Multi thread D/B access design.

Hi,
I'm trying to performance test a 3 tiered design from client > TCP/IP to Server > ODBC to MSQL.
I have a multi thread requesting client which connects via sockets to the server.
The server kicks off multithread servelets which create a connection via ODBC ( Or reuse an existing one ) and communicates the data back to the requesting client.
However, no matter the number of threads/ports/connections/ODBC data sources/Device managers I use I always get a linear progression for the data I am accessing.
ie 1 file of 1000 records is 390 milliseconds, 10 is 4600 milliseconds etc.
Is there somethings simple I'm missing out to make the access to the server linear ?
The only option I'm considering at the moment is that the MSQL V 7.0 I have is the free one with visual studio and so has been "enhanced" to provide reduced performance.
Any ideas ?
Cheers,
Gary

The answer to you question is JDBC-ODBC BRIDGE IS SYNCHRONIZED..meaning it is SINGLE THREADED. No matter how many threads you create to access your database, only one thread enters the monitor at a time. The monitor I am referring to is the process space allocated to the thread at any given time, in your case I am referring to the process space as the particular lines of code which are responsible for database access. Your problem can be solved if you go for other database drivers( like type 4 drivers ). There are a variety of mutithreadd drivers available for most of the databases. I have raised this question at Sun Seminars also , and apparently this seems to be the only solution..
Cheers,
Shafique Razzaque,
Senior Apps Developer,
Singapore.

Similar Messages

Using multi threading to access 2 RS232 ports

Hi,
I'm a beginner in multi threading, so this question may be a very basic one....
I'm Using TS3.5 + CVI 8.01 to communicate withs 2 RS232 ports. I thought to use mult threading so I can process 2 steps in parallel rather than in series.
This is what I do:
1) I defined 2 subsequences, each of them call the same CVI function. I use the sub sequence parameters to transfer the com number.
2) My CVI application includes one dll for this specific project and another one, a general dll to handle RS232 functions. The RS232 dll uses one global buffer than collects all the traffic on the com.
QUESTIONS:
1) What happens when 2 seperate threads run the same function in the RS232 dll? (in terms of memory etc...). Does each one use a different buffer (in terms of memory allocation), or, both of them writes to the same buffer? Obviously, if they writes to the same buffer, then, my function will not operate properly.
2) What happens in TestStand after the 2 steps in new threads have finished their execution? does the next step run back in the same threads the sequence run before?
Thanks
Rafi

Rafi,
Glad to hear you were able to make some ground on your application. As for all of your questions, I'll try to answer as many as I can.
First, when you are talking about your global buffer, is it created in TestStand or in the DLL itself? When you use DLLs, global variables or global structures are shared between all threads that call your DLL. On the other hand, if your buffer is declared inside of the DLL it is global for the DLL but not shared and would be a separate buffer for each call.
With your run-time error in TS, it would definitely be helpful to have more information about the error. From what you explained (executing fine on the first call, but failing on future executions), it sounds like the resource is not being released after the first execution.
As far as a specific example for TestStand Multithreading, you'll want to look at the TestStand Development Library and, specifically, Multithreading in TestStand. If you look and browse through the Application Notes and Tutorials section, as well as the Technical Presentations section, you will learn a great deal about multithreading and what options you have in TestStand. For a specific example, you may want to look at This Example. You could also look in the <TestStand>\Examples (where <TestStand> is the directory where TS is installed) at the MultiUUT example for an example of multithreading in TS. These examples may not be exactly what you need, but they should give you a jump start.
As far as making your DLL multithread safe, it is definitely not necessary; however, there are some significant advantages described in this article: Designing Thread-Safe DLLs. It is an MSDN article that focuses on Visual Basic, but it has some helpful information that can apply to C as well.
Hopefully this can help you move further. I have attached a list of links at the end of this post with other helpful links for you as well. Keep us posted with your progress.
Matt Mueller
NI
Links:
General Information on Multithreading for C Programmers
Building Multithreading Applications with LabWindows/CVI
Multithreading in LabWindows/CVI
Easy Multithreading Programming in LabWindows/CVI
Multithreading for Rookies

