DRM Performance Optimization Memory Settings

Hello all,
We are using DRM 11.1.2.3.301. We would like to improve our DRM performance overall (not design related optimization). We have tried to find CPU, memory allocations related info in the documentation and could "not" any relevant info.
Could any of the experts please kindly forward info on where to find these tuning settings? Such as # of cpus, memory min, memory max allocation, etc.
I am sure these are embedded somewhere, appreciate if someone could point us to the relevant files, etc.
Thanks

Try to identify all the complex derived property parameters you have created and see if you can break them into pieces ( by creating seperate properties) to improve the performance ( this one time excersize will definitely end up with some improvement).
Also can you check if 11.1.2.3 has come up with Drm-diagnostics.exe( I haven't checked/tried it yet:-)) , if so please check that which will help you ( per Oracle ) to Identify properties which are causing performance issues and Compare derived property formulas to determine which is better performing.

Similar Messages

Performance optimization during database selection.

hi gurus,
pls any explain about this...
Strong knowledge of performance optimization during database selection.
regards,
praveen

Hi Praveen,
Performance Notes
1.Keep the Result Set Small
You should aim to keep the result set small. This reduces both the amount of memory used in the database system and the network load when transferring data to the application server. To reduce the size of your result sets, use the WHERE and HAVING clauses.
Using the WHERE Clause
Whenever you access a database table, you should use a WHERE clause in the corresponding Open SQL statement. Even if a program containing a SELECT statement with no WHERE clause performs well in tests, it may slow down rapidly in your production system, where the data volume increases daily. You should only dispense with the WHERE clause in exceptional cases where you really need the entire contents of the database table every time the statement is executed.
When you use the WHERE clause, the database system optimizes the access and only transfers the required data. You should never transfer unwanted data to the application server and then filter it using ABAP statements.
Using the HAVING Clause
After selecting the required lines in the WHERE clause, the system then processes the GROUP BY clause, if one exists, and summarizes the database lines selected. The HAVING clause allows you to restrict the grouped lines, and in particular, the aggregate expressions, by applying further conditions.
Effect
If you use the WHERE and HAVING clauses correctly:
     There are no more physical I/Os in the database than necessary
     No unwanted data is stored in the database cache (it could otherwise displace data that is actually required)
     The CPU usage of the database host is minimize
     The network load is reduced, since only the data that is required by the application is transferred to the application server.
Minimize the Amount of Data Transferred
Data is transferred between the database system and the application server in blocks. Each block is up to 32 KB in size (the precise size depends on your network communication hardware). Administration information is transported in the blocks as well as the data.
To minimize the network load, you should transfer as few blocks as possible. Open SQL allows you to do this as follows:
Restrict the Number of Lines
If you only want to read a certain number of lines in a SELECT statement, use the UP TO <n> ROWS addition in the FROM clause. This tells the database system only to transfer <n> lines back to the application server. This is more efficient than transferring more lines than necessary back to the application server and then discarding them in your ABAP program.
If you expect your WHERE clause to return a large number of duplicate entries, you can use the DISTINCT addition in the SELECT clause.
Restrict the Number of Columns
You should only read the columns from a database table that you actually need in the program. To do this, list the columns in the SELECT clause. Note here that the INTO CORRESPONDING FIELDS addition in the INTO clause is only efficient with large volumes of data, otherwise the runtime required to compare the names is too great. For small amounts of data, use a list of variables in the INTO clause.
Do not use * to select all columns unless you really need them. However, if you list individual columns, you may have to adjust the program if the structure of the database table is changed in the ABAP Dictionary. If you specify the database table dynamically, you must always read all of its columns.
Use Aggregate Functions
If you only want to use data for calculations, it is often more efficient to use the aggregate functions of the SELECT clause than to read the individual entries from the database and perform the calculations in the ABAP program.
Aggregate functions allow you to find out the number of values and find the sum, average, minimum, and maximum values.
Following an aggregate expression, only its result is transferred from the database.
Data Transfer when Changing Table Lines
When you use the UPDATE statement to change lines in the table, you should use the WHERE clause to specify the relevant lines, and then SET statements to change only the required columns.
When you use a work area to overwrite table lines, too much data is often transferred. Furthermore, this method requires an extra SELECT statement to fill the work area. Minimize the Number of Data Transfers
In every Open SQL statement, data is transferred between the application server and the database system. Furthermore, the database system has to construct or reopen the appropriate administration data for each database access. You can therefore minimize the load on the network and the database system by minimizing the number of times you access the database.
Multiple Operations Instead of Single Operations
When you change data using INSERT, UPDATE, and DELETE, use internal tables instead of single entries. If you read data using SELECT, it is worth using multiple operations if you want to process the data more than once, other wise, a simple select loop is more efficient.
Avoid Repeated Access
As a rule you should read a given set of data once only in your program, and using a single access. Avoid accessing the same data more than once (for example, SELECT before an UPDATE).
Avoid Nested SELECT Loops
A simple SELECT loop is a single database access whose result is passed to the ABAP program line by line. Nested SELECT loops mean that the number of accesses in the inner loop is multiplied by the number of accesses in the outer loop. You should therefore only use nested SELECT loops if the selection in the outer loop contains very few lines.
However, using combinations of data from different database tables is more the rule than the exception in the relational data model. You can use the following techniques to avoid nested SELECT statements:
ABAP Dictionary Views
You can define joins between database tables statically and systemwide as views in the ABAP Dictionary. ABAP Dictionary views can be used by all ABAP programs. One of their advantages is that fields that are common to both tables (join fields) are only transferred once from the database to the application server.
Views in the ABAP Dictionary are implemented as inner joins. If the inner table contains no lines that correspond to lines in the outer table, no data is transferred. This is not always the desired result. For example, when you read data from a text table, you want to include lines in the selection even if the corresponding text does not exist in the required language. If you want to include all of the data from the outer table, you can program a left outer join in ABAP.
The links between the tables in the view are created and optimized by the database system. Like database tables, you can buffer views on the application server. The same buffering rules apply to views as to tables. In other words, it is most appropriate for views that you use mostly to read data. This reduces the network load and the amount of physical I/O in the database.
Joins in the FROM Clause
You can read data from more than one database table in a single SELECT statement by using inner or left outer joins in the FROM clause.
The disadvantage of using joins is that redundant data is read from the hierarchically-superior table if there is a 1:N relationship between the outer and inner tables. This can considerably increase the amount of data transferred from the database to the application server. Therefore, when you program a join, you should ensure that the SELECT clause contains a list of only the columns that you really need. Furthermore, joins bypass the table buffer and read directly from the database. For this reason, you should use an ABAP Dictionary view instead of a join if you only want to read the data.
The runtime of a join statement is heavily dependent on the database optimizer, especially when it contains more than two database tables. However, joins are nearly always quicker than using nested SELECT statements.
Subqueries in the WHERE and HAVING Clauses
