diff --git a/test_runner/regress/test_explain_with_lfc_stats.py b/test_runner/regress/test_explain_with_lfc_stats.py new file mode 100644 index 0000000000..5231dedcda --- /dev/null +++ b/test_runner/regress/test_explain_with_lfc_stats.py @@ -0,0 +1,84 @@ +from pathlib import Path + +from fixtures.log_helper import log +from fixtures.neon_fixtures import NeonEnv + + +def test_explain_with_lfc_stats(neon_simple_env: NeonEnv): + env = neon_simple_env + + cache_dir = Path(env.repo_dir) / "file_cache" + cache_dir.mkdir(exist_ok=True) + + branchname = "test_explain_with_lfc_stats" + env.neon_cli.create_branch(branchname, "empty") + log.info(f"Creating endopint with 1MB shared_buffers and 64 MB LFC for branch {branchname}") + endpoint = env.endpoints.create_start( + branchname, + config_lines=[ + "shared_buffers='1MB'", + f"neon.file_cache_path='{cache_dir}/file.cache'", + "neon.max_file_cache_size='128MB'", + "neon.file_cache_size_limit='64MB'", + ], + ) + + cur = endpoint.connect().cursor() + + log.info(f"preparing some data in {endpoint.connstr()}") + + ddl = """ +CREATE TABLE pgbench_accounts ( + aid bigint NOT NULL, + bid integer, + abalance integer, + filler character(84), + -- more web-app like columns + text_column_plain TEXT DEFAULT repeat('NeonIsCool', 5), + jsonb_column_extended JSONB DEFAULT ('{ "tell everyone": [' || repeat('{"Neon": "IsCool"},',9) || ' {"Neon": "IsCool"}]}')::jsonb +) +WITH (fillfactor='100'); +""" + + cur.execute(ddl) + cur.execute( + "insert into pgbench_accounts(aid,bid,abalance,filler) select aid, (aid - 1) / 100000 + 1, 0, '' from generate_series(1, 100000) as aid;" + ) + + log.info(f"warming up caches with sequential scan in {endpoint.connstr()}") + cur.execute("SELECT * FROM pgbench_accounts WHERE abalance > 0") + + log.info("running explain analyze without LFC values to verify they do not show up in the plan") + cur.execute("EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM pgbench_accounts WHERE abalance > 0") + rows = cur.fetchall() + plan = "\n".join(r[0] for r in rows) + log.debug(plan) + assert "Seq Scan on pgbench_accounts" in plan + assert "Buffers: shared hit" in plan + assert "File cache: hits=" not in plan + log.info("running explain analyze WITH LFC values to verify they do now show up") + cur.execute( + "EXPLAIN (ANALYZE, BUFFERS,FILECACHE) SELECT * FROM pgbench_accounts WHERE abalance > 0" + ) + rows = cur.fetchall() + plan = "\n".join(r[0] for r in rows) + log.debug(plan) + assert "Seq Scan on pgbench_accounts" in plan + assert "Buffers: shared hit" in plan + assert "File cache: hits=" in plan + log.info("running explain analyze WITH LFC values to verify json output") + cur.execute( + "EXPLAIN (ANALYZE, BUFFERS,FILECACHE, FORMAT JSON) SELECT * FROM pgbench_accounts WHERE abalance > 0" + ) + jsonplan = cur.fetchall()[0][0] + log.debug(jsonplan) + # Directly access the 'Plan' part of the first element of the JSON array + plan_details = jsonplan[0]["Plan"] + + # Extract "File Cache Hits" and "File Cache Misses" + file_cache_hits = plan_details.get("File Cache Hits") + file_cache_misses = plan_details.get("File Cache Misses") + + # Now you can assert the values + assert file_cache_hits >= 5000, f"Expected File Cache Hits to be > 5000, got {file_cache_hits}" + assert file_cache_misses == 0, f"Expected File Cache Misses to be 0, got {file_cache_misses}"