v8-0001-benchmark.patch

From b9dd617269419b8c8d9e7df9afd690a2035ef0c9 Mon Sep 17 00:00:00 2001
From: Alexandre Felipe <o.alexandre.felipe@gmail.com>
Date: Thu, 2 Apr 2026 22:42:37 +0100
Subject: [PATCH 1/6] benchmark

SQL script to measure planning time with varying numbers of indices.
Tests with 0, 5, 10, 20, and 50 additional indices.
---
 bench_slope_planning.sql | 138 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 138 insertions(+)
 create mode 100644 bench_slope_planning.sql

diff --git a/bench_slope_planning.sql b/bench_slope_planning.sql
new file mode 100644
index 00000000000..0b3d12cc82f
--- /dev/null
+++ b/bench_slope_planning.sql
@@ -0,0 +1,138 @@
+--
+-- SLOPE Planning Time Benchmark (Single Connection)
+--
+-- Measures planning time for queries that benefit from SLOPE optimization.
+-- Tests with varying numbers of indices to see scaling behavior.
+-- Uses clock_timestamp() to measure time spent in EXPLAIN (without ANALYZE).
+--
+
+-- Force index usage
+SET enable_seqscan = off;
+SET enable_bitmapscan = off;
+SET enable_hashagg = off;
+
+-- Create results table
+DROP TABLE IF EXISTS bench_results;
+CREATE TABLE bench_results (
+    id serial PRIMARY KEY,
+    num_indices int NOT NULL,
+    planning_time_us numeric NOT NULL
+);
+
+-- Function to create test table with N indices
+CREATE OR REPLACE FUNCTION setup_bench_table(p_num_indices int) RETURNS void AS $$
+DECLARE
+    v_i int;
+BEGIN
+    DROP TABLE IF EXISTS bench_slope CASCADE;
+    
+    CREATE TABLE bench_slope (
+        id serial PRIMARY KEY,
+        ts timestamp NOT NULL,
+        v_int4 int4 NOT NULL,
+        v_float8 float8 NOT NULL
+    );
+    
+    -- Always create index on ts (the one we query)
+    CREATE INDEX ON bench_slope (ts);
+    
+    -- Create additional indices to stress the planner
+    FOR v_i IN 1..p_num_indices LOOP
+        EXECUTE format('CREATE INDEX ON bench_slope ((v_int4 + %s))', v_i);
+    END LOOP;
+    
+    INSERT INTO bench_slope (ts, v_int4, v_float8)
+    SELECT
+        '2020-01-01'::timestamp + (i || ' hours')::interval,
+        i,
+        i::float8
+    FROM generate_series(1, 1000) i;
+    
+    ANALYZE bench_slope;
+END;
+$$ LANGUAGE plpgsql;
+
+-- Benchmark function for a specific number of indices
+CREATE OR REPLACE FUNCTION bench_slope_planning_n(
+    p_num_indices int,
+    p_iterations int,
+    p_warmup int
+) RETURNS void AS $$
+DECLARE
+    v_start timestamp;
+    v_end timestamp;
+    v_elapsed_us numeric;
+    v_i int;
+    v_plan text;
+BEGIN
+    -- Setup table
+    PERFORM setup_bench_table(p_num_indices);
+
+    -- Warmup phase
+    FOR v_i IN 1..p_warmup LOOP
+        FOR v_plan IN EXPLAIN SELECT date_trunc('month', ts), count(*) FROM bench_slope GROUP BY 1 LOOP
+        END LOOP;
+    END LOOP;
+
+    -- Benchmark phase
+    FOR v_i IN 1..p_iterations LOOP
+        v_start := clock_timestamp();
+        FOR v_plan IN EXPLAIN SELECT date_trunc('month', ts), count(*) FROM bench_slope GROUP BY 1 LOOP
+        END LOOP;
+        v_end := clock_timestamp();
+        v_elapsed_us := extract(epoch from (v_end - v_start)) * 1000000;
+        INSERT INTO bench_results (num_indices, planning_time_us) 
+        VALUES (p_num_indices, v_elapsed_us);
+    END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+
+-- Run the benchmark
+\echo '========================================================================'
+\echo 'SLOPE Planning Time Benchmark (Single Connection, Varying Indices)'
+\echo '========================================================================'
+\echo ''
+
+TRUNCATE bench_results;
+
+\echo 'Testing with 0 additional indices...'
+SELECT bench_slope_planning_n(0, 5000, 50);
+
+\echo 'Testing with 5 additional indices...'
+SELECT bench_slope_planning_n(5, 5000, 50);
+
+\echo 'Testing with 10 additional indices...'
+SELECT bench_slope_planning_n(10, 5000, 50);
+
+\echo 'Testing with 20 additional indices...'
+SELECT bench_slope_planning_n(20, 5000, 50);
+
+\echo 'Testing with 50 additional indices...'
+SELECT bench_slope_planning_n(50, 5000, 50);
+
+-- Results by number of indices
+\echo ''
+\echo 'Results by Number of Indices:'
+\echo ''
+
+SELECT
+    num_indices as "Indices",
+    count(*) as "N",
+    round(avg(planning_time_us)::numeric, 1) as "Mean (µs)",
+    round((percentile_cont(0.5) WITHIN GROUP (ORDER BY planning_time_us))::numeric, 1) as "Median (µs)",
+    round(stddev(planning_time_us)::numeric, 1) as "StdDev (µs)",
+    round((percentile_cont(0.05) WITHIN GROUP (ORDER BY planning_time_us))::numeric, 1) as "P5 (µs)",
+    round((percentile_cont(0.95) WITHIN GROUP (ORDER BY planning_time_us))::numeric, 1) as "P95 (µs)"
+FROM bench_results
+GROUP BY num_indices
+ORDER BY num_indices;
+
+-- Cleanup
+DROP FUNCTION bench_slope_planning_n(int, int, int);
+DROP FUNCTION setup_bench_table(int);
+DROP TABLE bench_results;
+DROP TABLE IF EXISTS bench_slope CASCADE;
+
+RESET enable_seqscan;
+RESET enable_bitmapscan;
+RESET enable_hashagg;
-- 
2.53.0