Multiple Containers read/write access in multi-threaded environment

I'm been reading the Berkeley DB XML Transaction Processing document and have a few questions. I have a multi-threaded environment (not multi-process).
1) In the "Summary and Examples" section, there is an example of several worker threads that perform many writes to a shared container. The one container is passed to all the worker threads, rather them having their own instance of the container. In my application, I could potentially have multiple worker threads acting on the same container, is it better to provide some type of connection pool, so each thread has access to the same container? Is their a problem with each thread creating a new instance of the container and writing to that? Is their pros and cons to each approach?
2) In some specific web applications, they only require read-access and have no intention of writing to the database. If the environment was created with transactions, can these applications open the environment in read-only mode, so as to not suffer the performance penalty of using transactions? Or do they still require transaction support since other threads in other applications might be writing to it. Is it better in this case to
3) Is there any decent connection pooling framework that work well with BDB XML? If transactions are involved, it seems pretty important to always close the container once you are finished with it, which kind of defeats the purpose of pooling. I see a container somewhat analogous to a JDBC transaction, where in connection pooling these transactions remain open, but in BDB XML, it doesn't seem like this is good practice. So clarification here would be appreciated.
Thanks in advance...
Chris

Chris,
I'd be careful about trying to draw too many analogies with other sorts of systems. In many ways BDB XML is simpler -- it's just a library, no server process.
An open container is analogous to an open file handle/descriptor in your operating system. It can safely be shared by all threads within a given process. In fact, you should not create more than one -- while that works, it can just be confusing, and a source of errors (for example, if you use a different path to open the container each time, you'll have problems). So by all means share them. Most Java applications just point them in a class that is accessible to all threads.
Other objects that can, and should be shared among threads include:
Environment
XmlManager
XmlQueryExpression
Most others should not. You also mention closing your containers -- there is no reason to close your active container objects until your application needs to shut down. A long-running application will want to use db_checkpoint (or equivalent) to ensure that modified pages are flushed from the transaction log to the database files, but that's about it.
As for concurrency, you obviously need transactions for concurrent write operations. If you want concurrent read access to the same containers, they should use transactions as well. Even if you don't explicitly use transactions, locks are always taken on pages in transactional containers. You cannot open the same container transactionally and not transactionally at the same time -- bad things could happen.
Depending on your performance needs, you could using snapshot concurrency, and see how it works for you. While locking does incur some overhead, it may be acceptable.
You mention creating your own "snapshot" of a container and running read-only on that copy. That's possible to do, but you have to be careful of how you create the snapshot (following hot backup procedures). Also, if you intend to open that "new" container in the same environment or application as the old one, you need to run a program on it to change its internal identification so Berkeley DB won't think it's the same file. That is, you can't just copy a container file to a new name and just open it like it's a new container if it's still in the vicinity of the original. See the -r option for the db_load program.
Now that you are probably really confused, good luck!
Regards,
George

Multi-thread failure - Error in assignment

Hello
I have a c++ program processor running under Windows XP with Oracle 9i. My program access to oracle by an ODBC driver version 9.2.0.4.0. It could be launched in multi-thread to increase performance. When I launch it with one thread everything is fine. When I use several threads I have problems. ODBC driver returns to me a "error in assignment ... General error" message and my updates queries failed. Under SQl server it works without problems. It seems to be a kind of deadlock. When I disable check box in my odbc driver of "enable query timeout" my program encounter a problem and freezes...
Could someone help me ?

user13335017 wrote:
I have thought of the above solutions as workable, however, it is not. Some exhibited errors are:
A. "Attempt to use database while environment is closed." This error applies to 2, 3 and 4 all the way;
B. "Attempt to read / write database while database is closed." This error applies to 3 in particular;
C. "Attempt to close environment while some database is still open." This error applies to 5.
Please help me with designing a better strategy to solve the concurrent issue. Many thanks in advance.All these are expected errors. You should design the application so that you do not close an environment handle while database handles are still open, keep database handles open for as long as operations need to be performed on the underlying databases, open the database handles after opening the database handles, and close database handles before closing the environment handle.
In short, in pseudo-code, you should have something like this:
- open environment handle,
- open database handles,
- perform whatever operations are needed on the databases,
- close database handles,
- close environment handle.
You can refer to the Getting Started with Data Storage and the Getting Started with Transaction Processing guides appropriate for the API you are using, from the Berkeley DB documentation page.
Regards,
Andrei

Is a Trigger Multi Thread?

