As far as I know there is very little difference between the two except syntax. You have to use:
CALL METHOD for AMDP
CALL DATABASE PROCEDURE for HANA Procedure
Is the AMDP performance affected by the fact it is run at ABAP Application Server?
Can this architectural downside be overcome by the SQL optimizations when comparing to HANA proc? What is the best entity to use (AMDP or HANA proc) when dealing with complex queries with multiple WITH and JOIN?
AMDP is the abbreviation of ABAP Managed Database Procedure
As the name implies, these are still database procedures, but more easy to create, maintain and transport, as they are stored in the Dictionary.
If you look into the definition of one, you will immediately see that the body is written in sqlscript1, the language that SAP uses for HANA DB procedures. It will run on the database.
There is no performance difference. If you can write efficient DB procedures, you can write efficient AMDP.
How to make them faster
Create a PlanViz file, check where the time is spent. Most often the JOIN conditions can be improved, sometimes a field is missing, or it is performed on calculated fields.
or L, or R, but never in ABAP
I have a stored procedure, in one database within my SQL server, that sets permissions to all stored procedures at once for that particulat database. Is there a way to create this stored procedure in a way were I can call it easily from any database within the SQL server and if so how do I go about doing such a thing
While the best solution to this specific question of granting execute to all procedures is the one provided by marc_s, the actual question was is there a way to create a single stored procedure and make it available to all databases.
The way to do this is documented at https://nickstips.wordpress.com/2010/10/18/sql-making-a-stored-procedure-available-to-all-databases/:
Create the stored procedure in the master database.
It must be named to start with sp_, e.g. sp_MyCustomProcedure
Execute sys.sp_MS_marksystemobject passing the name of the procedure, e.g. EXEC sys.sp_MS_marksystemobject sp_MyCustomProcedure
Here is a simple example which just selects the name of the current database:
use master
go
create procedure dbo.sp_SelectCurrentDatabaseName as begin
select db_name()
end
go
execute sys.sp_MS_marksystemobject sp_SelectCurrentDatabaseName
go
Calling exec dbo.sp_SelectCurrentDatabaseName on any database will then work.
To mark the procedure as not a system object, there a some nasty hacks suggested at https://social.msdn.microsoft.com/Forums/sqlserver/en-US/793d0add-6fd9-43ea-88aa-c0b3b89b8d70/how-do-i-undo-spmsmarksystemobject?forum=sqltools but it is safest and easiest to just drop and re-create the procedure.
Caveat
Of course creating system procedures like this is breaking the common rule of not naming your own procedures as sp_xxx, due to the possibility of them conflicting with built-in procedures in future versions of SQL Server. Therefore this should be done with care and not just create a load of randomly named procedures which you find useful.
A common simple way to avoid this is to add your own company/personal prefix to the procedure which Microsoft is unlikely to use, e.g. sp_MyCompany_MyCustomProcedure.
I have a stored procedure, in one database within my SQL server, that
sets permissions to all stored procedures at once for that particular
database.
You could archive the same result much easier:
create a new role, e.g. db_executor
CREATE ROLE db_executor
grant that role execute permissions without specifying any objects:
GRANT EXECUTE TO db_executor
This role now has execute permissions on all stored procedures and functions - and it will even get the same permissions for any future stored procedure that you add to your database!
Just assign this role to the users you need and you're done....
Have you tried a 3 or 4 part name?
InstanceName.DatabaseName.dbo.usp_Name
That procedure could in turn reference objects in other databases using the same conventions. So you could parameterize the name of the database to be operated on and use dynamic SQL to generate 4 part names to reference objects such as system tables.
I am using SQL Server 2008 Enterprise on Windows Server 2008 Enterprise. In a stored procedure, we can execute a SELECT statement directly. And it could also be executed in this new way, I am wondering which method is better, and why?
New method,
declare #teststatement varchar(500)
set #teststatement = 'SELECT * from sometable'
print #teststatement
exec (#teststatement)
Traditional method,
SELECT * from sometable
regards,
George
FYI: it’s not a new method, it is known as Dynamic SQL.
Dynamic SQL are preferred when we need to set or concatenate certain values into sql statements.
Traditional or normal way sql statements are recommended, because stored procedures are complied. Complied on first run "Stored Procedure are Compiled on First Run"
, execution plan of statements are being created at the time of compilation.
Dynamic sqls are ignored while creating execution plans, because it is taken as string (VARCHAR or NVARCHAR as declared).
