慢 SQL，试图了解发生了什么
Slow SQL, trying to understand what is going on
我有这个 SQL 在生产服务器上开始 运行 非常慢 ( >20s )。当我 运行 它在本地笔记本电脑上的同一个数据库上时，它 运行s 低于 1s。
我知道 SQL 不是最优的，但我尝试 运行 EXPLAIN 但我不太明白结果。
SELECT ST.id,
ST.lot_id,
ST.warehouse_location_id,
WL.name,
P.id AS product_id,
P.sku,
P.code,
P.NAME AS product_name,
P.has_serial,
Sum(ST.quantity) AS qty,
Group_concat(ST.id) AS stock_transaction_ids
FROM stock_transactions ST LEFT JOIN products P
ON (P.id = ST.product_id)
LEFT JOIN warehouse_locations WL
ON (WL.id = ST.warehouse_location_id)
LEFT JOIN
(
SELECT stock_transaction_id,
Group_concat(serial_id) AS serials
FROM stock_transactions_serials
GROUP BY stock_transaction_id ) STS
ON STS.stock_transaction_id = ST.id
WHERE (
ST.document_type = "Goods transfer" AND
ST.document_id IN (806, 807, 808, 809, 810, 811, 812, 824, 827, 831, 835, 838, 839, 841, 868, 869, 870, 871, 872, 873, 874, 875, 876, 877, 878, 879, 880, 881, 882, 883, 884, 885, 886, 887, 888, 889, 890, 944, 945, 946, 954, 955, 956, 957, 961, 965, 966, 967, 2240, 2241, 2242, 2243, 2244, 2245, 2246, 2247, 2248, 2249, 2250, 2251, 2252, 2253, 2254, 2255, 2256, 2257, 2258, 2259, 2260, 2261, 2262, 2263, 2264, 2265, 2266, 2267, 2268, 2269, 2270, 2271, 2272, 2273, 2274, 2275, 2276, 2277, 2278, 2279, 2280, 2281, 2282, 2283, 2284, 2285, 2286, 2287, 2288, 2289, 2290, 2291, 2292, 2293, 2294, 2295, 2296, 2297, 2298, 2299, 2300, 2301, 2302, 2303, 2304, 2305, 2306, 2307, 2308, 2309, 2310, 2311, 2312, 2313, 2314, 2315, 2316, 2317, 2318, 2319, 2320, 2321, 2322, 2323, 2324, 2325, 2326, 2327, 2328, 2329, 2330, 2331, 2332, 2333, 2334, 2335, 2337, 2338, 2339, 2340, 2341, 2342, 2343, 2344, 2345, 2346, 2347, 2348, 2349, 2350, 2351, 2352, 2353, 2354, 2355, 2356, 2357, 2358, 2359, 2360, 2361, 2362, 2363, 2364, 2365, 2366, 2367, 2368, 2369, 2370, 2371, 2372, 2373, 2374, 2375, 2376, 2377, 2378, 2379, 2380, 2381, 2382, 2383, 2384, 2385, 2386, 2387, 2388, 2389, 2390, 2391, 2392, 2393, 2394, 2395, 2396, 2397, 2398, 2399, 2400, 2401, 2402, 2403, 2404, 2405, 2406, 2407, 2408, 2409, 2410, 2411, 2412, 2413, 2414, 2415, 2416, 2417, 2418, 2419, 2420, 2421, 2422, 2423, 2424, 2425, 2426, 2427, 2428, 2429, 2430, 2431, 2432, 2437, 2438, 2439, 2440, 2441, 2442, 2443, 2444, 2445, 2446, 2447, 2448, 2449, 2450, 2451, 2452, 2453, 2454, 2455, 2456, 2457, 2458, 2459, 2460, 2461, 2462, 2463, 2464, 2465, 2466, 2467, 2468, 2469, 2470, 2471, 2472, 2473, 2474, 2475, 2476, 2477, 2478, 2479, 2480, 2481, 2482, 2483, 2484, 2485, 2486, 2487, 2488, 2489, 2490, 2491, 2492, 2493, 2494, 2495, 2496, 2497, 2498, 2499, 2500, 2501, 2502, 2503, 2504, 2505, 2506, 2507, 2508, 