I’m trying to execute a SELECT statement WHERE status = X to make some operations when I insert a row in my Table.
If there is another insert until is execute the firs insert, the Trigger is executed in other Thread or waits until the first ended?
Is a Trigger Multi Thread?
If is multi thread, is possible to make it in single thread or wait until the first one end?

Each session will execute its own copy of the trigger.
To single thread access to rows within a table look at the select for update statement.
When designing transactions give thought to Oracle's read consistency model: readers will not wait on updaters to see the row contents.
But by selecting for update you will cause other sessions that want to update the same selected row as taken by the first session to wait for the first session to commit or rollback before the second session performs its update.
If you need to single thread access to the entire table you could be designing an applciation that will not scale to support multiple session access.
HTH -- Mark D Powell --

What is multi threading?

Hi all,
What is multi threading? How to implement multi threading in ABAP?
Regards,
Bryan

Hi
How the vision connector framework works
The connector interacts with an SAP application using connector modules. The connector modules make calls to SAP's Native Interfaces and pass data (business object or event data) to and from an SAP application. The connector's flexible design enables different modules to be used for different tasks such as initializing the connector with the SAP application or passing business object data.
Communication between the connector and an SAP application
The connector uses SAP's Remote Function Call (RFC) library to communicate with an SAP application. SAP's RFC API allows external programs to call ABAP function modules within an SAP application.
Processing business objects
The connector is metadata driven. Metadata, in the WebSphere business integration system, is application-specific data that is stored in business objects and that assists a connector module in its interaction with the application. A metadata-driven connector module handles each business object that it supports based on metadata encoded in the business object definition rather than on instructions hard-coded in the connector module.
Business object metadata includes the structure of a business object, the settings of its attribute properties, and the content of its application-specific information. Because connector modules are metadata driven, they can handle new or modified business objects without requiring modifications to the connector-module code.
The vision connector framework uses the value of the verb application-specific information in the top-level business object to call the appropriate connector module to process the business object. The verb application-specific information provides the classname of the connector module.
The verb application-specific information of most top-level business objects must identify the classname of the connector module. The syntax of this verb application-specific information is:
AppSpecificInfo = PartialPackageName.ClassName,
For example,
AppSpecificInfo = sap.sapextensionmodule.VSapBOHandler,
In this example, sap.sapextensionmodule is the partial package name, and VSapBOHandler is the classname. The full package name includes the com.crossworlds.connectors prefix, which the WebSphere business integration system adds to the name automatically. In other words, the full text of the example is:
com.crossworlds.connectors.sap.sapextensionmodule.VSapBOHandler
Note:
The verb application-specific information of most top-level business objects must use a comma (,) delimiter after the connector classname. However, the Server verb, which is used by the RFC Server Module, is delimited instead by a semi-colon (;). For information about the Server verb, see How the RFC Server Module works and Supported verbs.
You need not specify the package name and classname for the verb application-specific information if the business object is used:
by the ALE Module to process application events; however, when you use the ALE Module to process service call requests, you must specify the package name and classname
by the ABAP Extension Module, which uses the default business object handler (sap.sapextensionmodule.VSapBOHandler)
Important:
Customer-generated connector modules that process business objects for the RFC Server Module must specify a full package name, which must begin with bapi. For example, bapi.client.Bapi_customer_getdetail2. The full package name in this example is bapi.client, and the classname is Bapi_customer_getdetail2.
Most business object processing is specific to each connector module. By default the connector uses the ABAP Extension Module. For more information on business object processing for the ABAP Extension Module, see Installing and customizing the ABAP Extension Module and Business object data routing to ABAP handlers. .
For more information on specifying verb application-specific information for the ALE Module, see Event processing and Processing multiple IDocs with a wrapper business object.
Processing multiple concurrent interactions
The Adapter Framework can create separate threads for processing an application event and a business object request. When processing multiple requests from the integration broker, it can create multiple threads to handle multiple business object requests. For example, when InterChange Server is the integration broker, the connector can receive multiple business object requests from multiple collaborations or from a multi-threaded collaboration.
Figure 4 illustrates the multi-threading architecture.
Figure 4. Multi-Threading Architecture of the Connector for SAP
Event processing
The connector performs the following steps when handling a poll call:
The Adapter Framework creates a single dedicated thread to handle poll calls. This thread calls the pollForEvents() method of the vision connector framework at the frequency specified in the PollFrequency configuration property.
The thread polls SAP, which uses a dialog process to locate and return the event.
Note:
If the connector's MaxNumberOfConnections configuration property evaluates to a number greater than 1, the vision connector framework dedicates a connection to SAP for polling. If MaxNumberOfConnections evaluates to 1, event and service-call request processing share a single connection to SAP.
The polling thread dies only when the connector shuts down.
Note:
Because the RFC Server connector agent pushes events out of SAP instead of polling for events, it spawns its own threads instead of using threads created by the connector framework. Because the ALE connector agent uses the RFC Server connector agent to access events, it also spawns its own threads instead of using threads created by the connector framework when it processes events.
Request processing
Independently of polling, the Adapter Framework can create multiple request-processing threads, one for each request business object. Each request thread instantiates the appropriate business object handler.
For example, when processing business object requests from InterChange Server, the number and type of business object handlers depends on the number and type of the collaborations sending the requests:
If multiple collaborations send business objects, each request thread instantiates a business object handler of the appropriate type.
If a multi-threaded collaboration sends multiple business objects of the same type, the request threads instantiate an equal number of business object handlers of that type.
If the connector's MaxNumberOfConnections configuration property evaluates to a number greater than 1, the vision connector framework dedicates one connection to SAP for polling and allocates the remaining connections to a pool used only for request processing.
As illustrated in Figure 4, the connector performs the following steps when handling a business object request:
The Adapter Framework creates a separate thread for each business object request. Each thread calls the doVerbFor() method of the Vision business object handler.
If the connector's MaxNumberOfConnections configuration property evaluates to a number greater than 1, the Vision business object handler checks the vision connector framework's connection pool to determine if a connection handle is available.
If the handle is available, the thread sends the request to SAP, which uses a dialog process to handle the request.
If the handle is not available, the thread waits until one becomes available. Thread sequencing determines the order in which each business object handler thread claims or waits for an available connection handle.
If the connector's MaxNumberOfConnections configuration property evaluates to 1, the Vision business object handler shares a connection with event processing.
SAP releases the dialog process after it completes processing and sends a return code.
The connector releases the connection handle after it receives the return code from SAP.
Setting the number of available connections
Use the MaxNumberOfConnections configuration property to specify the maximum number of connection handles available. The number of connections cannot exceed the number of dialog processes.
SAP locks the dialog process while processing an interaction, releasing it only when the interaction completes. Therefore, multiple concurrent requests lock an equal number of dialog processes until processing finishes.
Important:
Before setting a value for MaxNumberOfConnections, contact your SAP BASIS administrator to determine an appropriate value to maximize throughput without negatively affecting performance on the application server.
Support for multiple connections
By default the connector supports multiple-threads.