Another way of accessing more than one database table in the same Open SQL statement is to use subqueries in the WHERE or HAVING clause. The data from a subquery is not transferred to the application server. Instead, it is used to evaluate conditions in the database system. This is a simple and effective way of programming complex database operations.
Using Internal Tables
It is also possible to avoid nested SELECT loops by placing the selection from the outer loop in an internal table and then running the inner selection once only using the FOR ALL ENTRIES addition. This technique stems from the time before joins were allowed in the FROM clause. On the other hand, it does prevent redundant data from being transferred from the database.
Using a Cursor to Read Data
A further method is to decouple the INTO clause from the SELECT statement by opening a cursor using OPEN CURSOR and reading data line by line using FETCH NEXT CURSOR. You must open a new cursor for each nested loop. In this case, you must ensure yourself that the correct lines are read from the database tables in the correct order. This usually requires a foreign key relationship between the database tables, and that they are sorted by the foreign key. Minimize the Search Overhead
You minimize the size of the result set by using the WHERE and HAVING clauses. To increase the efficiency of these clauses, you should formulate them to fit with the database table indexes.
Database Indexes
Indexes speed up data selection from the database. They consist of selected fields of a table, of which a copy is then made in sorted order. If you specify the index fields correctly in a condition in the WHERE or HAVING clause, the system only searches part of the index (index range scan).
The primary index is always created automatically in the R/3 System. It consists of the primary key fields of the database table. This means that for each combination of fields in the index, there is a maximum of one line in the table. This kind of index is also known as UNIQUE.
If you cannot use the primary index to determine the result set because, for example, none of the primary index fields occur in the WHERE or HAVING clause, the system searches through the entire table (full table scan). For this case, you can create secondary indexes, which can restrict the number of table entries searched to form the result set.
You specify the fields of secondary indexes using the ABAP Dictionary. You can also determine whether the index is unique or not. However, you should not create secondary indexes to cover all possible combinations of fields.
Only create one if you select data by fields that are not contained in another index, and the performance is very poor. Furthermore, you should only create secondary indexes for database tables from which you mainly read, since indexes have to be updated each time the database table is changed. As a rule, secondary indexes should not contain more than four fields, and you should not have more than five indexes for a single database table.
If a table has more than five indexes, you run the risk of the optimizer choosing the wrong one for a particular operation. For this reason, you should avoid indexes with overlapping contents.
Secondary indexes should contain columns that you use frequently in a selection, and that are as highly selective as possible. The fewer table entries that can be selected by a certain column, the higher that columns selectivity. Place the most selective fields at the beginning of the index. Your secondary index should be so selective that each index entry corresponds to at most five percent of the table entries. If this is not the case, it is not worth creating the index. You should also avoid creating indexes for fields that are not always filled, where their value is initial for most entries in the table.
If all of the columns in the SELECT clause are contained in the index, the system does not have to search the actual table data after reading from the index. If you have a SELECT clause with very few columns, you can improve performance dramatically by including these columns in a secondary index.
Formulating Conditions for Indexes
You should bear in mind the following when formulating conditions for the WHERE and HAVING clauses so that the system can use a database index and does not have to use a full table scan.
Check for Equality and Link Using AND
The database index search is particularly efficient if you check all index fields for equality (= or EQ) and link the expressions using AND.
Use Positive Conditions
The database system only supports queries that describe the result in positive terms, for example, EQ or LIKE. It does not support negative expressions like NE or NOT LIKE.
If possible, avoid using the NOT operator in the WHERE clause, because it is not supported by database indexes; invert the logical expression instead.
Using OR
The optimizer usually stops working when an OR expression occurs in the condition. This means that the columns checked using OR are not included in the index search. An exception to this are OR expressions at the outside of conditions. You should try to reformulate conditions that apply OR expressions to columns relevant to the index, for example, into an IN condition.
Using Part of the Index
If you construct an index from several columns, the system can still use it even if you only specify a few of the columns in a condition. However, in this case, the sequence of the columns in the index is important. A column can only be used in the index search if all of the columns before it in the index definition have also been specified in the condition.
Checking for Null Values
The IS NULL condition can cause problems with indexes. Some database systems do not store null values in the index structure. Consequently, this field cannot be used in the index.
Avoid Complex Conditions
Avoid complex conditions, since the statements have to be broken down into their individual components by the database system.
Reduce the Database Load
Unlike application servers and presentation servers, there is only one database server in your system. You should therefore aim to reduce the database load as much as possible. You can use the following methods:
Buffer Tables on the Application Server
You can considerably reduce the time required to access data by buffering it in the application server table buffer. Reading a single entry from table T001 can take between 8 and 600 milliseconds, while reading it from the table buffer takes 0.2 - 1 milliseconds.
Whether a table can be buffered or not depends its technical attributes in the ABAP Dictionary. There are three buffering types:
     Resident buffering (100%) The first time the table is accessed, its entire contents are loaded in the table buffer.
     Generic buffering In this case, you need to specify a generic key (some of the key fields) in the technical settings of the table in the ABAP Dictionary. The table contents are then divided into generic areas. When you access data with one of the generic keys, the whole generic area is loaded into the table buffer. Client-specific tables are often buffered generically by client.
     Partial buffering (single entry) Only single entries are read from the database and stored in the table buffer.
When you read from buffered tables, the following happens:
1.     An ABAP program requests data from a buffered table.
2.     The ABAP processor interprets the Open SQL statement. If the table is defined as a buffered table in the ABAP Dictionary, the ABAP processor checks in the local buffer on the application server to see if the table (or part of it) has already been buffered.
3.     If the table has not yet been buffered, the request is passed on to the database. If the data exists in the buffer, it is sent to the program.
4.     The database server passes the data to the application server, which places it in the table buffer.
5.     The data is passed to the program.
When you change a buffered table, the following happens:
1.     The database table is changed and the buffer on the application server is updated. The database interface logs the update statement in the table DDLOG. If the system has more than one application server, the buffer on the other servers is not updated at once.
2.     All application servers periodically read the contents of table DDLOG, and delete the corresponding contents from their buffers where necessary. The granularity depends on the buffering type. The table buffers in a distributed system are generally synchronized every 60 seconds (parameter: rsdisp/bufreftime).
3.     Within this period, users on non-synchronized application servers will read old data. The data is not recognized as obsolete until the next buffer synchronization. The next time it is accessed, it is re-read from the database.
You should buffer the following types of tables:
     Tables that are read very frequently
     Tables that are changed very infrequently
     Relatively small tables (few lines, few columns, or short columns)
     Tables where delayed update is acceptable.
Once you have buffered a table, take care not to use any Open SQL statements that bypass the buffer.
The SELECT statement bypasses the buffer when you use any of the following:
     The BYPASSING BUFFER addition in the FROM clause
     The DISTINCT addition in the SELECT clause
     Aggregate expressions in the SELECT clause
     Joins in the FROM clause
     The IS NULL condition in the WHERE clause
     Subqueries in the WHERE clause