2509, 2510, 2511, 2512, 2513, 2514, 2515, 2516, 2517, 2518, 2519, 2520, 2521, 2522, 2523, 2524, 2525, 2526, 2527, 2528, 2529, 2530, 2531, 2532, 2534, 2535, 2536, 2537, 2538, 2539, 2540, 2541, 2542, 2543, 2544, 2545, 2546, 2547, 2548, 2549, 2550, 2551, 2552, 2553, 2554, 2555, 2556, 2557, 2558, 2559, 2560, 2561, 2562, 2563, 2564, 2565, 2566, 2567, 2568, 2569, 2570, 2571, 2572, 2573, 2574, 2575, 2576, 2577, 2578, 2579, 2580, 2581, 2583, 2584, 2585, 2586, 2587, 2588, 2589, 2590, 2591, 2592, 2593, 2594, 2595, 2596, 2597, 2598, 2599, 2600, 2601, 2602, 2603, 2604, 2605, 2606, 2607, 2608, 2609, 2610, 2611, 2612, 2613, 2614, 2615, 2616, 2617, 2618, 2619, 2620, 2621, 2622, 2623, 2624, 2625, 2626, 2627, 2628, 2629, 2630, 3707, 3708, 10194, 10244, 10246, 10247, 10248, 10249, 10426, 10428, 27602, 27603, 28587, 28588, 28589, 28590, 28591, 28592, 28593, 28594, 28595, 28596, 28597, 28598, 28599, 28600, 28601, 28602, 28603, 28604, 28605, 28606, 28607, 28608, 28609, 28610, 28611, 28612, 28613, 28614, 28615, 28616, 28617, 28618, 28619, 28620, 28621, 28622, 28623, 28624, 28625, 28626, 28627, 28628, 28629, 28630, 28631, 28632, 28633, 28634, 28635, 28636, 28637, 28638, 28639, 28640, 28641, 28642, 28643) )
GROUP BY ST.product_id,
ST.lot_id,
ST.warehouse_location_id
HAVING qty > 0
解释让我明白了：
有人可以帮助理解发生了什么吗？我会看看我是否也可以带着 SQL fiddle 回来。
你有
ON STS.stock_transaction_id = ST.id
WHERE (
ST.document_type = "Goods transfer" AND
ST.document_id IN (806, 807, 808, 809, 810, 811, 812, -- etc
如果这些值在 goods_transfer_items 中的一个名为 id 的字段中，那么这在功能上将完全相同：
ON STS.stock_transaction_id = ST.id
JOIN goods_transfer_items ON goods_transfer_items.id = ST.document_id
AND goods_transfer_items.work_order_number=12345'
AND ST.document_type = "Goods transfer"
这不仅要短得多，而且速度也会快得多，因为 SQL 服务器可以优化连接。
这在功能上与 NOT IN
相同
之前的回答如下
您应该采用此处列出的值
ST.document_id IN (806, 807, 808, 809, 810, 811, 812, 824, 827, 831, 835, 838, 839, 841, 868, 869, 870, 871, 872, 873, 874, 875, 876, 877, 878, 879, 880, 881, 882, 883, 884, 885, 886, 887, 888, 889, 890, 944, 945, 946, 954, 955, 956, 957, 961, 965, 966, 967, 2240, 2241, 2242, 2243, 2244, 2245, 2246, 2247, 2248, 2249, 2250, 2251, 2252, 2253, 2254, 2255, 2256, 2257, 2258, 2259, 2260, 2261, 2262, 2263, 2264, 2265, 2266, 2267, 2268, 2269, 2270, 2271, 2272, 2273, 2274, 2275, 2276, 2277, 2278, 2279, 2280, 2281, 2282, 2283, 2284, 2285, 2286, 2287, 2288, 2289, 2290, 2291, 2292, 2293, 2294, 2295, 2296, 2297, 2298, 2299, 2300, 2301, 2302, 2303, 2304, 2305, 2306, 2307, 2308, 2309, 2310, 2311, 2312, 2313, 2314, 2315, 2316, 2317, 2318, 2319, 2320, 2321, 2322, 2323, 2324, 2325, 2326, 2327, 2328, 