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5bd8e2363a
This will help to keep us from using deprecated Python features going forward. Signed-off-by: Tristan Partin <tristan@neon.tech>
85 lines
3.1 KiB
Python
85 lines
3.1 KiB
Python
from __future__ import annotations
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from pathlib import Path
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from fixtures.log_helper import log
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from fixtures.neon_fixtures import NeonEnv
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def test_explain_with_lfc_stats(neon_simple_env: NeonEnv):
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env = neon_simple_env
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cache_dir = Path(env.repo_dir) / "file_cache"
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cache_dir.mkdir(exist_ok=True)
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log.info("Creating endpoint with 1MB shared_buffers and 64 MB LFC")
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endpoint = env.endpoints.create_start(
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"main",
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config_lines=[
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"shared_buffers='1MB'",
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f"neon.file_cache_path='{cache_dir}/file.cache'",
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"neon.max_file_cache_size='128MB'",
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"neon.file_cache_size_limit='64MB'",
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],
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)
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cur = endpoint.connect().cursor()
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log.info(f"preparing some data in {endpoint.connstr()}")
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ddl = """
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CREATE TABLE pgbench_accounts (
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aid bigint NOT NULL,
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bid integer,
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abalance integer,
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filler character(84),
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-- more web-app like columns
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text_column_plain TEXT DEFAULT repeat('NeonIsCool', 5),
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jsonb_column_extended JSONB DEFAULT ('{ "tell everyone": [' || repeat('{"Neon": "IsCool"},',9) || ' {"Neon": "IsCool"}]}')::jsonb
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)
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WITH (fillfactor='100');
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"""
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cur.execute(ddl)
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cur.execute(
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"insert into pgbench_accounts(aid,bid,abalance,filler) select aid, (aid - 1) / 100000 + 1, 0, '' from generate_series(1, 100000) as aid;"
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)
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log.info(f"warming up caches with sequential scan in {endpoint.connstr()}")
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cur.execute("SELECT * FROM pgbench_accounts WHERE abalance > 0")
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log.info("running explain analyze without LFC values to verify they do not show up in the plan")
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cur.execute("EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM pgbench_accounts WHERE abalance > 0")
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rows = cur.fetchall()
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plan = "\n".join(r[0] for r in rows)
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log.debug(plan)
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assert "Seq Scan on pgbench_accounts" in plan
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assert "Buffers: shared hit" in plan
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assert "File cache: hits=" not in plan
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log.info("running explain analyze WITH LFC values to verify they do now show up")
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cur.execute(
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"EXPLAIN (ANALYZE, BUFFERS,FILECACHE) SELECT * FROM pgbench_accounts WHERE abalance > 0"
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)
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rows = cur.fetchall()
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plan = "\n".join(r[0] for r in rows)
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log.debug(plan)
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assert "Seq Scan on pgbench_accounts" in plan
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assert "Buffers: shared hit" in plan
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assert "File cache: hits=" in plan
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log.info("running explain analyze WITH LFC values to verify json output")
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cur.execute(
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"EXPLAIN (ANALYZE, BUFFERS,FILECACHE, FORMAT JSON) SELECT * FROM pgbench_accounts WHERE abalance > 0"
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)
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jsonplan = cur.fetchall()[0][0]
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log.debug(jsonplan)
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# Directly access the 'Plan' part of the first element of the JSON array
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plan_details = jsonplan[0]["Plan"]
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# Extract "File Cache Hits" and "File Cache Misses"
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file_cache_hits = plan_details.get("File Cache Hits")
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file_cache_misses = plan_details.get("File Cache Misses")
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# Now you can assert the values
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assert file_cache_hits >= 5000, f"Expected File Cache Hits to be > 5000, got {file_cache_hits}"
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assert file_cache_misses == 0, f"Expected File Cache Misses to be 0, got {file_cache_misses}"
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