Add sqlsmith fuzzy test

.github/workflows/build_and_test.yaml

@@ -67,7 +67,7 @@ jobs:
           sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9
           sudo apt-get install -y build-essential libreadline-dev zlib1g-dev flex bison libxml2-dev libxslt-dev \
             libssl-dev libxml2-utils xsltproc pkg-config libc++-dev libc++abi-dev libglib2.0-dev libtinfo6 cmake \
-            libstdc++-12-dev ninja-build
+            libstdc++-12-dev ninja-build sqlsmith
           echo "${PWD}/postgres/inst/bin:$PATH'" > $GITHUB_PATH
 
       - name: ccache

test/pycheck/sqlsmith_fuzzy_test.py

@@ -0,0 +1,31 @@
+from .utils import Postgres, Cursor, run
+import pytest
+
+
+@pytest.mark.timeout(300)
+def test_fuzzy_pg_crashing(pg: Postgres, cur: Cursor):
+    cur.sql("CREATE DATABASE sqlsmith_test")
+    with pg.cur(dbname="sqlsmith_test") as sqlsmith_cur:
+        sqlsmith_cur.sql("CREATE EXTENSION pg_duckdb")
+        # create test tables with dummy data to allow sqlsmith to do more operations
+        sqlsmith_cur.sql("CREATE TABLE test_table (id INT, name TEXT)")
+        sqlsmith_cur.sql("CREATE TABLE test_table2 (id INT, name VARCHAR)")
+
+        sqlsmith_cur.sql(
+            "INSERT INTO test_table (SELECT num, 'name_' || num FROM generate_series(1, 100) as num)"
+        )
+        sqlsmith_cur.sql(
+            "INSERT INTO test_table2 (SELECT num, 'name_' || num FROM generate_series(10, 100) as num)"
+        )
+
+    # any crash caused by sqlsmith will be detected from logs on the teardown of pg fixture
+    run(
+        [
+            "/usr/bin/sqlsmith",
+            f"--target=host={pg.host} port={pg.port} user={pg.default_user} dbname=sqlsmith_test",
+            "--max-queries=1500",
+        ],
+        check=True,
+    )
+
+    cur.sql("DROP DATABASE sqlsmith_test")