2329, 2330, 2331, 2332, 2333, 2334, 2335, 2337, 2338, 2339, 2340, 2341, 2342, 2343, 2344, 2345, 2346, 2347, 2348, 2349, 2350, 2351, 2352, 2353, 2354, 2355, 2356, 2357, 2358, 2359, 2360, 2361, 2362, 2363, 2364, 2365, 2366, 2367, 2368, 2369, 2370, 2371, 2372, 2373, 2374, 2375, 2376, 2377, 2378, 2379, 2380, 2381, 2382, 2383, 2384, 2385, 2386, 2387, 2388, 2389, 2390, 2391, 2392, 2393, 2394, 2395, 2396, 2397, 2398, 2399, 2400, 2401, 2402, 2403, 2404, 2405, 2406, 2407, 2408, 2409, 2410, 2411, 2412, 2413, 2414, 2415, 2416, 2417, 2418, 2419, 2420, 2421, 2422, 2423, 2424, 2425, 2426, 2427, 2428, 2429, 2430, 2431, 2432, 2437, 2438, 2439, 2440, 2441, 2442, 2443, 2444, 2445, 2446, 2447, 2448, 2449, 2450, 2451, 2452, 2453, 2454, 2455, 2456, 2457, 2458, 2459, 2460, 2461, 2462, 2463, 2464, 2465, 2466, 2467, 2468, 2469, 2470, 2471, 2472, 2473, 2474, 2475, 2476, 2477, 2478, 2479, 2480, 2481, 2482, 2483, 2484, 2485, 2486, 2487, 2488, 2489, 2490, 2491, 2492, 2493, 2494, 2495, 2496, 2497, 2498, 2499, 2500, 2501, 2502, 2503, 2504, 2505, 2506, 2507, 2508, 2509, 2510, 2511, 2512, 2513, 2514, 2515, 2516, 2517, 2518, 2519, 2520, 2521, 2522, 2523, 2524, 2525, 2526, 2527, 2528, 2529, 2530, 2531, 2532, 2534, 2535, 2536, 2537, 2538, 2539, 2540, 2541, 2542, 2543, 2544, 2545, 2546, 2547, 2548, 2549, 2550, 2551, 2552, 2553, 2554, 2555, 2556, 2557, 2558, 2559, 2560, 2561, 2562, 2563, 2564, 2565, 2566, 2567, 2568, 2569, 2570, 2571, 2572, 2573, 2574, 2575, 2576, 2577, 2578, 2579, 2580, 2581, 2583, 2584, 2585, 2586, 2587, 2588, 2589, 2590, 2591, 2592, 2593, 2594, 2595, 2596, 2597, 2598, 2599, 2600, 2601, 2602, 2603, 2604, 2605, 2606, 2607, 2608, 2609, 2610, 2611, 2612, 2613, 2614, 2615, 2616, 2617, 2618, 2619, 2620, 2621, 2622, 2623, 2624, 2625, 2626, 2627, 2628, 2629, 2630, 3707, 3708, 10194, 10244, 10246, 10247, 10248, 10249, 10426, 10428, 27602, 27603, 28587, 28588, 28589, 28590, 28591, 28592, 28593, 28594, 28595, 28596, 28597, 28598, 28599, 28600, 28601, 28602, 28603, 28604, 28605, 28606, 28607, 28608, 28609, 28610, 28611, 28612, 28613, 28614, 28615, 28616, 28617, 28618, 28619, 28620, 28621, 28622, 28623, 28624, 28625, 28626, 28627, 28628, 28629, 28630, 28631, 28632, 28633, 28634, 28635, 28636, 28637, 28638, 28639, 28640, 28641, 28642, 28643) )
将它们放在 table 中，在其上创建一个索引，然后内部连接到它而不是使用 IN
看来问题出在你的派生 table:
(
SELECT stock_transaction_id,
Group_concat(serial_id) AS serials
FROM stock_transactions_serials
GROUP BY stock_transaction_id ) STS
ON STS.stock_transaction_id = ST.id
我看不到您在查询的其他任何地方使用 serials，所以我猜这对您没有太大帮助，但成本很高 - 左连接未使用加入时的索引。我建议将其重写为 stock_transaction_serials 上的连接，而不是派生的 table.