REWARD IF USEFULL

JMS multi thread best practise

Hi,
I would like to code a JMS layer that could be accessed by
a multi thread environment (a web app)
Is there any "Connection-Pool/DAO" equivalent design
pattern for JMS ?
Form what I know, connection are Thread Safe and Sessions
are not ...
Philippe

Many J2EE providers have their own JMS facades which provide pooling - so you could just use your container's JMS wrappers.
Another option, if you are inside a Servlet Engine, is to use Jencks which provides JMS & JDBC connection pooling as well as pooling of threads & message listeners & exception handling when consuming JMS messages.
e.g. here's inbound message consumption...
http://jencks.org/Message+Driven+POJOs
and here's outbound JMS (i.e. pooling when sending JMS messages etc)
http://jencks.org/Outbound+JMS
Jencks is basically a Spring based JCA container so it takes care of all the pooling for you as well as handling message inflow & outflow and can work with XA if you need it as well as local transactions.
James
http://logicblaze.com/

Oracle Multi-threaded libraries and Forte R3

Hello all,
I heard through the grapevine that it would be possible
to use Oracle 7.3 multi-threaded support with Forte 3.0G.
(thus making Load-Balancing obsolete in this case)
Has anyone given a try at this assumption ?
If yes, on what platform and what versions ?
Thanks,
Vincent Figari
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Hi,
It is available In R3.0.F.2 also. I tested it this release and it works
very well. But, you need to make a design pattern on it : A Oracle
Session can not be shared between several transactions throught threads.
So You need to manage a pool of DBSessions.
Hope this Helps,
Daniel Nguyen
Freelance Forte Consultant
Vincent R Figari wrote:
>
Hello all,
I heard through the grapevine that it would be possible
to use Oracle 7.3 multi-threaded support with Forte 3.0G.
(thus making Load-Balancing obsolete in this case)
Has anyone given a try at this assumption ?
If yes, on what platform and what versions ?
Thanks,
Vincent Figari
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Get completely free e-mail from Juno at http://www.juno.com
Or call Juno at (800) 654-JUNO [654-5866]
To unsubscribe, email '[email protected]' with
'unsubscribe forte-users' as the body of the message.
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'unsubscribe forte-users' as the body of the message.
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Multi-Thread application and common data

