У меня есть несколько случаев, когда мой сложный CTE (Common Table Expressions) в десять раз медленнее, чем те же запросы, что и временные таблицы в SQL Server.
Мой вопрос здесь в том, как SQL Server обрабатывает запросы CTE, похоже, что он пытается объединить все отделенные запросы вместо хранения результатов каждого из них, а затем пытается запустить следующие. Таким образом, это может быть причиной, по которой это происходит быстрее при использовании временных таблиц.
Например:
Запрос 1: использование Common Table Expression:
;WITH Orders AS
(
SELECT
ma.MasterAccountId,
IIF(r.FinalisedDate IS NULL, 1, 0)) [Status]
FROM
MasterAccount ma
INNER JOIN
task.tblAccounts a ON a.AccountNumber = ma.TaskAccountId
AND a.IsActive = 1
LEFT OUTER JOIN
task.tblRequisitions r ON r.AccountNumber = a.AccountNumber
WHERE
ma.IsActive = 1
AND CAST(r.BatchDateTime AS DATE) BETWEEN @fromDate AND @toDate
AND r.BatchNumber > 0
),
StockAvailability AS
(
SELECT sa.AccountNumber,
sa.RequisitionNumber,
sa.RequisitionDate,
sa.Lines,
sa.HasStock,
sa.NoStock,
CASE WHEN sa.Lines = 0 THEN 'Empty'
WHEN sa.HasStock = 0 THEN 'None'
WHEN (sa.Lines > 0 AND sa.Lines > sa.HasStock) THEN 'Partial'
WHEN (sa.Lines > 0 AND sa.Lines <= sa.HasStock) THEN 'Full'
END AS [Status]
FROM
(
SELECT
r.AccountNumber,
r.RequisitionNumber,
r.RequisitionDate,
COUNT(rl.ProductNumber) Lines,
SUM(IIF(ISNULL(psoh.AvailableStock, 0) >= ISNULL(rl.Quantity, 0), 1, 0)) AS HasStock,
SUM(IIF(ISNULL(psoh.AvailableStock, 0) < ISNULL(rl.Quantity, 0), 1, 0)) AS NoStock
FROM task.tblrequisitions r
INNER JOIN task.tblRequisitionLines rl ON rl.RequisitionNumber = r.RequisitionNumber
LEFT JOIN ProductStockOnHandSummary psoh ON psoh.ProductNumber = rl.ProductNumber
WHERE dbo.fn_RemoveUnitPrefix(r.BatchNumber) = 0
AND r.UnitId = 1
AND r.FinalisedDate IS NULL
AND r.RequisitionStatus = 1
AND r.TransactionTypeNumber = 301
GROUP BY r.AccountNumber, r.RequisitionNumber, r.RequisitionDate
) AS sa
),
Available AS
(
SELECT ma.MasterAccountId,
SUM(IIF(ma.IsPartialStock = 1, CASE WHEN sa.[Status] IN ('Full', 'Partial') THEN 1 ELSE 0 END,
CASE WHEN sa.[Status] = 'Full' THEN 1 ELSE 0 END)) AS AvailableStock,
SUM(IIF(sa.[Status] IN ('Full', 'Partial', 'None'), 1, 0)) AS OrdersAnyStock,
SUM(IIF(sa.RequisitionDate < dbo.TicksToTime(ma.DailyOrderCutOffTime, @toDate),
IIF(ma.IsPartialStock = 1, CASE WHEN sa.[Status] IN ('Full', 'Partial') THEN 1 ELSE 0 END,
CASE WHEN sa.[Status] = 'Full' THEN 1 ELSE 0 END), 0)) AS AvailableBeforeCutOff
FROM MasterAccount ma
INNER JOIN StockAvailability sa ON sa.AccountNumber = ma.TaskAccountId
GROUP BY ma.MasterAccountId, ma.IsPartialStock
),
Totals AS
(
SELECT
o.MasterAccountId,
COUNT(o.MasterAccountId) AS BatchedOrders
FROM Orders o
GROUP BY o.MasterAccountId
)
SELECT a.MasterAccountId,
ISNULL(t.BatchedOrders, 0) BatchedOrders,
ISNULL(t.PendingOrders, 0) PendingOrders,
ISNULL(av.AvailableStock, 0) AvailableOrders,
ISNULL(av.AvailableBeforeCutOff, 0) AvailableCutOff,
ISNULL(av.OrdersAnyStock, 0) AllOrders
FROM MasterAccount a
LEFT OUTER JOIN Available av ON av.MasterAccountId = a.MasterAccountId
LEFT OUTER JOIN Totals t ON t.MasterAccountId = a.MasterAccountId
WHERE a.IsActive = 1
Запрос 2: использование временных таблиц:
DROP TABLE IF EXISTS #Orders
CREATE TABLE #Orders (MasterAccountId int, [Status] int);
INSERT INTO #Orders
SELECT
ma.MasterAccountId,
dbo.fn_GetBatchPickingStatus(ma.BatchPickingOnHold,