Refer following articles for more details about dynamic query and stored procs
Introduction to Dynamic SQL Part 1
Introduction to Dynamic SQL Part 2
Everything you wanted to know about Stored Procedures
The traditional method is safer, because the query is parsed when you save it. The query in the 'exec' method is not parsed and can contain errors.
The "new" way, as mentioned, has nothing to do with SQL 2008. EXEC has been available for quite some time. It's also - in most cases - a Very Bad Idea.
You lose parameterization - meaning you are now vulnerable to SQL Injection. It's ugly and error-prone. It's less efficient. And it creates a new execution scope - meaning it can't share variables, temp tables, etc. - from it's calling stored proc.
sp_executesql is another (and preferred) method of executing dynamic SQL. It's what your client apps use, and it supports parameters - which fixes the most glaring problem of EXEC. However, it too has very limited use cases within a stored proc. About the only redeeming use is when you need a dynamic table or column name. T-SQL does not support a variable for that - so you need to use sp_executesql. The number of times you need or should be doing that are very low.
Bottom line - you'd be best off forgetting you ever heard of it.
I have some doubt regarding user defined functions. I would like to know why / when to use functions.
What are the advantages of functions over stored procedure?
Researching via google I have seen articles suggesting:
stored procedure are more advantageous than functions.
function have limited error handling
functions cannot use temporary tables
functions cannot call stored procedures.
The only advantage of function is we can use function as inline queries.
I can get the same result with stored procedure by using temporary tables, but i need to know which scenario to use functions compared to stored procedure.
I need to know why we need UDf , when most of the functionalities provided by UDF can be done by Stored procedure.
Can any one guide me over this.
The main difference (advantage) is that you can call functions inline unlike stored procedures
e.g.
SELECT dbo.fxnFormatName(FirstName, LastName) AS FormattedName
FROM MyTable
SELECT *
FROM dbo.fxnTableReturningFunction() x
User defined functions can return TABLE type data and then the function can then be called within a query as demonstrated above. With a sproc, you'd have to execute it and store the results into a temporary table in order to then manipulate/query the resultset further.
On the flip side, yes you are limited as to what you can do in a function. e.g. you can't use dynamic sql, and pre-SQL 2005 you can't use non-deterministic functions like GETDATE() within a function.
An example of when you may want to use functions, is to wrap up common "formatting" functionality as shown in the first example above - rather than repeat the logic to format a first and last name into one in every query, you wrap it in a function and call that everywhere. Typically I'd recommend leaving the formatting up to the UI but it's a simple example of where/why you might use.
Also, it can often be nicer to not have to create temp tables to hold results from a sproc in order to query it further. If the sproc changes and returns more columns, you'd also need to change everywhere that loads the results into a temp table to synch the schema of the table table it uses to hold the results with the new schema returned. You don't have this problem with the function approach as there is no temp table to be maintained.
There are three types of functions: Scalar, Inline Table and Table Valued. Generally speaking, Scalar & Table Values functions can lead to performance problems, seeing as the Query Optimiser doesn't do very well at optimisation of the use of those types of functions. The performance of Inline Table function is just fine, however.
There is a Connect request to create a new type of scalar function here: The Scalar Expression function would speed performance...
I hope that people do vote for that one, because it would improve performance greatly by allowing the query optimiser to inline functional expressions and take advantage of statistics etc just as it would for a normal query.
The main "disadvantage" of user-defined functions is that they are called for each row. So, if you have such a function in the SELECT list and you're operating on larger sets, there are good chances that your performance will suffer.
Advantage of Mysql Stored Procedure
Multiple applications are running in multiple environment and need to use the same database. By using stored procedure you can make your business logic independent of programming language.
When security is main concern use of stored procedure is vital. By doing your operation through the database you can log your all performed action. Banking site is the best example.
If you are using stored procedure then you do not have table access directly which is one more way to secure the data and transaction.
Stored procedure increases performance of your application sometime
If your application is big or your database server on remote system then by using stored procedure you can decrease the traffic between your database server and application server.
Since stored procedure is written in your database server and application call it sepratly then the degree of re-usability.
What is a "stored procedure" and how do they work?
What is the make-up of a stored procedure (things each must have to be a stored procedure)?
Stored procedures are a batch of SQL statements that can be executed in a couple of ways. Most major DBMs support stored procedures; however, not all do. You will need to verify with your particular DBMS help documentation for specifics. As I am most familiar with SQL Server I will use that as my samples.
