What is "abstract schema" in CMP 2.0

I saw this word in the configuration dialog of J2EESDK 1.3. What's that?

Abstract schema refers to the persistent fields and relationship fields of an entity bean which uses container-managed persistence (CMP). You specify an identifier to refer to a bean's abstract schema. Then you can compose EJB QL statements for custom finder & select methods. So, if you have a student entity bean, let's say its abstract schema identifier is studentEJB. To find all students with CMP field 'name' equal to parameter 1, your EJB QL query would be:
select object (s) from studentEJB s
where s.name = ?1
More information can be found in Chapter 11 of EJB 2.0 spec (really, it's not bad). Good luck.

Similar Messages

EJB, Moving Target DB, Abstract Schema

I apologize in advance for seeming clueless. My explanation is this: There is no money. I have inexperience staff. I've been away from building architectures too long to be specific. I can't buy a contractor. I need some advice.
We are converting many Access applications to Java/J2EE/AnyRelationalDB The way we have planned to approach this is to divide the DBs into various classes, say Personnel records, Vehicles, ...so on). These DBs will be moving targets that will change as we are able to discover Access applications that add/change features to whatever class of DB we're working with at the moment.
My goal is to eliminate changing each and every App everytime some DB parameter changes (DBMS, changed attribute, ..., etc). I think EBJ/abstract schemas will let me to get a generic view of the DB and insulate the App from the very real possibility of changing DB parameters.
I need some help verifying this or pointing me in a better direction.
Thanks for your help,
Bob

I think your best option is to implement CMP entity beans with a facade of services (business logic) that access the beans as tables in a DB. The only advantage of doing this will be the DB vendor independence and transparency because you define static queries in a declarative way.
I don't quite understand what you mean by DB parameters. But if you refer to changes to the database schema like new tables, new fields or changes to existing fields, you still need to align those changes with the attribuites in your application.
Cheers

Moving Target DB and Abstract Schema

I apologize in advance for seeming clueless. My explanation is this: There is no money. I have inexperience staff. I've been away from building architectures too long to be specific. I can't buy a contractor. I need some advice.
We are converting many Access applications to Java/J2EE/AnyRerelationalDB The way we have planned to approach this is to divide the DBs into various classes, say Personnel records, Vehicles, ...so on). These DBs will be moving targets that will change as we are able to discover Access applications that add/change features to whatever class of DB we're working with at the moment.
My goal is to eliminate changing each and every App everytime some DB parameter changes (DBMS, changed attribute, ..., etc). I think EBJ/abstract schemas will let me to get a generic view of the DB and insulate the App from the very real possibility of changing DB parameters.
I need some help verifying this or pointing me in a better direction.
Thanks for your help,
Bob

I apologize in advance for seeming clueless. My
explanation is this: There is no money. I have
inexperience staff. I've been away from building
architectures too long to be specific. I can't buy a
contractor. I need some advice.
We are converting many Access applications to
Java/J2EE/AnyRerelationalDB The way we have planned
to approach this is to divide the DBs into various
classes, say Personnel records, Vehicles, ...so on).
These DBs will be moving targets that will change as
s we are able to discover Access applications that
add/change features to whatever class of DB we're
working with at the moment.My first advice is that the description of you team doesn't bode well for the success of the project described in the second.
Let me frame it in another context to illuminate how dubious this sounds:
I want to build house with curved glass walls, high vaulted ceilings perched on a steep hillside. There is no money. I have inexperienced staff. I've been away from building houses too long to be specific. I can't buy a contractor.
My goal is to eliminate changing each and every App
everytime some DB parameter changes (DBMS, changed
attribute, ..., etc). I think EBJ/abstract schemas
will let me to get a generic view of the DB and
insulate the App from the very real possibility of
changing DB parameters.If you use an EJB layer than supports XDoclet or other portable CMP, yes, it will do this. However, it's not a simple and it your table structure changes significantly, your EJB will not work autmatically. The fact of the matter is that EJB is pretty complex and requires a lot of esoteric knowledge. Many EBJ projects have failed or produced terrible results. If you don't have any very capable developer/designers and/or have no developers with solid EJB experience I would under no circustances attempt this. EBJ is often overkill anyway. The real point of EJB is to help with distributed computing, not to abstract away the DB schema.
I simple approach that many people overlook is to use stored procedures. Stored procedures create a layer of abstraction between your code and the DB such that the DB can change without changing the code.