     The ORDER BY clause
     The GROUP BY clause
     The FOR UPDATE addition
Furthermore, all Native SQL statements bypass the buffer.
Avoid Reading Data Repeatedly
If you avoid reading the same data repeatedly, you both reduce the number of database accesses and reduce the load on the database. Furthermore, a "dirty read" may occur with database tables other than Oracle. This means that the second time you read data from a database table, it may be different from the data read the first time. To ensure that the data in your program is consistent, you should read it once only and then store it in an internal table.
Sort Data in Your ABAP Programs
The ORDER BY clause in the SELECT statement is not necessarily optimized by the database system or executed with the correct index. This can result in increased runtime costs. You should only use ORDER BY if the database sort uses the same index with which the table is read. To find out which index the system uses, use SQL Trace in the ABAP Workbench Performance Trace. If the indexes are not the same, it is more efficient to read the data into an internal table or extract and sort it in the ABAP program using the SORT statement.
Use Logical Databases
SAP supplies logical databases for all applications. A logical database is an ABAP program that decouples Open SQL statements from application programs. They are optimized for the best possible database performance. However, it is important that you use the right logical database. The hierarchy of the data you want to read must reflect the structure of the logical database, otherwise, they can have a negative effect on performance. For example, if you want to read data from a table right at the bottom of the hierarchy of the logical database, it has to read at least the key fields of all tables above it in the hierarchy. In this case, it is more efficient to use a SELECT statement.
Work Processes
Work processes execute the individual dialog steps in R/3 applications. The next two sections describe firstly the structure of a work process, and secondly the different types of work process in the R/3 System.
Structure of a Work Process
Work processes execute the dialog steps of application programs. They are components of an application server. The following diagram shows the components of a work process:
Each work process contains two software processors and a database interface.
Screen Processor
In R/3 application programming, there is a difference between user interaction and processing logic. From a programming point of view, user interaction is controlled by screens. As well as the actual input mask, a screen also consists of flow logic. The screen flow logic controls a large part of the user interaction. The R/3 Basis system contains a special language for programming screen flow logic. The screen processor executes the screen flow logic. Via the dispatcher, it takes over the responsibility for communication between the work process and the SAPgui, calls modules in the flow logic, and ensures that the field contents are transferred from the screen to the flow logic.
ABAP Processor
The actual processing logic of an application program is written in ABAP - SAPs own programming language. The ABAP processor executes the processing logic of the application program, and communicates with the database interface. The screen processor tells the ABAP processor which module of the screen flow logic should be processed next. The following screen illustrates the interaction between the screen and the ABAP processors when an application program is running.
Database Interface
The database interface provides the following services:
     Establishing and terminating connections between the work process and the database.
     Access to database tables
     Access to R/3 Repository objects (ABAP programs, screens and so on)
     Access to catalog information (ABAP Dictionary)
     Controlling transactions (commit and rollback handling)
     Table buffer administration on the application server.
The following diagram shows the individual components of the database interface:
The diagram shows that there are two different ways of accessing databases: Open SQL and Native SQL.
Open SQL statements are a subset of Standard SQL that is fully integrated in ABAP. They allow you to access data irrespective of the database system that the R/3 installation is using. Open SQL consists of the Data Manipulation Language (DML) part of Standard SQL; in other words, it allows you to read (SELECT) and change (INSERT, UPDATE, DELETE) data. The tasks of the Data Definition Language (DDL) and Data Control Language (DCL) parts of Standard SQL are performed in the R/3 System by the ABAP Dictionary and the authorization system. These provide a unified range of functions, irrespective of database, and also contain functions beyond those offered by the various database systems.
Open SQL also goes beyond Standard SQL to provide statements that, in conjunction with other ABAP constructions, can simplify or speed up database access. It also allows you to buffer certain tables on the application server, saving excessive database access. In this case, the database interface is responsible for comparing the buffer with the database. Buffers are partly stored in the working memory of the current work process, and partly in the shared memory for all work processes on an application server. Where an R/3 System is distributed across more than one application server, the data in the various buffers is synchronized at set intervals by the buffer management. When buffering the database, you must remember that data in the buffer is not always up to date. For this reason, you should only use the buffer for data which does not often change.
Native SQL is only loosely integrated into ABAP, and allows access to all of the functions contained in the programming interface of the respective database system. Unlike Open SQL statements, Native SQL statements are not checked and converted, but instead are sent directly to the database system. Programs that use Native SQL are specific to the database system for which they were written. R/3 applications contain as little Native SQL as possible. In fact, it is only used in a few Basis components (for example, to create or change table definitions in the ABAP Dictionary).
The database-dependent layer in the diagram serves to hide the differences between database systems from the rest of the database interface. You choose the appropriate layer when you install the Basis system. Thanks to the standardization of SQL, the differences in the syntax of statements are very slight. However, the semantics and behavior of the statements have not been fully standardized, and the differences in these areas can be greater. When you use Native SQL, the function of the database-dependent layer is minimal.
Types of Work Process
Although all work processes contain the components described above, they can still be divided into different types. The type of a work process determines the kind of task for which it is responsible in the application server. It does not specify a particular set of technical attributes. The individual tasks are distributed to the work processes by the dispatcher.
Before you start your R/3 System, you determine how many work processes it will have, and what their types will be. The dispatcher starts the work processes and only assigns them tasks that correspond to their type. This means that you can distribute work process types to optimize the use of the resources on your application servers.
The following diagram shows again the structure of an application server, but this time, includes the various possible work process types:
The various work processes are described briefly below. Other parts of this documentation describe the individual components of the application server and the R/3 System in more detail.
Dialog Work Process
Dialog work processes deal with requests from an active user to execute dialog steps.
Update Work Process
Update work processes execute database update requests. Update requests are part of an SAP LUW that bundle the database operations resulting from the dialog in a database LUW for processing in the background.
Background Work Process
Background work processes process programs that can be executed without user interaction (background jobs).
Enqueue Work Process
The enqueue work process administers a lock table in the shared memory area. The lock table contains the logical database locks for the R/3 System and is an important part of the SAP LUW concept. In an R/3 System, you may only have one lock table. You may therefore also only have one application server with enqueue work processes.
Spool Work Process
The spool work process passes sequential datasets to a printer or to optical archiving. Each application server may contain several spool work process.
The services offered by an application server are determined by the types of its work processes. One application server may, of course, have more than one function. For example, it may be both a dialog server and the enqueue server, if it has several dialog work processes and an enqueue work process.
You can use the system administration functions to switch a work process between dialog and background modes while the system is still running. This allows you, for example, to switch an R/3 System between day and night operation, where you have more dialog than background work processes during the day, and the other way around during the night.