To create a stored procedure the syntax is fairly simple:
CREATE PROCEDURE <owner>.<procedure name>
<Param> <datatype>
AS
<Body>
So for example:
CREATE PROCEDURE Users_GetUserInfo
#login nvarchar(30)=null
AS
SELECT * from [Users]
WHERE ISNULL(#login,login)=login
A benefit of stored procedures is that you can centralize data access logic into a single place that is then easy for DBA's to optimize. Stored procedures also have a security benefit in that you can grant execute rights to a stored procedure but the user will not need to have read/write permissions on the underlying tables. This is a good first step against SQL injection.
Stored procedures do come with downsides, basically the maintenance associated with your basic CRUD operation. Let's say for each table you have an Insert, Update, Delete and at least one select based on the primary key, that means each table will have 4 procedures. Now take a decent size database of 400 tables, and you have 1600 procedures! And that's assuming you don't have duplicates which you probably will.
This is where using an ORM or some other method to auto generate your basic CRUD operations has a ton of merit.
A stored procedure is a set of precompiled SQL statements that are used to perform a special task.
Example: If I have an Employee table
Employee ID Name Age Mobile
---------------------------------------
001 Sidheswar 25 9938885469
002 Pritish 32 9178542436
First I am retrieving the Employee table:
Create Procedure Employee details
As
Begin
Select * from Employee
End
To run the procedure on SQL Server:
Execute Employee details
--- (Employee details is a user defined name, give a name as you want)
Then second, I am inserting the value into the Employee Table
Create Procedure employee_insert
(#EmployeeID int, #Name Varchar(30), #Age int, #Mobile int)
As
Begin
Insert Into Employee
Values (#EmployeeID, #Name, #Age, #Mobile)
End
To run the parametrized procedure on SQL Server:
Execute employee_insert 003,’xyz’,27,1234567890
--(Parameter size must be same as declared column size)
Example: #Name Varchar(30)
In the Employee table the Name column's size must be varchar(30).
A stored procedure is a group of SQL statements that has been created and stored in the database. A stored procedure will accept input parameters so that a single procedure can be used over the network by several clients using different input data. A stored procedures will reduce network traffic and increase the performance. If we modify a stored procedure all the clients will get the updated stored procedure.
Sample of creating a stored procedure
CREATE PROCEDURE test_display
AS
SELECT FirstName, LastName
FROM tb_test;
EXEC test_display;
Advantages of using stored procedures
A stored procedure allows modular programming.
You can create the procedure once, store it in the database, and call it any number of times in your program.
A stored procedure allows faster execution.
If the operation requires a large amount of SQL code that is performed repetitively, stored procedures can be faster. They are parsed and optimized when they are first executed, and a compiled version of the stored procedure remains in a memory cache for later use. This means the stored procedure does not need to be reparsed and reoptimized with each use, resulting in much faster execution times.
A stored procedure can reduce network traffic.
An operation requiring hundreds of lines of Transact-SQL code can be performed through a single statement that executes the code in a procedure, rather than by sending hundreds of lines of code over the network.
Stored procedures provide better security to your data
Users can be granted permission to execute a stored procedure even if they do not have permission to execute the procedure's statements directly.
In SQL Server we have different types of stored procedures:
System stored procedures
User-defined stored procedures
Extended stored Procedures
System-stored procedures are stored in the master database and these start with a sp_ prefix. These procedures can be used to perform a variety of tasks to support SQL Server functions for external application calls in the system tables
Example: sp_helptext [StoredProcedure_Name]
User-defined stored procedures are usually stored in a user database and are typically designed to complete the tasks in the user database. While coding these procedures don’t use the sp_ prefix because if we use the sp_ prefix first, it will check the master database, and then it comes to user defined database.
Extended stored procedures are the procedures that call functions from DLL files. Nowadays, extended stored procedures are deprecated for the reason it would be better to avoid using extended stored procedures.
Generally, a stored procedure is a "SQL Function." They have:
-- a name
CREATE PROCEDURE spGetPerson
-- parameters
CREATE PROCEDURE spGetPerson(#PersonID int)
-- a body
CREATE PROCEDURE spGetPerson(#PersonID int)
AS
SELECT FirstName, LastName ....
FROM People
WHERE PersonID = #PersonID
This is a T-SQL focused example. Stored procedures can execute most SQL statements, return scalar and table-based values, and are considered to be more secure because they prevent SQL injection attacks.
Think of a situation like this,
You have a database with data.
There are a number of different applications needed to access that central database, and in the future some new applications too.