What is another schema name in oracle 1z0-051 exam ?

hi all
i want to prepare oracle 1z0-051 , i study SQL tutorial (HR schema) , and i have seen some questions. but some of tables is like (sales , customers ,promotion ...ets)
What are the schemas in this exam ? by the way all samples schema install in my database
and thx advace

In the exam you will get the snippet of the code that includes table structure and may be data in some tables in some questions. But every time they are different. so my advice is that you need to understand how to read a table definition and interpret. dont just mug up the things. Go to oracle documentation and read and try get the concept right.
I followed the book 'Oracle 11g- SQL Fundamental Exam Guide (Exam 1Z0-051)' it nearly covered all the topics and have good examples at the end of the chapter. happy studying.
You cane refer to 'http://www.oracle.com/technetwork/articles/sql/11g-schemamanagement-089869.html'
and 'Managing Schema Objects'

What is the schema name for service part planning module

Hi Experts,
i need the following info
1. what is the schema name for SPP module
say for example we call ASCP as MSC, in similar passion what is the name given to SPP.
2. I have searched for the table details in etrm site ( in R12.1.1 ) but it is not available, can anyone help me out to get the table details in SPP ?
Thanks for your valuable time.
Bye
Babu

Thanks Bob for your clarification.
Do you have any idea, which are all the table that got linked with SPP in the MSC schema ?
If we have any separate link in metalink, pls share that link.
Thanks again for your valuable time.
Babu Ji

What is Abstract class

Hello what is Abstract class

An abstract class is a class that can have one or more abstract methods in it.
An abstract method is a method that does not have a body. Only the signature is declared, leaving it up to a subclass to implement the method.
An often used example of this would be the abstract class shape, representing a two dimensional shape (for instance a circle or a square). This class has an abstract method getArea(), which gets you the size of the surface.
The implementation of this method would be something like returning Math.PI * radius * radius for the circle, while returning side * side for the square.
So while you can't do something like Shape s = new Shape(), you can do Shape s = new Square() and int x = s.getArea() after that.

What are the schemas/users provided in oracle12c installation

Hi Expeerts,
Like SCOTT in Oracle 9i and HR in Oracle11G, what is the schema in Oracle12c
I have installed Oracle 12c and could see only below users:
XS$NULL
SYSKM
SYSDG
SYSBACKUP
DVSYS
DVF
APEX_040200
APEX_PUBLIC_USER
FLOWS_FILES
LBACSYS
SPATIAL_CSW_ADMIN_USR
SPATIAL_WFS_ADMIN_USR
MDDATA
OLAPSYS
MDSYS
SI_INFORMTN_SCHEMA
ORDPLUGINS
ORDDATA
ORDSYS
CTXSYS
OJVMSYS
WMSYS
GSMCATUSER
ANONYMOUS
XDB
APPQOSSYS
DBSNMP
ORACLE_OCM
DIP
GSMUSER
GSMADMIN_INTERNAL
OUTLN
SYSTEM
AUDSYS
SYS
Please help me here

>
Like SCOTT in Oracle 9i and HR in Oracle11G, what is the schema in Oracle12c
I have installed Oracle 12c and could see only below users:
>
The short answer is to use the followings query to see what users are available
>
select con_id, common, username from cdb_users order by username
>
If you don't know what a CON_ID is or what CDB_USERS contains then you need to start by following that infamous advice: RTFM!
Seriously, many developers will NOT be successful and will have MANY issues similar to yours if they do not firt read the docs and learn about the new multitenant architecture that 12c introduces.
IMHO it is simply a MUST that people learn the basics of the new architecture of 12c or they will have problems/issues doing even simple things like: connecting to the proper database, starting up PDBs, creating users (common vs. local) and using the large set of new CDB_* views.
See my replies in these two threads for a larger discussion and more links to the doc sections to review:
https://forums.oracle.com/thread/2554568
https://forums.oracle.com/thread/2559874
In that second link I show you the queries you can execute to determine what containers you have and what service names map to those containers.
I also show why you need to answer a whole slew of questions and provide much more information to the forum when you ask questions re 12c:
1. Did you create:
A. A non-CDB PDB named ORCL
B. A CDB named ORCL with no PDBs
C. A CDB named ORCL with a PDB that you think is named ORCL but is really named PDBORCL
2. Is your CDB up and running?
3. Have your PDBs been opened?
4. Are you are trying to connect to CDB or PDB?
If you do a basic install and create a sample database (that would include the SCOTT schema) you will get:
1. A CDB named ORCL - this is the CDB$ROOT and will NOT have SCOTT since it is NOT the sample database
2. PDB$SEED - the 'seed' DB that will be used as a template when you create new PDBs
3. PDBORCL - this is the sample DB and has the SCOTT schema
So you are likely connecting to ORCL (the CDB) and that doesn't have a SCOTT schema as your exception indicates. You need to connect to PDBORCL and you can only do that after you open it.
One way to open your PDBs is to issue:
>
ALTER PLUGGABLE DATABASE ALL OPEN;
>
after you connect as SYS to the CDB. Then you need to open a connection to service name PDBORCL.
Please read the referenced threads above and the doc section on the multi-tenant architecture.
RTFM is going to be a very common response to anyone posting 12c questions if their question shows, as yours does, that the poster likely hasn't read the basic sections. There is simply too much new architecture to try to explain it in the forums.