I try to make a multi-Thread application. All the Threads will update some common data.
How could I access the variable �VALUE� with the Thread in the following code:
public class Demo {
private static long VALUE;
public Demo(long SvId) {
VALUE = 0;
public static class makeThread extends Thread {
public void run() {
VALUE++;
public static long getVALUE() {
return VALUE;
The goal is to get the �VALUE� updated by the Thread with �getVALUE()�
Thanks for your reply
Benoit

That code is so wrong in so many ways......
I know you're just experimenting here, learning what can and can't be done with Threads, but bad habits start early, and get harder to kick as time goes on. I am going to give a little explanation here about what's wrong, and what's right.. If you're going to do anything serious though, please, read some books, and don't pick up bad habits.
Alright, The "answer" code. You don't use Thread.sleep() to wait for Threads to finish. That's just silly, use the join() method. It blocks until the threads execution is done. So if you have a whole bunch of threads in an array, and you want to start them up, and then do something once they finish. Do this.
for(int k=0; k<threads.length; k++) {
threads[k].start();
for(int k=0; k<threads.length; k++) {
threads[k].join();
System.out.println("All Threads Done");Now that's the simple problem. No tears there.
On to the java memory model. Here where the eye water starts flowing. The program you have written is not guarenteed to do what you expect it to do, that is, increment VALUE some amount of time and then print it out. The program is not "Thread Safe".
Problem 1) - Atomic Operations and Synchronization
Incrementing a 'long' is not an atomic operation via the JVM spec, icrementing an int is, so if you change the type of VALUE to an int you don't have to worry about corruption here. If a long is required, or any method with more then one operation that must complete without another thread entering. Then you must learn how to use the synchronized keyword.
Problem 2) - Visiblity
To get at this problem you have to understand low level computing terms. The variable VALUE will NOT be written out to main memory every time you increment it. It will be stored in the CPUs cache. If you have more then one CPU, and different CPUs get those threads you are starting up, one CPU won't know what the other is doing. You get memory overwrites, and nothing you expect. If you solve problem 1 by using a synchronized block, you also solve problem 2, because updating a variable under a lock will cause full visiblity of the change. However, there is another keyword in java.. "volatile".. A field modified with this keyword will always have it's changes visible.
This is a very short explaination, barely scratching the surface. I won't even go into performance issues here. If you want to know more. Here's the resources.
Doug Lea's book
http://java.sun.com/docs/books/cp/
Doug Lea's Site
http://g.cs.oswego.edu
-Spinoza

Analysis for Office support multi thread?

Does Analysis for Office support multi thread/core? If so, what verison? I tried searching around this site as well as note 1466118 - Hardware & Software requirements for Analysis, edition for MS Office but was unable to find an answer.
I am on an Intel dual cpu with hyper threading turned on so it essentially looks like 4 cores. When I execute an Analysis View, I rarely see the EXCEL.EXE process go above 25% CPU utilization. I have plenty of RAM and hard drive space.
64bit Windows 7
32bit Office 2010
AAO 1.3.5.2288
Thanks

