Good finmath books
Theory of financial risk and derivative pricing
Modeling Derivatives in C++
Fast insert
Because of locking and serialization, plus logging inserting once is much more faster than inserting by loop. Here i have tested it using CTE
WITH
– second CTE which returns 100 million rows by using
– a CROSS JOIN on the first CTE
, dig AS (
SELECT
(millions.Number * 1000000)
+ (hThousands.Number * 100000)
+ (tThousands.Number * 10000)
+ (thousands.Number * 1000)
+ (hundreds.Number * 100)
+ (tens.Number * 10)
+ ones.Number AS Number
FROM digits AS ones
CROSS JOIN digits AS tens
CROSS JOIN digits AS hundreds
CROSS JOIN digits AS thousands
CROSS JOIN digits AS tThousands
CROSS JOIN digits AS hThousands
CROSS JOIN digits AS millions
)
– Third CTE which generates a “number”. repeated after 50M
, nums AS (
SELECT number
FROM dig
WHERE number <5000000
)
– the insert statement goes here
INSERT Test.dbo.PerformanceTester (col1,col2,col3)
SELECT number,number, number
FROM nums
and performance gain is more than 40 times. Cool. but this query is bound to memory and if we try to increase 5M to 50M, will complain about revising long running transactions. My trick to this is
insert
which basically doubles size of the table by 2 much faster.
into Test.dbo.PerformanceTester(col1,col2,col3)
select col1,col2,col3 from Test.dbo.PerformanceTester
– first CTE which returns 10 rows (0-9)
digits AS (
SELECT 0 as Number
UNION SELECT 1
UNION SELECT 2
UNION SELECT 3
UNION SELECT 4
UNION SELECT 5
UNION SELECT 6
UNION SELECT 7
UNION SELECT 8
UNION SELECT 9
)
SQL Server: How to get all table columns?
select column_name
from information_schema.columns
where table_name = ’my_table_name’
Dependency Injection
A object holds reference to certain interface and object, therefore by setting it is a way of injecting dependency. Really simple example at http://en.wikipedia.org/wiki/Dependency_injection.
It is somehow related with IoC, where Hollywood principle “Don’t call us, we’ll call you” works
-
Recent
-
Links
-
Archives
- August 2009 (1)
- July 2009 (2)
- April 2009 (4)
- March 2009 (6)
- February 2009 (5)
- January 2009 (4)
- December 2008 (3)
- November 2008 (35)
- October 2008 (20)
-
Categories
-
RSS
Entries RSS
Comments RSS