我有这个 SQL 在生产服务器上开始 运行 非常慢 ( >20s )。当我 运行 它在本地笔记本电脑上的同一个数据库上时，它 运行s 低于 1s。
我知道 SQL 不是最优的，但我尝试 运行 EXPLAIN 但我不太明白结果。
SELECT ST.id,
ST.lot_id,
ST.warehouse_location_id,
WL.name,
P.id AS product_id,
P.sku,
P.code,
P.NAME AS product_name,
P.has_serial,
Sum(ST.quantity) AS qty,
Group_concat(ST.id) AS stock_transaction_ids
FROM stock_transactions ST LEFT JOIN products P
ON (P.id = ST.product_id)
LEFT JOIN warehouse_locations WL
ON (WL.id = ST.warehouse_location_id)
LEFT JOIN
(
SELECT stock_transaction_id,
Group_concat(serial_id) AS serials
FROM stock_transactions_serials
GROUP BY stock_transaction_id ) STS
ON STS.stock_transaction_id = ST.id
WHERE (
ST.document_type = "Goods transfer" AND
ST.document_id IN (806, 807, 808, 809, 810, 811, 812, 824, 827, 831, 835, 838, 839, 841, 868, 869, 870, 871, 872, 873, 874, 875, 876, 877, 878, 879, 880, 881, 882, 883, 884, 885, 886, 887, 888, 889, 890, 944, 945, 946, 954, 955, 956, 957, 961, 965, 966, 967, 2240, 2241, 2242, 2243, 2244, 2245, 2246, 2247, 2248, 2249, 2250, 2251, 2252, 2253, 2254, 2255, 2256, 2257, 2258, 2259, 2260, 2261, 2262, 2263, 2264, 2265, 2266, 2267, 2268, 2269, 2270, 2271, 2272, 2273, 2274, 2275, 2276, 2277, 2278, 2279, 2280, 2281, 2282, 2283, 2284, 2285, 2286, 2287, 2288, 2289, 2290, 2291, 2292, 2293, 2294, 2295, 2296, 2297, 2298, 2299, 2300, 2301, 2302, 2303, 2304, 2305, 2306, 2307, 2308, 2309, 2310, 2311, 2312, 2313, 2314, 2315, 2316, 2317, 2318, 2319, 2320, 2321, 2322, 2323, 2324, 2325, 2326, 2327, 2328, 2329, 2330, 2331, 2332, 2333, 2334, 2335, 2337, 2338, 2339, 2340, 2341, 2342, 2343, 2344, 2345, 2346, 2347, 2348, 2349, 2350, 2351, 2352, 2353, 2354, 2355, 2356, 2357, 2358, 2359, 2360, 2361, 2362, 2363, 2364, 2365, 2366, 2367, 2368, 2369, 2370, 2371, 2372, 2373, 2374, 2375, 2376, 2377, 2378, 2379, 2380, 2381, 2382, 2383, 2384, 2385, 2386, 2387, 2388, 2389, 2390, 2391, 2392, 2393, 2394, 2395, 2396, 2397, 2398, 2399, 2400, 2401, 2402, 2403, 2404, 2405, 2406, 2407, 2408, 2409, 2410, 2411, 2412, 2413, 2414, 2415, 2416, 2417, 2418, 2419, 2420, 2421, 2422, 2423, 2424, 2425, 2426, 2427, 2428, 2429, 2430, 2431, 2432, 2437, 2438, 2439, 2440, 2441, 2442, 2443, 2444, 2445, 2446, 2447, 2448, 2449, 2450, 2451, 2452, 2453, 2454, 2455, 2456, 2457, 2458, 2459, 2460, 2461, 2462, 2463, 2464, 2465, 2466, 2467, 2468, 2469, 2470, 2471, 2472, 2473, 2474, 2475, 2476, 2477, 2478, 2479, 2480, 2481, 2482, 2483, 2484, 2485, 2486, 2487, 2488, 2489, 2490, 2491, 2492, 2493, 2494, 2495, 2496, 2497, 2498, 2499, 2500, 2501, 2502, 2503, 2504, 2505, 2506, 2507, 2508, 2509, 2510, 2511, 2512, 2513, 2514, 2515, 