ABAP Application Server
R/3 programs run on application servers. They are an important component of the R/3 System. The following sections describe application servers in more detail.
Structure of an ABAP Application Server
The application layer of an R/3 System is made up of the application servers and the message server. Application programs in an R/3 System are run on application servers. The application servers communicate with the presentation components, the database, and also with each other, using the message server.
The following diagram shows the structure of an application server:
The individual components are:
Work Processes
An application server contains work processes, which are components that can run an application. Work processes are components that are able to execute an application (that is, one dialog step each). Each work process is linked to a memory area containing the context of the application being run. The context contains the current data for the application program. This needs to be available in each dialog step. Further information about the different types of work process is contained later on in this documentation.
Dispatcher
Each application server contains a dispatcher. The dispatcher is the link between the work processes and the users logged onto the application server. Its task is to receive requests for dialog steps from the SAP GUI and direct them to a free work process. In the same way, it directs screen output resulting from the dialog step back to the appropriate user.
Gateway
Each application server contains a gateway. This is the interface for the R/3 communication protocols (RFC, CPI/C). It can communicate with other application servers in the same R/3 System, with other R/3 Systems, with R/2 Systems, or with non-SAP systems.
The application server structure as described here aids the performance and scalability of the entire R/3 System. The fixed number of work processes and dispatching of dialog steps leads to optimal memory use, since it means that certain components and the memory areas of a work process are application-independent and reusable. The fact that the individual work processes work independently makes them suitable for a multi-processor architecture. The methods used in the dispatcher to distribute tasks to work processes are discussed more closely in the section Dispatching Dialog Steps.
Shared Memory
All of the work processes on an application server use a common main memory area called shared memory to save contexts or to buffer constant data locally.
The resources that all work processes use (such as programs and table contents) are contained in shared memory. Memory management in the R/3 System ensures that the work processes always address the correct context, that is the data relevant to the current state of the program that is running. A mapping process projects the required context for a dialog step from shared memory into the address of the relevant work process. This reduces the actual copying to a minimum.
Local buffering of data in the shared memory of the application server reduces the number of database reads required. This reduces access times for application programs considerably. For optimal use of the buffer, you can concentrate individual applications (financial accounting, logistics, human resources) into separate application server groups.
Database Connection
When you start up an R/3 System, each application server registers its work processes with the database layer, and receives a single dedicated channel for each. While the system is running, each work process is a user (client) of the database system (server). You cannot change the work process registration while the system is running. Neither can you reassign a database channel from one work process to another. For this reason, a work process can only make database changes within a single database logical unit of work (LUW). A database LUW is an inseparable sequence of database operations. This has important consequences for the programming model explained below.
Dispatching Dialog Steps
The number of users logged onto an application server is often many times greater than the number of available work processes. Furthermore, it is not restricted by the R/3 system architecture. Furthermore, each user can run several applications at once. The dispatcher has the important task of distributing all dialog steps among the work processes on the application server.
The following diagram is an example of how this might happen:
       1.      The dispatcher receives the request to execute a dialog step from user 1 and directs it to work process 1, which happens to be free. The work process addresses the context of the application program (in shared memory) and executes the dialog step. It then becomes free again.
       2.      The dispatcher receives the request to execute a dialog step from user 2 and directs it to work process 1, which is now free again. The work process executes the dialog step as in step 1.
       3.      While work process 1 is still working, the dispatcher receives a further request from user 1 and directs it to work process 2, which is free.
       4.      After work processes 1 and 2 have finished processing their dialog steps, the dispatcher receives another request from user 1 and directs it to work process 1, which is free again.
       5.      While work process 1 is still working, the dispatcher receives a further request from user 2 and directs it to work process 2, which is free.
From this example, we can see that:
        A dialog step from a program is assigned to a single work process for execution.
        The individual dialog steps of a program can be executed on different work processes, and the program context must be addressed for each new work process.
        A work process can execute dialog steps of different programs from different users.
The example does not show that the dispatcher tries to distribute the requests to the work processes such that the same work process is used as often as possible for the successive dialog steps in an application. This is useful, since it saves the program context having to be addressed each time a dialog step is executed.
Dispatching and the Programming Model
The separation of application and presentation layer made it necessary to split up application programs into dialog steps. This, and the fact that dialog steps are dispatched to individual work processes, has had important consequences for the programming model.
As mentioned above, a work process can only make database changes within a single database logical unit of work (LUW). A database LUW is an inseparable sequence of database operations. The contents of the database must be consistent at its beginning and end. The beginning and end of a database LUW are defined by a commit command to the database system (database commit). During a database LUW, that is, between two database commits, the database system itself ensures consistency within the database. In other words, it takes over tasks such as locking database entries while they are being edited, or restoring the old data (rollback) if a step terminates in an error.
A typical SAP application program extends over several screens and the corresponding dialog steps. The user requests database changes on the individual screens that should lead to the database being consistent once the screens have all been processed. However, the individual dialog steps run on different work processes, and a single work process can process dialog steps from other applications. It is clear that two or more independent applications whose dialog steps happen to be processed on the same work process cannot be allowed to work with the same database LUW.
Consequently, a work process must open a separate database LUW for each dialog step. The work process sends a commit command (database commit) to the database at the end of each dialog step in which it makes database changes. These commit commands are called implicit database commits, since they are not explicitly written into the application program.
These implicit database commits mean that a database LUW can be kept open for a maximum of one dialog step. This leads to a considerable reduction in database load, serialization, and deadlocks, and enables a large number of users to use the same system.
However, the question now arises of how this method (1 dialog step = 1 database LUW) can be reconciled with the demand to make commits and rollbacks dependent on the logical flow of the application program instead of the technical distribution of dialog steps. Database update requests that depend on one another form logical units in the program that extend over more than one dialog step. The database changes associated with these logical units must be executed together and must also be able to be undone together.
The SAP programming model contains a series of bundling techniques that allow you to group database updates together in logical units. The section of an R/3 application program that bundles a set of logically-associated database operations is called an SAP LUW. Unlike a database LUW, a SAP LUW includes all of the dialog steps in a logical unit, including the database update.
Happy Reading...
shibu

