How many rows can SQL Server process in a single INSERT statement into a table?
-
18-01-2021 - |
题
To illustrate my question, the following is a query detecting order's id which have not been inserted in a data warehouse and inserts them:
With NewOrders
As
(
Select OrderID From Orders
Except
Select OrderID From FactOrders
)
Insert Into FactOrders(OrderID, OrderDate, CustomerId)
Select OrderID, OrderDate, CustomerId From Orders
Where OrderID in (Select OrderID from NewOrders);
Say the query is run for the first time and Orders
contains 400 million rows or more:
Can SQL Server handle this number of rows in one single INSERT
statement?
If not, how should I proceed? Should I limit the number of rows fetched in the INSERT
statement? How many rows can the engine handle in a single INSERT
statement?
解决方案
According to the documentation the only limitation on the number of rows stored per table is as below
Limited only by available resources
What local resources does this potentially include?
- Memory
- Space in the database data files to physically write the inserted data to
- Space in the database log files
- Space in TempDB (Data and log)
As for how much a single SELECT statement can extract, I cannot find any documentation pertaining to this directly, but I would assume it is safe to take this to be exactly the same as the above.
其他提示
There does not appear to be a row limit except as it relates to resources. If your SQL Server truly have enough resources to insert half a billion rows then it will do it. In the past, I have been faced with such resource constraints, so I would add a WHERE clause that limited the resultset. Or I would run the INSERT recursively with a TOP on the select.
With NewOrders
As
(
Select OrderID From Orders
Except
Select OrderID From FactOrders
)
Insert Into FactOrders(OrderID, OrderDate, CustomerId)
Select **TOP 1000000** OrderID, OrderDate, CustomerId
From Orders
Where OrderID in (Select OrderID from NewOrders);