iif(r.GroupNumber > 0, 1, 0),
iif(r.FinalisedDate is null, 1, 0)) [Status]
FROM MasterAccount ma (nolock)
INNER JOIN wh3.dbo.tblAccounts a (nolock) on a.AccountNumber = dbo.fn_RemoveUnitPrefix(ma.TaskAccountId) and a.IsActive = 1
LEFT OUTER JOIN wh3.dbo.tblRequisitions r (nolock) on r.AccountNumber = a.AccountNumber
WHERE cast(r.BatchDateTime as date) between @fromDate and @toDate
AND r.BatchNumber > 0
AND ma.IsActive = 1
DROP TABLE IF EXISTS #StockAvailability
Create Table #StockAvailability (AccountNumber int, RequisitionNumber int, RequisitionDate datetime, Lines int, HasStock int, NoStock int);
Insert Into #StockAvailability
SELECT
r.AccountNumber,
r.RequisitionNumber,
r.RequisitionDate,
COUNT(rl.ProductNumber) Lines,
SUM(IIF(ISNULL(psoh.AvailableStock, 0) >= ISNULL(rl.Quantity, 0), 1, 0)) AS HasStock,
SUM(IIF(ISNULL(psoh.AvailableStock, 0) < ISNULL(rl.Quantity, 0), 1, 0)) AS NoStock
FROM WH3.dbo.tblrequisitions r (nolock)
INNER JOIN WH3.dbo.tblRequisitionLines rl (nolock) ON rl.RequisitionNumber = r.RequisitionNumber
LEFT JOIN ProductStockOnHandSummary psoh (nolock) ON psoh.ProductNumber = rl.ProductNumber -- Joined with View
WHERE r.BatchNumber = 0
AND r.FinalisedDate is null
AND r.RequisitionStatus = 1
AND r.TransactionTypeNumber = 301
GROUP BY r.AccountNumber, r.RequisitionNumber, r.RequisitionDate
DROP TABLE IF EXISTS #StockAvailability2
Create Table #StockAvailability2 (AccountNumber int, RequisitionNumber int, RequisitionDate datetime, Lines int, HasStock int, NoStock int, [Status] nvarchar(7));
Insert Into #StockAvailability2
SELECT sa.AccountNumber,
sa.RequisitionNumber,
sa.RequisitionDate,
sa.Lines,
sa.HasStock,
sa.NoStock,
CASE WHEN sa.Lines = 0 THEN 'Empty'
WHEN sa.HasStock = 0 THEN 'None'
WHEN (sa.Lines > 0 AND sa.Lines > sa.HasStock) THEN 'Partial'
WHEN (sa.Lines > 0 AND sa.Lines <= sa.HasStock) THEN 'Full'
END AS [Status]
FROM #StockAvailability sa
DROP TABLE IF EXISTS #Available
Create Table #Available (MasterAccountId int, AvailableStock int, OrdersAnyStock int, AvailableBeforeCutOff int);
INSERT INTO #Available
SELECT ma.MasterAccountId,
SUM(IIF(ma.IsPartialStock = 1, CASE WHEN sa.[Status] IN ('Full', 'Partial') THEN 1 ELSE 0 END,
CASE WHEN sa.[Status] = 'Full' THEN 1 ELSE 0 END)) AS AvailableStock,
SUM(IIF(sa.[Status] IN ('Full', 'Partial', 'None'), 1, 0)) AS OrdersAnyStock,
SUM(IIF(sa.RequisitionDate < dbo.TicksToTime(ma.DailyOrderCutOffTime, @toDate),
IIF(ma.IsPartialStock = 1, CASE WHEN sa.[Status] IN ('Full', 'Partial') THEN 1 ELSE 0 END,
CASE WHEN sa.[Status] = 'Full' THEN 1 ELSE 0 END), 0)) AS AvailableBeforeCutOff
FROM MasterAccount ma (NOLOCK)
INNER JOIN #StockAvailability2 sa ON sa.AccountNumber = dbo.fn_RemoveUnitPrefix(ma.TaskAccountId)
GROUP BY ma.MasterAccountId, ma.IsPartialStock
;WITH Totals AS
(
SELECT
o.MasterAccountId,
COUNT(o.MasterAccountId) AS BatchedOrders,
SUM(IIF(o.[Status] IN (0,1,2), 1, 0)) PendingOrders
FROM #Orders o (NOLOCK)
GROUP BY o.MasterAccountId
)
SELECT a.MasterAccountId,
ISNULL(t.BatchedOrders, 0) BatchedOrders,
ISNULL(t.PendingOrders, 0) PendingOrders,
ISNULL(av.AvailableStock, 0) AvailableOrders,
ISNULL(av.AvailableBeforeCutOff, 0) AvailableCutOff,
ISNULL(av.OrdersAnyStock, 0) AllOrders
FROM MasterAccount a (NOLOCK)
LEFT OUTER JOIN #Available av (NOLOCK) ON av.MasterAccountId = a.MasterAccountId
LEFT OUTER JOIN Totals t (NOLOCK) ON t.MasterAccountId = a.MasterAccountId
WHERE a.IsActive = 1
