Poor performance with sql server on azure vm when I write a lot of data to disk

Question

I need to move an existing application to windows azure VMs. This application write a lot of data (insert into) to DB.

So, I created a SQL Server machine on Azure VM, and configured the environment according the Microsoft best practice for SQL Server on azure VM ( http://msdn.microsoft.com/en-us/library/azure/dn133149.aspx ).

I tested this SQL query on my computer and on my SQL Server on azure VM:

WHILE @i <= 100000 BEGIN
INSERT INTO sales (id, created) VALUES (@i, GETDATE());
SET @i = @i + 1;
END

When I run this query on my machine, its finished after 43 seconds. When I run this query on the azure VM its take over 10 minutes!!! (I try this with single disk and striped with 2 and 4 disks).

I try to test more scenario code, with transaction:

WHILE @i <= 100000 BEGIN

-- Start a transaction
IF @i % 10000 = 1 
   BEGIN TRANSACTION;

 INSERT INTO sales (id) VALUES (@i);
 SET @i = @i + 1;

-- Commit after each 10,000 row
IF @i % 10000 = 0
  COMMIT;
END

this scenario works OK on both environments (my pc & azure VM).

When I ran SQLIO on the sql azure VM server, I got results that fit to the second query results (with transaction).

My application must run without transactions.

Anybody know how to resolve that? Thank you.

Answer 1

100.000 inserts one by one will be slow, because of the many inserts within the same transaction. Try this instead. It only has 1 insert:

;WITH d as
(
  SELECT rn
  FROM (values(1),(2),(3),(4),(5),(6),(7),(8),(9),(0)) x(rn)
), numbers as
(
  SELECT 
    row_number() over (order by (select 1)) rn
  FROM d d1,d d2,d d3,d d4,d d5
)
INSERT sales (id, created)
SELECT 
  rn,
  getdate()
FROM
  numbers