2516, 2517, 2518, 2519, 2520, 2521, 2522, 2523, 2524, 2525, 2526, 2527, 2528, 2529, 2530, 2531, 2532, 2534, 2535, 2536, 2537, 2538, 2539, 2540, 2541, 2542, 2543, 2544, 2545, 2546, 2547, 2548, 2549, 2550, 2551, 2552, 2553, 2554, 2555, 2556, 2557, 2558, 2559, 2560, 2561, 2562, 2563, 2564, 2565, 2566, 2567, 2568, 2569, 2570, 2571, 2572, 2573, 2574, 2575, 2576, 2577, 2578, 2579, 2580, 2581, 2583, 2584, 2585, 2586, 2587, 2588, 2589, 2590, 2591, 2592, 2593, 2594, 2595, 2596, 2597, 2598, 2599, 2600, 2601, 2602, 2603, 2604, 2605, 2606, 2607, 2608, 2609, 2610, 2611, 2612, 2613, 2614, 2615, 2616, 2617, 2618, 2619, 2620, 2621, 2622, 2623, 2624, 2625, 2626, 2627, 2628, 2629, 2630, 3707, 3708, 10194, 10244, 10246, 10247, 10248, 10249, 10426, 10428, 27602, 27603, 28587, 28588, 28589, 28590, 28591, 28592, 28593, 28594, 28595, 28596, 28597, 28598, 28599, 28600, 28601, 28602, 28603, 28604, 28605, 28606, 28607, 28608, 28609, 28610, 28611, 28612, 28613, 28614, 28615, 28616, 28617, 28618, 28619, 28620, 28621, 28622, 28623, 28624, 28625, 28626, 28627, 28628, 28629, 28630, 28631, 28632, 28633, 28634, 28635, 28636, 28637, 28638, 28639, 28640, 28641, 28642, 28643) )
GROUP BY ST.product_id,
ST.lot_id,
ST.warehouse_location_id
HAVING qty > 0
解释让我明白了：
有人可以帮助理解发生了什么吗？我会看看我是否也可以带着 SQL fiddle 回来。
你有
ON STS.stock_transaction_id = ST.id
WHERE (
ST.document_type = "Goods transfer" AND
ST.document_id IN (806, 807, 808, 809, 810, 811, 812, -- etc
如果这些值在 goods_transfer_items 中的一个名为 id 的字段中，那么这在功能上将完全相同：
ON STS.stock_transaction_id = ST.id
JOIN goods_transfer_items ON goods_transfer_items.id = ST.document_id
AND goods_transfer_items.work_order_number=12345'
AND ST.document_type = "Goods transfer"
这不仅要短得多，而且速度也会快得多，因为 SQL 服务器可以优化连接。
这在功能上与 NOT IN
相同之前的回答如下
您应该采用此处列出的值
ST.document_id IN (806, 807, 808, 809, 810, 811, 812, 824, 827, 831, 835, 838, 839, 841, 868, 869, 870, 871, 872, 873, 874, 875, 876, 877, 878, 879, 880, 881, 882, 883, 884, 885, 886, 887, 888, 889, 890, 944, 945, 946, 954, 955, 956, 957, 961, 965, 966, 967, 2240, 2241, 2242, 2243, 2244, 2245, 2246, 2247, 2248, 2249, 2250, 2251, 2252, 2253, 2254, 2255, 2256, 2257, 2258, 2259, 2260, 2261, 2262, 2263, 2264, 2265, 2266, 2267, 2268, 2269, 2270, 2271, 2272, 2273, 2274, 2275, 2276, 2277, 2278, 2279, 2280, 2281, 2282, 2283, 2284, 2285, 2286, 2287, 2288, 2289, 2290, 2291, 2292, 2293, 2294, 2295, 2296, 2297, 2298, 2299, 2300, 2301, 2302, 2303, 2304, 2305, 2306, 2307, 2308, 2309, 2310, 2311, 2312, 2313, 2314, 2315, 2316, 2317, 2318, 2319, 2320, 2321, 2322, 2323, 2324, 2325, 2326, 2327, 2328, 2329, 2330, 2331, 