I found the following info at:
Excel 2010 Performance: Performance and Limit Improvements
Large Data Sets and 64-bit Excel
The 64-bit version of Excel 2010 is not constrained to 2 GB of RAM like 32-bit applications. Therefore, 64-bit Excel 2010 enables users to create much larger workbooks. 64-bit Windows enables a larger addressable memory capacity, and 64-bit Excel is designed to take advantage of that capacity. For example, users are able to fill more of the grid with data than was possible in previous versions of Excel. As more RAM is added to the computer, Excel uses that additional memory, allows larger and larger workbooks, and scales with the amount of RAM available.
In addition, because 64-bit Excel enables larger data sets, both 32-bit and 64-bit Excel 2010 introduce improvements to common large data set tasks such as entering and filling down data, sorting, filtering, and copying and pasting data. Memory usage is also optimized to be more efficient, in both the 32-bit and 64-bit versions of Excel.
Multi-Core Processing
Additional investments were made to take advantage of multi-core processors and increase performance for routine tasks. Starting in Excel 2010, the following features use multi-core processors: saving a file, opening a file, refreshing a PivotTable (for external data sources, except OLAP and SharePoint), sorting a cell table, sorting a PivotTable, and auto-sizing a column.
For operations that involve reading and loading or writing data, such as opening a file, saving a file or refreshing data, splitting the operation into two processes increases performance speed. The first process gets the data, and the second process loads the data into the appropriate structure in memory or writes the data to a file. In this way, as soon as the first process beings reading a portion of data, the second process can immediately start loading or writing that data, while the first process continues to read the next portion of data. Previously, the first process had to finish reading all the data in a certain section before the second process could load that section of the data into memory or write the data to a file.

Enterprise User and Multi Thread Server

Hi,
We are going to build a system which uses a configuration:
10g2
Enterprise User
Multi Thread Server
Client apps accesses db over JDBC/SSL
Could some please share experience about issues regarding
using Enterprise User and Multi Thread Server ?
Is MTS transparant for Enterprise User authentication ?
Regards,
Cezary

If you build simpserv with -t, and set MIN and MAXDISPATCHTHREADS, you
should have an example of a multithreaded server.
Scott
Johan Philippe wrote:
>
We have been going to the documentation on multi-threading and contexting in servers
on Tuxedo 7.1.
And the impression so far is that apart from the function definitions there is
not much information around.
Didn't even find a simple example of a multi-threaded server in the Bea refs yet.
Does anyone know/have such an example?
And is anyone using multi-contexting in a server, because the limitation that
only server-dispatched
thread get a context puts quite a limitation on its usefullness.

Is ABAP multi-threading safe?

When implementing the Singleton design pattern in Java, we must use keyword synchronized with getInstance() method to ensure multi-threading safety, so that we can get the one and only instance.
What shall I do in ABAP? or just leave it alone? Would you help me find a example?
thanks and regards,
Davin,WANG

Hi Davin,
I do not understand fully what you are going to do in ABAP terms so I hope my comment will be of any value.
Multithreading may be achieved in ABAB by calling a function with the addition STARTING NEW TASK IN GROUP.... See my sample program for <a href="https://wiki.sdn.sap.com/wiki/display/Snippets/Easilyimplementparallelprocessinginonlineandbatchprocessing">Easily implement parallel processing in online and batch processing</a>
The second question may be solved by help of SAP lock concept. This is used primarily to secure a consistent database by not allowing two processes to change data at the same time. Chose a lock object of your choice and set at start of first instance. At end, remove the lock. Before creating the second instance, try so set the same lock. If you get a foreign lock error, you know the process is running.
See documentation on lock objects on how to lock/unlock.
Regards,
Clemens
Hope your internet connection is broken no longer so you can read this.

"Inconsistent cursor cache. Out of range cursor" error on dual processor multi thread

I have a C++ with Pro*C++ COM object running on a Win2000 OS on
a dual processor Middleware. The program is being called by a
service in a multi threaded way. An oracle error like ORA-2103
and SQL-02103 will be generated after running the program. We've
tried putting mutex on every SQL statement in Pro*C and it works
but the systems became very very slow. We concluded that the
error might be cause by a collision of threads accessing the
same Table or different tables having foreign constraints. This
is so because the error keeps coming from a statement accessing
Table A and following errors comes from a Table B having a
foreign key on Table A.
Our only solution now is to put Mutex on Statements accessing
same tables or tables with foreign constraints but this will
make our system run very very slow. I dont know if the problem
is in our Oracle Database because we already upgraded our system
from 8.1.6 to 8.1.7. The wierd thing on this is that the system
is running smoothly without oracle errors on a SINGLE PROCESSOR
Middleware. Hope you can give me any insights on this problem.

