable-size rows, so a NULL value takes one bit in the bitmap (and additional nullable columns may require a wider bitmap), but they are skipped in the row itself.
Postgres uses a fixed-size null bitmap and variable-size rows, so a NULL value takes one bit in the bitmap (and additional nullable columns may require a wider bitmap), but they are skipped in the row itself.