If you are going to insert the inline database queries to access the central database, inside each application's code individually, then probably you have to duplicate the same query again and again inside different applications' code.
In that kind of a situation, you can use stored procedures (SPs). With stored procedures, you are writing number of common queries (procedures) and store them with the central database.
Now the duplication of work will never happen as before and the data access and the maintenance will be done centrally.
NOTE:
In the above situation, you may wonder "Why cannot we introduce a central data access server to interact with all the applications? Yes. That will be a possible alternative. But,
The main advantage with SPs over that approach is, unlike your data-access-code with inline queries, SPs are pre-compiled statements, so they will execute faster. And communication costs (over networks) will be at a minimum.
Opposite to that, SPs will add some more load to the database server. If that would be a concern according to the situation, a centralized data access server with inline queries will be a better choice.
A stored procedure is mainly used to perform certain tasks on a database. For example
Get database result sets from some business logic on data.
Execute multiple database operations in a single call.
Used to migrate data from one table to another table.
Can be called for other programming languages, like Java.
A stored procedure is nothing but a group of SQL statements compiled into a single execution plan.
Create once time and call it n number of times
It reduces the network traffic
Example: creating a stored procedure
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE PROCEDURE GetEmployee
#EmployeeID int = 0
AS
BEGIN
SET NOCOUNT ON;
SELECT FirstName, LastName, BirthDate, City, Country
FROM Employees
WHERE EmployeeID = #EmployeeID
END
GO
Alter or modify a stored procedure:
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE GetEmployee
#EmployeeID int = 0
AS
BEGIN
SET NOCOUNT ON;
SELECT FirstName, LastName, BirthDate, City, Country
FROM Employees
WHERE EmployeeID = #EmployeeID
END
GO
Drop or delete a stored procedure:
DROP PROCEDURE GetEmployee
A stored procedure is used to retrieve data, modify data, and delete data in database table. You don't need to write a whole SQL command each time you want to insert, update or delete data in an SQL database.
A stored procedure is a precompiled set of one or more SQL statements which perform some specific task.
A stored procedure should be executed stand alone using EXEC
A stored procedure can return multiple parameters
A stored procedure can be used to implement transact
"What is a stored procedure" is already answered in other posts here. What I will post is one less known way of using stored procedure. It is grouping stored procedures or numbering stored procedures.
Syntax Reference
; number as per this
An optional integer that is used to group procedures of the same name. These grouped procedures can be dropped together by using one DROP PROCEDURE statement
Example
CREATE Procedure FirstTest
(
#InputA INT
)
AS
BEGIN
SELECT 'A' + CONVERT(VARCHAR(10),#InputA)
END
GO
CREATE Procedure FirstTest;2
(
#InputA INT,
#InputB INT
)
AS
BEGIN
SELECT 'A' + CONVERT(VARCHAR(10),#InputA)+ CONVERT(VARCHAR(10),#InputB)
END
GO
Use
exec FirstTest 10
exec FirstTest;2 20,30
Result
Another Attempt
CREATE Procedure SecondTest;2
(
#InputA INT,
#InputB INT
)
AS
BEGIN
SELECT 'A' + CONVERT(VARCHAR(10),#InputA)+ CONVERT(VARCHAR(10),#InputB)
END
GO
Result
Msg 2730, Level 11, State 1, Procedure SecondTest, Line 1 [Batch Start Line 3]
Cannot create procedure 'SecondTest' with a group number of 2 because a procedure with the same name and a group number of 1 does not currently exist in the database.
Must execute CREATE PROCEDURE 'SecondTest';1 first.
References:
CREATE PROCEDURE with the syntax for number
Numbered Stored Procedures in SQL Server - techie-friendly.blogspot.com
Grouping Stored Procedures - sqlmag
CAUTION
After you group the procedures, you can't drop them individually.
This feature may be removed in a future version of Microsoft SQL Server.
for simple,
Stored Procedure are Stored Programs, A program/function stored into database.
Each stored program contains a body that consists of an SQL statement. This statement may be a compound statement made up of several statements separated by semicolon (;) characters.
CREATE PROCEDURE dorepeat(p1 INT)
BEGIN
SET #x = 0;
REPEAT SET #x = #x + 1; UNTIL #x > p1 END REPEAT;
END;
A stored procedure is a named collection of SQL statements and procedural logic i.e, compiled, verified and stored in the server database. A stored procedure is typically treated like other database objects and controlled through server security mechanism.