PI 7.1 memory settings ?

Hi Guys,
I have installled PI 7.1 and i am looking for ABAP and Java memory settings. I am facing lot of short dump errors on the ABAP side when installing the support packs.
I have restored the image back and now i want to set the memory parameters on both the ABAP and Java before i start patching them again.
any help or links for the memory settings on both the ABAP and Java would be a great help.
Thanks,
Srini

Hi,Charles
PI7.1 default JVM heap size is 2GB.
You can check your Haep memory available in the Web MMC.
http://<yourhostname>:5<SIDnumber>13
Select your Java server node, you can check the memory.
Please checked the following notes,
note 894509 - XI Performance Check
note 1060264 - PI Troubleshooting Guide 7.1
note 1248926 - AS Java VM Parameters for NetWeaver 7.1 based products
Best Regards,
Michikuni

Which "Optimize Memory For" setting is best ?

I don't understand this..Or I think I've used it wrong..please help?
By default, Premiere Pro renders video using the maximum number of available processors, up to 16. However, some sequences, such as those containing high-resolution source video or still images, require large amounts of memory for the simultaneous rendering of multiple frames. These sequences can force Premiere Pro to cancel rendering and to give a Low Memory Warning alert. In these cases, you can maximize the available memory by changing the rendering optimization preference from Performance to Memory. Change this preference back to Performance when rendering no longer requires memory optimization.
Select Edit > Preferences, and select Memory in the Preferences dialog box.
In the drop-down list next to Optimize Rendering For, select Memory.
Click OK, close Premiere Pro, and reopen the project for the new preference to take effect.
Does setting to MEMORY only benefit lower end systems with bottlenecks, or do you use this settting on higher end machines too?
I've always had mine set to MEMORY because I thought it would make better use of the memory. Now I have a higher end machine with 16GB of ram. And I just read a thread where someone said set it to peroformance if you want to see more CPU/RAM utilization..so now I'm confused.... Do I set it to PERFORMANCE or MEMORY w/ 16GB of ram (core i7 2600k @ 4.2ghz)? Also if you could explain why. Thanks!

Why would low-end RAM affect the Performance Setting (vs. Memory). It seems like the Memory setting would rely more heavily on RAM (where I have no problems).
For what it's worth, this is a dedicated "high end" editing machine, and the RAM was top performance/top dollar when purchased.
"I believe setting the optimise to Memory will slow down the render speed to acceptable levels" I would like to know if this is in fact really the case (which would suggest optimize to Memory is a "slower" setting than optimize to Memory).
I am seeing this problem in CS6 with only HD footage after editing an entire feature with CS4 in 4K (.r3d) without any issues. Seems very weird.