I have a C++ with Pro*C++ COM object running on a Win2000 OS on
a dual processor Middleware. The program is being called by a
service in a multi threaded way. An oracle error like ORA-2103
and SQL-02103 will be generated after running the program. We've
tried putting mutex on every SQL statement in Pro*C and it works
but the systems became very very slow. We concluded that the
error might be cause by a collision of threads accessing the
same Table or different tables having foreign constraints. This
is so because the error keeps coming from a statement accessing
Table A and following errors comes from a Table B having a
foreign key on Table A.
Our only solution now is to put Mutex on Statements accessing
same tables or tables with foreign constraints but this will
make our system run very very slow. I dont know if the problem
is in our Oracle Database because we already upgraded our system
from 8.1.6 to 8.1.7. The wierd thing on this is that the system
is running smoothly without oracle errors on a SINGLE PROCESSOR
Middleware. Hope you can give me any insights on this problem.

"SQL-02103: Inconsistent cursor cache." error on a dual processor multi threaded apps

I have a C++ with Pro*C++ COM object running on a Win2000 OS on
a dual processor Middleware. The program is being called by a
service in a multi threaded way. An oracle error like ORA-2103
and SQL-02103 will be generated after running the program. We've
tried putting mutex on every SQL statement in Pro*C and it works
but the systems became very very slow. We concluded that the
error might be cause by a collision of threads accessing the
same Table or different tables having foreign constraints. This
is so because the error keeps coming from a statement accessing
Table A and following errors comes from a Table B having a
foreign key on Table A.
Our only solution now is to put Mutex on Statements accessing
same tables or tables with foreign constraints but this will
make our system run very very slow. I dont know if the problem
is in our Oracle Database because we already upgraded our system
from 8.1.6 to 8.1.7. The wierd thing on this is that the system
is running smoothly without oracle errors on a SINGLE PROCESSOR
Middleware. Hope you can give me any insights on this problem.

I have a C++ with Pro*C++ COM object running on a Win2000 OS on
a dual processor Middleware. The program is being called by a
service in a multi threaded way. An oracle error like ORA-2103
and SQL-02103 will be generated after running the program. We've
tried putting mutex on every SQL statement in Pro*C and it works
but the systems became very very slow. We concluded that the
error might be cause by a collision of threads accessing the
same Table or different tables having foreign constraints. This
is so because the error keeps coming from a statement accessing
Table A and following errors comes from a Table B having a
foreign key on Table A.
Our only solution now is to put Mutex on Statements accessing
same tables or tables with foreign constraints but this will
make our system run very very slow. I dont know if the problem
is in our Oracle Database because we already upgraded our system
from 8.1.6 to 8.1.7. The wierd thing on this is that the system
is running smoothly without oracle errors on a SINGLE PROCESSOR
Middleware. Hope you can give me any insights on this problem.

"SQL-02103 Inconsistent cursor cache." error on dual processor multi threaded system

I have a C++ with Pro*C++ COM object running on a Win2000 OS on
a dual processor Middleware. The program is being called by a
service in a multi threaded way. An oracle error like ORA-2103
and SQL-02103 will be generated after running the program. We've
tried putting mutex on every SQL statement in Pro*C and it works
but the systems became very very slow. We concluded that the
error might be cause by a collision of threads accessing the
same Table or different tables having foreign constraints. This
is so because the error keeps coming from a statement accessing
Table A and following errors comes from a Table B having a
foreign key on Table A.
Our only solution now is to put Mutex on Statements accessing
same tables or tables with foreign constraints but this will
make our system run very very slow. I dont know if the problem
is in our Oracle Database because we already upgraded our system
from 8.1.6 to 8.1.7. The wierd thing on this is that the system
is running smoothly without oracle errors on a SINGLE PROCESSOR
Middleware. Hope you can give me any insights on this problem.

I have a C++ with Pro*C++ COM object running on a Win2000 OS on
a dual processor Middleware. The program is being called by a
service in a multi threaded way. An oracle error like ORA-2103
and SQL-02103 will be generated after running the program. We've
tried putting mutex on every SQL statement in Pro*C and it works
but the systems became very very slow. We concluded that the
error might be cause by a collision of threads accessing the
same Table or different tables having foreign constraints. This
is so because the error keeps coming from a statement accessing
Table A and following errors comes from a Table B having a
foreign key on Table A.
Our only solution now is to put Mutex on Statements accessing
same tables or tables with foreign constraints but this will
make our system run very very slow. I dont know if the problem
is in our Oracle Database because we already upgraded our system
from 8.1.6 to 8.1.7. The wierd thing on this is that the system
is running smoothly without oracle errors on a SINGLE PROCESSOR
Middleware. Hope you can give me any insights on this problem.

Multi thread D/B access design.

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