> While testing "Optimize tuple deformation”, I found a bug: > ``` > evantest=# create table t (a int not null, > evantest(# g int generated always as (a+1) virtual not null, > evantest(# b int not null); > CREATE TABLE > evantest=# insert into t (a, b) values (10, 20); > INSERT 0 1 > evantest=# select a, g, b from t; > a | g | b > ----+----+--- > 10 | 11 | 0 > (1 row) > ```
Nice catch! I can reproduce this bug on master. Some comments about the fix: I find that a virtual generated column is stored as a null in heap tuple, so I think we should stop setting 'attcacheoff' when we see a virtual generated column in TupleDescFinalize(), or we will set wrong 'attcacheoff' value. But it seems that we don't use these wrong value because we can only use 'attcacheoff' up until the first NULL. -- Regards, ChangAo Chen