What is star schema - pls explain with example

Hai.
what is star schema - pls explain with example
thanks in advance
Giri

Hi Giri,
SAP's BIW employs extended star schama
The extended star schema consists of a fact table (in two parts, E and F - f is the inbound table, E long-term storage). Dimension tables are connected to the fact tables via the DIMID(dimension id) which is a generated value and is stored in both dimension and fact tables. In addition, the dimension tables are connected to tables which hold master data values (or bind the dimension table to tables that hold the values), such as S tables, P, Q, X, Y. These dimension tables hold SIDs, again generated keys which relate values in the dimension table (the DIMIDs) with master data values. Thus, at the time of the query, join operations ensure that the master data values can be merged with the key figure values stored in the fact tables.
Truthfully, one does not need to understand this schema extensively in order to model in BI in SAP NetWeaver. It helps to understand master data, navigational attributes, etc. Otherwise, simply model the key figures in the fact table and the characteristics into dimensions and you're good - the application generates the star schema for you - you don't have to specify it.
See the transaction "LISTSCHEMA" which will show you the relationship between the F fact table and the other tables of the cube's star schema.
Also follow the link for more info:
http://help.sap.com/saphelp_nw04/helpdata/en/4c/89dc37c7f2d67ae10000009b38f889/content.htm
Thanks for any points you assign.
Regards

What does this scheme-name stand for ?

What does this <scheme-name> stand for? Does it stand for the name of this <read-write-backing-map-scheme> ?
<read-write-backing-map-scheme>
*<scheme-name>categoriesLoaderScheme</scheme-name>*
<internal-cache-scheme>
<local-scheme>
<scheme-ref>categories-eviction</scheme-ref>
</local-scheme>
</internal-cache-scheme>
<cachestore-scheme>
<class-scheme>
<class-name>com.demo.cache.coherence.categories.CategoryCacheLoader</class-name>
</class-scheme>
</cachestore-scheme>
<refresh-ahead-factor>0.5</refresh-ahead-factor>
</read-write-backing-map-scheme>
This excerpt is come form the following cache-config.xml file:
<cache-config>
   <distributed-scheme>
      <scheme-name>categories-cache-all-scheme</scheme-name>
      <service-name>DistributedCache</service-name>
      <backing-map-scheme>
      
      <read-write-backing-map-scheme>
         <scheme-name>categoriesLoaderScheme</scheme-name>
         <internal-cache-scheme>
            <local-scheme>
               <scheme-ref>categories-eviction</scheme-ref>
            </local-scheme>
         </internal-cache-scheme>
         <cachestore-scheme>
            <class-scheme>
               <class-name>com.demo.cache.coherence.categories.CategoryCacheLoader</class-name>
            </class-scheme>
         </cachestore-scheme>
         <refresh-ahead-factor>0.5</refresh-ahead-factor>
      </read-write-backing-map-scheme>
      </backing-map-scheme>
      <autostart>true</autostart>
   </distributed-scheme>
    
   <local-scheme>
      <scheme-name>categories-eviction</scheme-name>
      <expiry-delay>20s</expiry-delay>
   </local-scheme>
</cache-config>

If you look at the documentation here [http://download.oracle.com/docs/cd/E14526_01/coh.350/e14509/appcacheelements.htm#BABEFGCG] you will see that it does indeed specify the name of the scheme. The other XML tags are explained too.
JK

How to generate database schema from CMP?

I'm using JDeveloper 10g to design J2EE application in the Up-bottom manner. Then I have written UML model with CMP beans and now I would like deploy the model to the database. Is there a wizard to automaticly generate database schema from CMP beans?
Marek

Here are some links that might help you:
The Oracle XML Developer's Kits (XDK) contain the basic building blocks for reading, manipulating, transforming and viewing XML documents. Includes XML Schema Processor: supporting Java, C, and C++, allows use of XML simple and complex datatypes.
http://otn.oracle.com/tech/xml/xdkhome.html
Building Server-Side XML Schema Validation
Discusses how XML Schema can be used within Oracle9i to validate XML documents.
http://otn.oracle.com/tech/xml/xdk_sample/xdksample_093001.html
How XML Schemas Simplify Dynamic Content Management
With XML Schema now a W3C Recommendation, compare Document Type Definitions to XML Schema.
http://otn.oracle.com/tech/xml/htdocs/SchemDTD.html
Regards,
-rh

What is table schema name?