SQL Server Max Memory Settings

Hi,
I'd like to check if SQL Server will consume memory more than the configured MAX Memory settings? And if so when does SQL consume that and how much would it consume.
Regards,
Jay

Hi,
I'd like to check if SQL Server will consume memory more than the configured MAX Memory settings? And if so when does SQL consume that and how much would it consume.
Hi
Can you please tell us what is version and edition of SQL Server here. If it is 2012 its little difficult to reporduce your scenario where SQL Server 2012 will take more than max server memory setting because lots of features which use to take memory
outside buffer pool before SQL 2012 are now changed to take memory from buffer pool. Also quite lot depends on whether system is 32 bit or 64 bit
For SQL Server versions below 2012(not SS2000) you might get lucky with following (taken from
Here)
1. COM Objects
2. SQL Server CLR
3. Memory allocated by Linked Server OLEDB Providers and third party DLL’s loaded in SQL Server process
4. Extended Stored Procedures:
5. Network Packets
6. Memory consumed by memory managers. If the memory request is greater than 8 KB and needs contiguous allocation.
7. Backup
If you heavily use above features you might see SQL Server memory utilization crossing above max server memory setting. Of all above SQLCLR and extended stored procs would be my bet. If you use them heavily you might see what you want to. Extended
stored proc has performance issues so use it on your own risk. Use below query to check SQL server memory utilization( works from SS 2008 and above)
select
(physical_memory_in_use_kb/1024)Memory_usedby_Sqlserver_MB,
(locked_page_allocations_kb/1024 )Locked_pages_used_Sqlserver_MB,
(total_virtual_address_space_kb/1024 )Total_VAS_in_MB,
process_physical_memory_low,
process_virtual_memory_low
from sys. dm_os_process_memory
Please mark this reply as answer if it solved your issue or vote as helpful if it helped so that other forum members can benefit from it.
My TechNet Wiki Articles

Linux memory settings

We installed the suite on a linux server in a managed configuration (AdminServer, soa_server1, bam_server1).
At first we didnot change the memory settings so all three process ran with memory settings:
-Xms512m -Xmx1024m -XX:PermSize=128m -XX:MaxPermSize=512m
With these settings the suite ran OK at first but gradually the performance detoriated.
Using jconsole I looked at the memory consumption of the processes and the soa_server1 was using up all memory while the AdminServer and bam_server1 had plenty of memory.
I changed the memory setting specific to the servers:
AdminServer, bam_server1
-Xms768m -Xmx768m -XX:PermSize=128m -XX:MaxPermSize=256m
soa_server1
-Xms1536m -Xmx1536m -XX:PermSize=128m -XX:MaxPermSize=512m
The process have been running stable upto now.
The server:
OS: oracle enterprise server release 4 update 7
Cpu: 4*E7340 @ 2.4 Ghz
Ram: 8 Gb
Any other experiences with memory settings on linux and/or using a single server setup vs the shared configuration?
Gr,
Gert Jan Kersten

About rebuilding kernel
on linux 7.0 :
1. Try to look at file /usr/src/linux/include/asm/shmparam.h
Update parameters SHMMAX, SHMMIN, SHMMNI, SHMSEG.
SHMMAX is set to 50% of RAM
SHMMIN 1
SHMMNI 100
SHMSEG 10
2. edit file /usr/src/linux/include/linux/sem.h
and set param
SEMMSL 250
SEMOPM 100
SEMVMX 32767
3. After then you must configure kernel, and set modules
and drivers when you need.
>cd /usr/src/linux
>make xconfig
4. Save configure.
5. >cd /usr/src/linux
>make clean
>make dep
>make bzImage
6. Command make bzImage create new kernel in directory
/usr/src/linux/arch/i386/boot
there is file bzImage
7. copy new kernel to /boot directory
8. you must edit /etc/lilo.cfg and add new record for
new kernel.
9. write lilo to disk
>cd /etc
> lilo -c
10. Be shure that you can boot old kernel !!!!!
11. restart.
12. After correct reboot new kernel you can see to the
/proc/sys/kernel/shmmax
there is parameter about max shared memory.
on Linux 7.1
is different file path and name for edit.
/usr/src/linux-2.4/include/linux/sem.h
/usr/src/linux-2.4/include/linux/shm.h
Hi.

K8N SLI FI Memory Settings Help

I have 4 x DDR400 in Dual Channel mode. Datasheet below: -
http://www.hynix.com/datasheet/pdf/dram/HY5DU124(8,16)22C(L)TP(Rev1.3).pdf
I previously had an ASUS A8N Board with no stability problems until i tried to add a sound blaster live card and had issues with its handling of interrupts. Seem to be a problem with the Asus Board as a tried another sound card and issues were same. Couldn't separate Int for card from display (tried different PCI slots).
I recent bought a K8N SLI FI motherboard (updated bios to 1.60) and have nothing but stability problems since. System continually freezes at intermitant intervals. (I note the K8N as different DRAM page in bios to A8N). I am using a 600W Shaw PSU.
I note with 1.6 bios the auto memory settings don't seem to match the memory sheet enclosed.
i.e. Memory voltage is 2.5 (2.4x) according to the system monitor, not 2.6 as required. Tcl, etc seems to differ also.
I have AMD 3500+ CPU.
Can you please help and provide correct Tcl, Tras, Trp,Trrd, Trc, Trfc, Trwrt, Twr, Twtr, Tref settings and advise if any setting changes to User Config mode please.
I am not interested in over-clocking, i just want a reliable system.
Cheers for any help

I did that about the same time you posted dude, thks.
Unfortunately, my system still keeps freezing in WinXP (32) and is as useful as t.ts on a bull.
I currently have the auto setting with the main timing showing 3-3-3-8 at boot time.
Voltage core-centre shows within spec 2.6x for ram and 1.5x for cpu.
I had to beef the cpu voltage by 3.3% setting to get 1.5x as it was showing 1.4x in the health report.
I am using latest nVidia driver 6.70 package and have a force 6600 card with latest drivers.
Never had any stablity problems in the ASUS A8N until i stuck an extra sound card in there (both SB Live and CMI3784) and then thing would reboot withever 2nd sound card drivers loaded. Pinned it too problems with the IRQ allocation and figured a design problem.
Bought the K8N SLI FI board and have nothing but random freeze problems.
No answers from MSI, great!
Apart from irq sharing problems on a8n, that board limited the DDR to 333 and not 400 when in dual channel mode.
What settings do i use to archieve timings for 333 on this board?
I am trying to use the board for video editing work and prefer reliability over performance.
Thanks all for any help

Memory settings (MS6380)

Hello,
I got a quick question about my memory settings.
I have got 512MB PC2100 DDR (Samsung) and a MS 6380 KT266.
In the bench-program CPU-Z the memory tab states:
Frequency 200MHz, CAS# Latency 2clocks, RAS to CAS 2clocks, RAS Precharge 2clocks, Cycle Time(Tras) 5clocks.
Shouldn't the frequency be 266 MHz ?
This are my RAM related BIOS settings:
Configured SDRAM Timing by : SPD
SDRAM Frequenty : HCLK-33
SDRAM CAS # Latency : 2.5
SDRAM Bank Interleave : disabled
SDRAM 1T Command : disabled
If 200Mhz is normal, could I change these settings anyway to gain performance ?
Thanks in advance.