In a DBMS, a stored procedure is a set of SQL statements with an assigned name that's stored in the database in compiled form so that it can be shared by a number of programs.
The use of a stored procedure can be helpful in
Providing a controlled access to data (end users can only enter or change data, but can't write procedures)
Ensuring data integrity (data would be entered in a consistent manner) and
Improves productivity (the statements of a stored procedure need to be written only once)
Stored procedures in SQL Server can accept input parameters and return multiple values of output parameters; in SQL Server, stored procedures program statements to perform operations in the database and return a status value to a calling procedure or batch.
The benefits of using stored procedures in SQL Server
They allow modular programming.
They allow faster execution.
They can reduce network traffic.
They can be used as a security mechanism.
Here is an example of a stored procedure that takes a parameter, executes a query and return a result. Specifically, the stored procedure accepts the BusinessEntityID as a parameter and uses this to match the primary key of the HumanResources.Employee table to return the requested employee.
> create procedure HumanResources.uspFindEmployee `*<<<---Store procedure name`*
#businessEntityID `<<<----parameter`
as
begin
SET NOCOUNT ON;
Select businessEntityId, <<<----select statement to return one employee row
NationalIdNumber,
LoginID,
JobTitle,
HireData,
From HumanResources.Employee
where businessEntityId =#businessEntityId <<<---parameter used as criteria
end
I learned this from essential.com...it is very useful.
Stored Procedure will help you to make code in server.You can pass parameters and find output.
create procedure_name (para1 int,para2 decimal)
as
select * from TableName
In Stored Procedures statements are written only once and reduces network traffic between clients and servers.
We can also avoid Sql Injection Attacks.
Incase if you are using a third party program in your application for
processing payments, here database should only expose the
information it needed and activity that this third party has been
authorized, by this we can achieve data confidentiality by setting
permissions using Stored Procedures.
The updation of table should only done to the table it is targeting
but it shouldn't update any other table, by which we can achieve
data integrity using transaction processing and error handling.
If you want to return one or more items with a data type then it is
better to use an output parameter.
In Stored Procedures, we use an output parameter for anything that
needs to be returned. If you want to return only one item with only
an integer data type then better use a return value. Actually the
return value is only to inform success or failure of the Stored
Procedure.
Preface: In 1992 the SQL92 standard was created and was popularised by the Firebase DB. This standard introduced the 'Stored Procedure'.
**
Passthrough Query: A string (normally concatenated programatically) that evaluates to a syntactically correct SQL statement, normally generated at the server tier (in languages such as PHP, Python, PERL etc). These statements are then passed onto the database.
**
**
Trigger: a piece of code designed to fire in response to a database event (typically a DML event) often used for enforcing data integrity.
**
The best way to explain what a stored procedure is, is to explain the legacy way of executing DB logic (ie not using a Stored Procedure).
The legacy way of creating systems was to use a 'Passthrough Query' and possibly have triggers in the DB.
Pretty much anyone who doesn't use Stored Procedures uses a thing call a 'Passthrough Query'
With the modern convention of Stored Procedures, triggers became legacy along with 'Passthrough Queries'.
The advantages of stored procedures are:
They can be cached as the physical text of the Stored Procedure
never changes.
They have built in mechanisms against malicious SQL
injection.
Only the parameters need be checked for malicious SQL
injection saving a lot of processor overhead.
Most modern database
engines actually compile Stored Procedures.
They increase the
degree of abstraction between tiers.
They occur in the same
process as the database allowing for greater optimisation and
throughput.
The entire workflow of the back end can be tested
without client side code. (for example the Execute command in
Transact SQL or the CALL command in MySQL).
They can be used to
enhance security because they can be leveraged to disallow the
database to be accessed in a way that is inconsistent with how the
system is designed to work. This is done through the database user
permission mechanism. For example you can give users privileges only
to EXECUTE Stored Procedures rather that SELECT, UPDATE etc
privileges.
No need for the DML layer associated with triggers. **
Using so much as one trigger, opens up a DML layer which is very
processor intensive **
In summary when creating a new SQL database system there is no good excuse to use Passthrough Queries.
It is also noteworthy to mention that it is perfectly safe to use Stored Procedures in legacy systems that already uses triggers or Passthrough Queries; meaning that migration from legacy to Stored Procedures is very easy and such migration need not take a system down for long if at all.
create procedure <owner>.<procedure name><param> <datatype>
As
<body>
Stored procedure are groups of SQL statements that centralize data access in one point. Useful for performing multiple operations in one shot.