Hi,
I was looking at DatabaseMetaData::getColumns() while searching for a way to get a table's column names and I run into these ugly params catalog and schemaPattern. Of course nowhere on the sun's site could I find a definition of these terms although they're used quite often in the API documentation. So I turned to a specific DBMS provider and found out that catalog is a fancy term for the system metadata. But what about the String schema param? I usually see a table's schema referred to as the "structure" of the table, what columns it contains of which types. But I've never known this "schema" can have a string name. Anyone so kind to explain it to me or better point me to a text that has definitions and explanations of the concepts used in the JDBC API documentation? And more generally for JDK where do you folks usually go when you want a simple explanation of how things work, not the dry listing of function and parameter names? Look at MSDN for example, it is both a good reference and a reasonable self-contained tutorial. Not that I praise Microsoft but...
BTW I found that probably ResultSetMetaData is more suitable for my initial purposes, but still the questions bother me. So if you have any suggestion please let me know.
Thank you in advance

To answer your question, what is a table schema name?, it is the name of the schema that the table belongs to. If you have an Oracle database, MYDB, it will have at the very least two users which are SYS and SYSTEM, these are schema names, there are objects that exists in their schema. If you create a new user, JAKE, and then create a bunch of objects as JAKE, these objects are said to belong to the JAKE schema. All objects are like this, not just tables (indexes, sequence tables, triggers, etc.).

What is Abstract Portal Component?

Hi Experts,
Can anyone explain me the meaning of an Abstract Portal Component? What are the cases required to implement it.
Thanks in advance.

Hi Vinay,
The Abstract Portal Component is a class that offers a lean method for writing HTML commands to the Web client as well as for basic event handling. The programming effort is therefore greater for larger, interactive components.
you can understand by seeing the below links
[http://help.sap.com/saphelp_nw70/helpdata/EN/e3/fab74247e2b611e10000000a155106/content.htm]
[http://help.sap.com/saphelp_nw70/helpdata/EN/44/46bb2e70e20597e10000000a155369/frameset.htm]
Example:
[http://www.sdn.sap.com/irj/scn/index?rid=/library/uuid/60d39c32-3d7f-2c10-819b-f223c1c5d1c8&overridelayout=true]
hope this helps you

What is Abstract Data type ?

Shall i call a class to be an Abstract data type ?

jverd wrote:
I do not agree. For one thing, I'd consider classes realizations or implementations of ADTs. That nitpick aside, however, the easiest counterexample is a class with no member variables. The "D" of "ADT" is missing there. I wouldn't consder java.lang.Math and ADT, just a collection of functions and constants.I wouldn't say being implemented in a specific language takes anything away from an ADT. An implemented ADT is also an ADT.
Being an ADT doesn't require the existence of state. This was what you meant with "no member variables" right? ADTs can have or not have state.
Your final counterexample concerns so called free functions and constants (static in Java). They should be viewed as part of an ADT definition. But okay, Math itself cannot be considered an ADT so not every class, interface and enum is an ADT as I claimed. Sometimes they're used as namespaces for free functions and constants that have no natural home. Functions and constants associated with primitives have to go somewhere for example. But this usage is atypical.

What is APPS schema?

When I install Warehouse Builder,
In the wizard of BIS, it prompts me to enter
the username and password of apps schema?
What is the apps schema?

Take a look at the Warehouse Builder installation guide. You should be able to find it in the PDF directory on the product CD. There are two versions of Warehouse Builder -- one regular one and one that is intended for use with Oracle Applications. Make sure you pick the right one (not the one that says BIS), when the Oracle Universal Installer launches. If you've already gone ahead, you can remove the installation with the Installer, and then reinstall the regular version of Warehouse Builder.
By the way, this forum is dedicated to another product, not Warehouse Builder. However, we are planning to add a forum for Warehouse Builder soon.

What is that Schema password?

Hi.
What do you guys mean with schema password? Where do i find that?
I can't connect to iFS, the error message is "invalid username/password; logon denied".
But i have the right username/password, could the reason be that the webserver/servlet container is running on a different machine than the oracle db?
Thx.

Thx. I figured it out now. But i have another problem: I get the exception:
IFS-10176: Unable to get credential manager version.
java.sql.SQLException: ORA-06550: line 1, column 13:
PLS-00103: Encountered the symbol "." when expecting one of the following:
( - + mod not null <an identifier>
<a double-quoted delimited-identifier> <a bind variable> avg
count current exists max min prior sql stddev sum variance
execute forall time timestamp interval date
<a string literal with character set specification>
<a number> <a single-quoted SQL string>
The symbol "<an identifier>" was substituted for "." to continue.
I switched on the jdbc tracing and i think the problem is the following sql-statement:
DRVR DBG1 Output SQL: "BEGIN :1 := .IfsCredentialManagerPackage.getVersionString; END;"
It seems to me that there should be a schema name or a db name in formt of the dot.
Does anybody of you has an idea?
Thx, Daniel.

What is "abstract schema" in CMP 2.0

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