Quote
Originally posted by Sinnet6380
Does anyone know what "SDRAM Bank Interleave" and "SDRAM 1T Command" do ?
I couldn't find their function anywhere in the manual and on some sites.
They're both disabled now.
Hi, SDRAM Bank Interleave can be analogous to RAID-0 your RAM into 2-way or 4-way, to improve RAM performance.
SDRAM 1T Command is to enable SDRAM signal controller to run at 1T rate. When disabled, it's at 2T rate.

Memory settings for WLS server

Hi
In my production server for weblogic the memory settings is set to
MEM_ARGS=-Xms64m -Xmx64m
I have a 4GB of RAM in my server,
If I increase the MEM_ARGS parm will it give a better performance.?
what will be a better number to go with instead of 64M
Please advise
Thanks
DN

Rob
Thanks for the answer ,
I dont have much applications running on this PC other than SQL server.
SQL server is configured to take a mximum of 2GB I believe.
You suggest to change the minimum and maximum to 512 right?
what does the initial part(-XX:MaxPermSize=128m ) of the following line means?
MEM_ARGS="-XX:MaxPermSize=128m -Xms512m -Xmx512m"
Thanks again
DN
Rob Woollen <[email protected]> wrote:
DN wrote:
Hi
In my production server for weblogic the memory settings is set to
MEM_ARGS=-Xms64m -Xmx64m
I have a 4GB of RAM in my server,
If I increase the MEM_ARGS parm will it give a better performance.?Most likely. Is anything else running on this machine? You have a lot
of free memory, and in general larger heaps do help minimize time spent
in garbage collection.
I'd suggest reading
http://edocs.bea.com/wljrockit/docs81/tuning/basic.html#999276
what will be a better number to go with instead of 64MI'd bump it up to 512MB and tune from there.
-- Rob
Please advise
Thanks
DN

P7N SLI Plat. and memory settings

Hey guy! Again, great forums! Thanks for all the help. Noob question coming up.
I have a couple of questions about the P7N SLI Platinum and memory settings. Oh, before I begin, let me say that I bought this stuff as part of deal, and ended up with the 1066 ram.
I have a few options under my belt, and I don't know which would be the best. I'm also looking for some kind of software to test RAM speeds; test between MHZ and timings performance? Does Sandra do that? Anyone know of any other programs?
Some recommend that I run 1:1 FSB:RAM ratio (looks like the most favored), but some say some boards can do better if everything is running as fast as it can, and not to worry about the ratio.
So which is it with the P7N, which is a 750i chipset?
Here's the rest of the situation:
I have a set of 2x2GB DDR2 1066 5-5-5-15; 2T @2.1v.
I have a Q6600 2.4GHz @ 3.0Ghz (1333x9) OC-ed.
I have run this memory at 1066 on this board with no hitches (overclocking the board essentially, but it handles it like a champ)
I can also run it at 800; but I have not tried tighter timings on this.
I can run it at 667 and lower timings to 4-4-4-14; 1T with no problems (so far). This gives me a 1:1 ratio as well.
This is what I am running right now.
What should I do with this board and this CPU? Should I keep 1:1 and tighten timings? I don't know if I can go below 4-4-4-14; I haven't tried yet.
Or should I run at 1066 with the stock timings?
I have been reading, but I keep hearing conflicting information (though I will admit, it's hard to find info that is very recent; articles varied from '06-'08) Some say 1:1 is best, others say that it's not necessary these days, with modern boards?
The different performance preferences also seem to vary from chipset to chipset? Is that correct?
Thank You very much for helping a lost noob!

Remus this is no bulldash, i had two 1GB DDR2 1066 cl5 1.8 volt and i sold it on ebay a week ago for £21.00 . i used it on my p6 which would take only ddr2 800 (it ran at 800mhz 1.8 volt but these were not suitable at all in terms of stability) and also on my asus which would take ddr21066 but only after overclocking fsb but keeping the default voltage at 1.8volt. those who say ddr2 1066 1.8 volt does not exist should review their comments. i believe crucial does ddr2 1066 1.8 volt and also ddr2 1066 2.1 volt
here is the proof of ebay
http://s240.photobucket.com/albums/ff177/kourosh22/?action=view&current=ScreenShot077.jpg
http://s240.photobucket.com/albums/ff177/kourosh22/?action=view&current=ScreenShot076.jpg
a memory has an oscillator and we refer to them as 800mhz or 1066mhz. because memory sticks have 240 terminals or pins for transfer of data in order to be able to increase the rate of transfer not only the oscillator speed has to be increased other parameters has to change.
DDR2 1066 1.8 volt is a memory which it's oscillator oscillate at 1066mhz when 1.8 volt is applied to, it's terminals with cas latency 5 or Cl5.
DDR2 1066 2.1 or 2.2 volt is a memory which it's oscillator oscillate at 1066mhz when 2.1 or 2,2 voltage is applied to it's terminals otherwise it will oscillate at 800mhz. these kind of DDR2 1066 are referred to as DRR2 800 overclocked.

How to configure the memory settings based on the number of VSAs for Cisco service control Subscriber Manager?