2332, 2333, 2334, 2335, 2337, 2338, 2339, 2340, 2341, 2342, 2343, 2344, 2345, 2346, 2347, 2348, 2349, 2350, 2351, 2352, 2353, 2354, 2355, 2356, 2357, 2358, 2359, 2360, 2361, 2362, 2363, 2364, 2365, 2366, 2367, 2368, 2369, 2370, 2371, 2372, 2373, 2374, 2375, 2376, 2377, 2378, 2379, 2380, 2381, 2382, 2383, 2384, 2385, 2386, 2387, 2388, 2389, 2390, 2391, 2392, 2393, 2394, 2395, 2396, 2397, 2398, 2399, 2400, 2401, 2402, 2403, 2404, 2405, 2406, 2407, 2408, 2409, 2410, 2411, 2412, 2413, 2414, 2415, 2416, 2417, 2418, 2419, 2420, 2421, 2422, 2423, 2424, 2425, 2426, 2427, 2428, 2429, 2430, 2431, 2432, 2437, 2438, 2439, 2440, 2441, 2442, 2443, 2444, 2445, 2446, 2447, 2448, 2449, 2450, 2451, 2452, 2453, 2454, 2455, 2456, 2457, 2458, 2459, 2460, 2461, 2462, 2463, 2464, 2465, 2466, 2467, 2468, 2469, 2470, 2471, 2472, 2473, 2474, 2475, 2476, 2477, 2478, 2479, 2480, 2481, 2482, 2483, 2484, 2485, 2486, 2487, 2488, 2489, 2490, 2491, 2492, 2493, 2494, 2495, 2496, 2497, 2498, 2499, 2500, 2501, 2502, 2503, 2504, 2505, 2506, 2507, 2508, 2509, 2510, 2511, 2512, 2513, 2514, 2515, 2516, 2517, 2518, 2519, 2520, 2521, 2522, 2523, 2524, 2525, 2526, 2527, 2528, 2529, 2530, 2531, 2532, 2534, 2535, 2536, 2537, 2538, 2539, 2540, 2541, 2542, 2543, 2544, 2545, 2546, 2547, 2548, 2549, 2550, 2551, 2552, 2553, 2554, 2555, 2556, 2557, 2558, 2559, 2560, 2561, 2562, 2563, 2564, 2565, 2566, 2567, 2568, 2569, 2570, 2571, 2572, 2573, 2574, 2575, 2576, 2577, 2578, 2579, 2580, 2581, 2583, 2584, 2585, 2586, 2587, 2588, 2589, 2590, 2591, 2592, 2593, 2594, 2595, 2596, 2597, 2598, 2599, 2600, 2601, 2602, 2603, 2604, 2605, 2606, 2607, 2608, 2609, 2610, 2611, 2612, 2613, 2614, 2615, 2616, 2617, 2618, 2619, 2620, 2621, 2622, 2623, 2624, 2625, 2626, 2627, 2628, 2629, 2630, 3707, 3708, 10194, 10244, 10246, 10247, 10248, 10249, 10426, 10428, 27602, 27603, 28587, 28588, 28589, 28590, 28591, 28592, 28593, 28594, 28595, 28596, 28597, 28598, 28599, 28600, 28601, 28602, 28603, 28604, 28605, 28606, 28607, 28608, 28609, 28610, 28611, 28612, 28613, 28614, 28615, 28616, 28617, 28618, 28619, 28620, 28621, 28622, 28623, 28624, 28625, 28626, 28627, 28628, 28629, 28630, 28631, 28632, 28633, 28634, 28635, 28636, 28637, 28638, 28639, 28640, 28641, 28642, 28643) )
将它们放在 table 中，在其上创建一个索引，然后内部连接到它而不是使用 IN
看来问题出在你的派生 table:
(
SELECT stock_transaction_id,
Group_concat(serial_id) AS serials
FROM stock_transactions_serials
GROUP BY stock_transaction_id ) STS
ON STS.stock_transaction_id = ST.id
我看不到您在查询的其他任何地方使用 serials，所以我猜这对您没有太大帮助，但成本很高 - 左连接未使用加入时的索引。我建议将其重写为 stock_transaction_serials 上的连接，而不是派生的 table.