DioCrafts
185 lines
8.2 KiB
PL/PgSQL
185 lines
8.2 KiB
PL/PgSQL
\set ON_ERROR_STOP on
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\pset pager off
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\pset format unaligned
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\pset tuples_only on
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-- SUPERSEDED EXPLORATORY FIXTURE: the tied-timestamp distribution is useful as
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-- a stress shape, but PostgreSQL posting-list compression makes its index-size
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-- result non-representative. Use admin_user_order_index_representative.sql for
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-- decisions; this file is retained only as historical evidence.
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-- Three-way Pareto gate for the stable admin pagination order:
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-- A. no index;
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-- B. created_at only (smaller btree + incremental sort inside ties);
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-- C. created_at,id (fully ordered scan).
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-- One hundred rows share each timestamp to reproduce CURRENT_TIMESTAMP ties.
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BEGIN;
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CREATE TEMP TABLE perf_users_base (
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id uuid NOT NULL,
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username text,
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email text NOT NULL,
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role_text text NOT NULL,
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storage_quota_bytes bigint NOT NULL,
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storage_used_bytes bigint NOT NULL,
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created_at timestamptz NOT NULL,
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last_login_at timestamptz,
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active boolean NOT NULL,
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oidc_provider text,
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is_external boolean NOT NULL
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);
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INSERT INTO perf_users_base
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SELECT
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gen_random_uuid(),
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'user-' || n,
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'user-' || n || '@example.invalid',
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CASE WHEN n % 20 = 0 THEN 'admin' ELSE 'user' END,
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10737418240,
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n::bigint * 1048576,
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timestamptz '2026-01-01 00:00:00+00' + make_interval(secs => n / 100),
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timestamptz '2026-01-01 00:00:00+00' + make_interval(secs => n / 2),
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true,
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CASE WHEN n % 3 = 0 THEN 'keycloak' END,
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n % 7 = 0
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FROM generate_series(1, 500000) AS n;
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CREATE TEMP TABLE perf_users_timestamp (LIKE perf_users_base INCLUDING ALL);
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CREATE TEMP TABLE perf_users_compound (LIKE perf_users_base INCLUDING ALL);
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INSERT INTO perf_users_timestamp SELECT * FROM perf_users_base;
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INSERT INTO perf_users_compound SELECT * FROM perf_users_base;
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CREATE INDEX perf_users_timestamp_idx ON perf_users_timestamp (created_at DESC);
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CREATE INDEX perf_users_compound_idx ON perf_users_compound (created_at DESC, id DESC);
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ANALYZE perf_users_base;
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ANALYZE perf_users_timestamp;
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ANALYZE perf_users_compound;
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SELECT 'timestamp_index_bytes|' || pg_relation_size('perf_users_timestamp_idx');
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SELECT 'compound_index_bytes|' || pg_relation_size('perf_users_compound_idx');
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SELECT 'tied_timestamp_groups|' || COUNT(*)
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FROM (SELECT created_at FROM perf_users_base GROUP BY created_at HAVING COUNT(*) > 1) tied;
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SELECT 'all_orders_match|' || (
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ARRAY(SELECT id FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 200 OFFSET 49900)
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= ARRAY(SELECT id FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 200 OFFSET 49900)
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AND ARRAY(SELECT id FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 200 OFFSET 49900)
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= ARRAY(SELECT id FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 200 OFFSET 49900)
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);
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\o /dev/null
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\timing on
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\echo warmup_no_index_first
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SELECT * FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo warmup_timestamp_first
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SELECT * FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo warmup_compound_first
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SELECT * FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo warmup_no_index_deep
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SELECT * FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo warmup_timestamp_deep
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SELECT * FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo warmup_compound_deep
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SELECT * FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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-- Rotate execution order between samples.
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\echo no_index_first_1
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SELECT * FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo timestamp_first_1
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SELECT * FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo compound_first_1
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SELECT * FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo timestamp_deep_1
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SELECT * FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo compound_deep_1
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SELECT * FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo no_index_deep_1
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SELECT * FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo compound_first_2
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SELECT * FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo no_index_first_2
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SELECT * FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo timestamp_first_2
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SELECT * FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo no_index_deep_2
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SELECT * FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo timestamp_deep_2
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SELECT * FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo compound_deep_2
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SELECT * FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo timestamp_first_3
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SELECT * FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo compound_first_3
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SELECT * FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo no_index_first_3
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SELECT * FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo compound_deep_3
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SELECT * FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo no_index_deep_3
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SELECT * FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo timestamp_deep_3
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SELECT * FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo no_index_first_4
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SELECT * FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo compound_first_4
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SELECT * FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo timestamp_first_4
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SELECT * FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo timestamp_deep_4
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SELECT * FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo no_index_deep_4
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SELECT * FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo compound_deep_4
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SELECT * FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo compound_first_5
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SELECT * FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo timestamp_first_5
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SELECT * FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo no_index_first_5
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SELECT * FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 100;
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\echo no_index_deep_5
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SELECT * FROM perf_users_base ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo compound_deep_5
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SELECT * FROM perf_users_compound ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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\echo timestamp_deep_5
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SELECT * FROM perf_users_timestamp ORDER BY created_at DESC, id DESC LIMIT 100 OFFSET 50000;
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-- Quantify both index write taxes over identical 10k-row inserts.
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\echo no_index_insert_1
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INSERT INTO perf_users_base SELECT * FROM perf_users_base LIMIT 10000;
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\echo timestamp_insert_1
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INSERT INTO perf_users_timestamp SELECT * FROM perf_users_timestamp LIMIT 10000;
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\echo compound_insert_1
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INSERT INTO perf_users_compound SELECT * FROM perf_users_compound LIMIT 10000;
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\echo compound_insert_2
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INSERT INTO perf_users_compound SELECT * FROM perf_users_compound LIMIT 10000;
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\echo no_index_insert_2
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INSERT INTO perf_users_base SELECT * FROM perf_users_base LIMIT 10000;
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\echo timestamp_insert_2
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INSERT INTO perf_users_timestamp SELECT * FROM perf_users_timestamp LIMIT 10000;
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\echo timestamp_insert_3
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INSERT INTO perf_users_timestamp SELECT * FROM perf_users_timestamp LIMIT 10000;
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\echo compound_insert_3
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INSERT INTO perf_users_compound SELECT * FROM perf_users_compound LIMIT 10000;
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\echo no_index_insert_3
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INSERT INTO perf_users_base SELECT * FROM perf_users_base LIMIT 10000;
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\echo no_index_insert_4
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INSERT INTO perf_users_base SELECT * FROM perf_users_base LIMIT 10000;
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\echo timestamp_insert_4
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INSERT INTO perf_users_timestamp SELECT * FROM perf_users_timestamp LIMIT 10000;
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\echo compound_insert_4
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INSERT INTO perf_users_compound SELECT * FROM perf_users_compound LIMIT 10000;
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\echo compound_insert_5
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INSERT INTO perf_users_compound SELECT * FROM perf_users_compound LIMIT 10000;
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\echo timestamp_insert_5
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INSERT INTO perf_users_timestamp SELECT * FROM perf_users_timestamp LIMIT 10000;
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\echo no_index_insert_5
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INSERT INTO perf_users_base SELECT * FROM perf_users_base LIMIT 10000;
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\timing off
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\o
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ROLLBACK;
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