Hey Good day to all,
please help with this; when installing the Service Control Management Suite Subscriber Manager scms-sm, and at the secound step where you have to determine the system memory settings, there are several attributes to be considered:
the maximum number of the subscribers
with or without qouta manager
number of VSAs used
so, my question is about the memory configuration parameters versus the number of VSAs used, since you must multiply with certain values, set already on a table on the Cisco website, but as shown in the example under the table these values are multiplied to all the attributes except that the example dosn't show the value of the temp-size memory;
so please confirm this to me:
the temporary memory size "temp_size" is not related to the number of VSAs implemented!
this is a screen shot from Cisco website:
thank you in advance for helping

Hi Tessitori,
The best way to cache, index and query that amount of data in Coherence is to use a number of stand alone JVMs (i.e. com.tangosol.net.DefaultCacheServer s) to 'manage' the data. Then access (query) that cache from your application servers instances. For an indexing and querying example take a look at this FAQ item
If you would like to discuss this further please email me at [email protected]
Later,
Rob Misek
Tangosol, Inc.
Coherence: Cluster your Work. Work your Cluster.

No Bios Update for Satellite: L755D-S5204 / Inability to change Memory Settings in Bios

Ok so I bought two new 8GB of BLUE Kingston Hyperx 1600 MHZ Memory Modules with heat spreaders recently from newegg.
I installed them, and my system recognizes the full 8 GB, but when running CPU-Z the memory MHZ is registering in at 665.5 MHZ.
I want to be able to run my Memory at least the STANDARD minimum 1333 MHZ if not be able to change the MHZ if possible to 1600 MHZ. I CANNOT DO THIS WITH THE BIOS THAT CAME WITH MY SYSTEM, AND I CANNOT FIND A BIOS UPDATE ANYWHERE ON THE TOSHIBA SITE THAT WILL LET ME DO THIS.
My system Laptop Satellite L755D-S5204 has the basic Bios that came with the system. However I do not know or CAN NOT FIND any flash updates to update the bios so I can change these setting.
My question to Toshiba Tech support is it possible to clock my system memory higher, and how do I do this with a BIOS that doesn't let me make any changes to my Voltage to my Memory, and doesn't let me make any changes to system memory or memory timing settings??
When you figure that out and if you could possibly help me resolve this problem, please email me because as a computer technician I am really intrigued as to the reason why Toshiba doesn't have a FLASH BIOS UPDATE that will let you change the Memory settings, and Memory Timings!!
Thanks,
Michael Richins
Comptia A+ Computer Technician

BIOS does not provide such option!
I have no idea what graphic card you have but for example the Sat P850-138 was equipped with an NVIDIA GeForce GT 630M graphic card.
This GPU supports dedicated VRAM (default 2048MB)
The available graphics memory can be expanded using system memory, through TurboCache
In case the system memory would be expanded to 6GB RAM, the TurboCache technology could use up to 4,095 MB VRAM

Performance optimization related.

Hi.
I am doing Performance optimization on code.
Actually, I am doing performance optimization for old code where it is of JDK1.4 related. I met up with a doubt when I optimize code for JDK1.5.
Problem statement:
Collection errors = new ArrayList();
errors.add(new GenericException(ErrorCodes.EMPLOYEE_INVALID_PERMISSION));
setErrorsInRequest(request, errors);In the above code the compiler tells us to Parameterize the Collection type reference. If we don't make any parameterization for Collection type, will that be dealing with Performace issue?
Please help me out to resolve the problem statement.
Thanks and regards,
Leslie V
www.googlestepper.blogspot.com
www.scrollnroll.blogspot.com

If we don't make any parameterization for Collection type, will that be dealing with Performace issue?No. Not really. But performance isn't really the issue... it's runtime-type-safety which is at issue. There's nothing to prevent me from adding an Integer (like an error number) to your collection of exceptions.
And "GenericException"... Sheesh, come down from the trees allready. WTF am I (the user of this class/method/package) supposed to with a friggin "GenericException"... you may as well have thrown a raw RuntimeException and saved all that cumbersom interveening try/catch code.

Installation of central instance - memory settings

Hi All,
I have a question about the memory settings reg. the ABAP / Java Add-In installation (Central system).
Installation of CI:
When I install the central instance, I provide a value for the Instance Memory Management.
Installation of DI:
In the step where I install the database instance, I provide again a value for Instance Memory.
Q1: The memory value for the Central instance later is visible in the profile for the CI. But where does the DI value go? How could I change it?
Q2: The value for the Java JVM (heap size) - is this value additional to the value of the CI, or part of the CI's memory. So could I set heap size to 2M while the CI's memory is set to 1M?
Any hints are appreciated.
Thx.
KB
System
- Win2K (Win32)
- Oracle

Q1: The memory value for the Central instance later is visible in the profile for the CI. But where does the DI value go? How could I change it?
--> You can ignore this, there is no INSTANCE memory for your database. If you want to configure the memory settings for your RDBMS software it'll depend on what software it is... For Sql Server it's in the Enterprise Manager in Oracle you can edit the init<SID>.ora file...
Q2: The value for the Java JVM (heap size) - is this value additional to the value of the CI, or part of the CI's memory. So could I set heap size to 2M while the CI's memory is set to 1M?
--> This value is specific to your JVM heap, so it's not additive or related to your CI.

Regarding performance optimization and tuning...

hi all,
<b>please provide me the performance tuning scenarios and parameters of an R/3 system with Oracle..</b>
i heartly welcome all docs and pdf links or notes related to this issue..
please provide ur suggestions at the earliest...
expecting ur response..
<i>Vineeth</i>

Hello,
there are many SAP Notes regarding performance issues. Here are just a couple of them:
618868
805934
793113
805934
Please also have a look at the lists of the relating Notes at the end of each Note.
But still much more effective would be to read the book of
<a href="http://www.sap-press.de/katalog/buecher/titel/gp/titelID-1155?GalileoSession=66220888A2.lRCIISlE">T.Schneider Performance Optimization Guide</a>.
It's the best performance tuning guide. The course ADM315 (or BC315?) ist also very helpful.
Regards,
Natalia

DRM Performance Optimization Memory Settings

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