1) Time: 53,699 ms
Time: 60,146 ms
Time: 60,594 ms

Avg:  58,1 ms

2) Time: 1020,832 ms
Time: 1061,554 ms (00:01,062)
Time: 1148,029 ms (00:01,148)

Avg: 1076 ms

3)  Time: 20,972 ms
regression=# \gexec
ALTER TABLE
Time: 12,601 ms
Time: 3,106 ms
sum = 36,67

Time: 22,087 ms
regression=# \gexec
ALTER TABLE
Time: 40,768 ms
Time: 3,154 ms
sum = 66,01

Time: 13,865 ms
regression=# \gexec
ALTER TABLE
Time: 34,619 ms
Time: 3,063 ms
sum = 51,55

Avg: 51,4 ms

4) Time: 25,518 ms
ime: 35,746 ms
Time: 39,232 ms

Avg: 33,4 ms