PRIMARY KEY constraint is not persistent through server restarts

[nuno-faria]

Describe the bug
The PRIMARY KEY constraint is ignored when the server restarts, allowing multiples rows with the same key.

To Reproduce

• Create a table with primary key

  CREATE TABLE Test (k int PRIMARY KEY, v int);
  
  \d Test
    CREATE TABLE "sys"."test" (
        "k" INTEGER       NOT NULL,
        "v" INTEGER,
        CONSTRAINT "test_k_pkey" PRIMARY KEY ("k")
    );

• Check that the PRIMARY KEY constraint is respected:

  INSERT INTO Test VALUES(1, 1);
    1 affected row
  
  INSERT INTO Test VALUES(1, 1);
    INSERT INTO: PRIMARY KEY constraint 'test.test_k_pkey' violated

• Restart the server

• Check that the PRIMARY KEY constraint is ignored:

  \d Test
    CREATE TABLE "sys"."test" (
        "k" INTEGER       NOT NULL,
        "v" INTEGER,
        CONSTRAINT "test_k_pkey" PRIMARY KEY ("k") -- still here
    );
  
  INSERT INTO Test VALUES(1, 1);
    1 affected row
  INSERT INTO Test VALUES(1, 1);
    1 affected row
  INSERT INTO Test VALUES(1, 1);
    1 affected row
  
  SELECT * FROM Test;
    +------+------+
    | k    | v    |
    +======+======+
    |    1 |    1 |
    |    1 |    1 |
    |    1 |    1 |
    |    1 |    1 |
    +------+------+

Software versions

• MonetDB master branch (most recent commit)
• Ubuntu 20.04 LTS
• Self-installed and compiled

[yzchang]

I can reproduce this with Jan2022-SP1