Oracle DBA FAQs - 2
Differentiate between TRUNCATE and DELETE.
The Delete command will log the data changes in the log file where as the truncate will simply remove the data without it. Hence Data removed by Delete command can be rolled back but not the data removed by TRUNCATE. Truncate is a DDL statement whereas DELETE is a DML statement.
What is the maximum buffer size that can be specified using the DBMS_OUTPUT.ENABLE function?
1000000
Can you use a commit statement within a database trigger?
Yes, if you are using autonomous transactions in the Database triggers.
What is an UTL_FILE? What are different procedures and functions associated with it?
The UTL_FILE package lets your PL/SQL programs read and write operating system (OS) text files. It provides a restricted version of standard OS stream file input/output (I/O).
Subprogram -Description
FOPEN function-Opens a file for input or output with the default line size.
IS_OPEN function -Determines if a file handle refers to an open file.
FCLOSE procedure -Closes a file.
FCLOSE_ALL procedure -Closes all open file handles.
GET_LINE procedure -Reads a line of text from an open file.
PUT procedure-Writes a line to a file. This does not append a line terminator.
NEW_LINE procedure-Writes one or more OS-specific line terminators to a file.
PUT_LINE procedure -Writes a line to a file. This appends an OS-specific line terminator.
PUTF procedure -A PUT procedure with formatting.
FFLUSH procedure-Physically writes all pending output to a file.
FOPEN function -Opens a file with the maximum line size specified.
Difference between database triggers and form triggers?
Database triggers are fired whenever any database action like INSERT, UPATE, DELETE, LOGON LOGOFF etc occurs. Form triggers on the other hand are fired in response to any event that takes place while working with the forms, say like navigating from one field to another or one block to another and so on.
What is OCI. What are its uses?
OCI is Oracle Call Interface. When applications developers demand the most powerful interface to the Oracle Database Server, they call upon the Oracle Call Interface (OCI). OCI provides the most comprehensive access to all of the Oracle Database functionality. The newest performance, scalability, and security features appear first in the OCI API. If you write applications for the Oracle Database, you likely already depend on OCI. Some types of applications that depend upon OCI are:
· PL/SQL applications executing SQL
· C++ applications using OCCI
· Java applications using the OCI-based JDBC driver
· C applications using the ODBC driver
· VB applications using the OLEDB driver
· Pro*C applications
· Distributed SQL
What are ORACLE PRECOMPILERS?
A precompiler is a tool that allows programmers to embed SQL statements in high-level source programs like C, C++, COBOL, etc. The precompiler accepts the source program as input, translates the embedded SQL statements into standard Oracle runtime library calls, and generates a modified source program that one can compile, link, and execute in the usual way. Examples are the Pro*C Precompiler for C, Pro*Cobol for Cobol, SQLJ for Java etc.
What is syntax for dropping a procedure and a function? Are these operations possible?
Drop Procedure/Function ; yes, if they are standalone procedures or functions. If they are a part of a package then one have to remove it from the package definition and body and recompile the package.
How to check if Apps 11i System is Autoconfig enabled ?
Under $AD_TOP/bin check for file adcfginfo.sh and if this exists use adcfginfo.sh contextfile= show=enabled
If this file is not there , look for any configuration file under APPL_TOP if system is Autoconfig enabled then you will see entry like
How to check if Oracle Apps 11i System is Rapid Clone enabled ?
For syetem to be Rapid Clone enabled , it should be Autoconfig enabled (Check above How to confirm if Apps 11i is Autoconfig enabled). You should have Rapid Clone Patches applied , Rapid Clone is part of Rapid Install Product whose Family Pack Name is ADX. By default all Apps 11i Instances 11.5.9 and above are Autoconfig and Rapid Clone enabled.
Whats is difference between two env files in .env and APPS.env under $APPL_TOP ?
APPS.env is main environment file which inturn calls other environment files like .env under $APPL_TOP, .env under 806 ORACLE_HOME and custom.env for any Customized environment files.
Whats main concurrent Manager types.
# ICM - Internal Concurrent Manager which manages concurrent Managers
# Standard Managers - Which Manage processesing of requests.
# CRM - Conflict Resolution Managers , resolve conflicts in case of incompatibility.
Whats US
US France
Where is Concurrent Manager log file location.
By default standard location is $APPLCSF/$APPLLOG , in some cases it can go to $FND_TOP/log as well.
Where would i find .rf9 file, and what execatly it dose ?
These files are used during restart of patch in case of patch failure because of some reason.
Where is appsweb.cfg or appsweb_$CONTEXT.cfg stored and why its used ?
This file is defined by environment variable FORMS60_WEB_CONFIG_FILE This is usually in directory $OA_HTML/bin on forms tier.
This file is used by any forms client session. When a user try to access forms , f60webmx picks up this file and based on this configuration file creates a forms session to user/client.
What is Multi Node System ?
Multi Node System in Oracle Applications 11i means you have Applications 11i Component on more than one system. Typical example is Database, Concurrent Manager on one machine and forms, Web Server on second machine is example of Two Node System.
Can a function take OUT parameters. If not why?
yes, IN, OUT or IN OUT.
Can the default values be assigned to actual parameters?
Yes. In such case you don’t need to specify any value and the actual parameter will take the default value provided in the function definition.
What is difference between a formal and an actual parameter?
The formal parameters are the names that are declared in the parameter list of the header of a module. The actual parameters are the values or expressions placed in the parameter list of the actual call to the module.
What are different modes of parameters used in functions and procedures?
There are three different modes of parameters: IN, OUT, and IN OUT.
IN - The IN parameter allows you to pass values in to the module, but will not pass anything out of the module and back to the calling PL/SQL block. In other words, for the purposes of the program, its IN parameters function like constants. Just like constants, the value of the formal IN parameter cannot be changed within the program. You cannot assign values to the IN parameter or in any other way modify its value.
IN is the default mode for parameters. IN parameters can be given default values in the program header.
OUT - An OUT parameter is the opposite of the IN parameter. Use the OUT parameter to pass a value back from the program to the calling PL/SQL block. An OUT parameter is like the return value for a function, but it appears in the parameter list and you can, of course, have as many OUT parameters as you like.
Inside the program, an OUT parameter acts like a variable that has not been initialised. In fact, the OUT parameter has no value at all until the program terminates successfully (without raising an exception, that is). During the execution of the program, any assignments to an OUT parameter are actually made to an internal copy of the OUT parameter. When the program terminates successfully and returns control to the calling block, the value in that local copy is then transferred to the actual OUT parameter. That value is then available in the calling PL/SQL block.
IN OUT - With an IN OUT parameter, you can pass values into the program and return a value back to the calling program (either the original, unchanged value or a new value set within the program). The IN OUT parameter shares two restrictions with the OUT parameter:
An IN OUT parameter cannot have a default value.
An IN OUT actual parameter or argument must be a variable. It cannot be a constant, literal, or expression, since these formats do not provide a receptacle in which PL/SQL can place the outgoing value.
The Delete command will log the data changes in the log file where as the truncate will simply remove the data without it. Hence Data removed by Delete command can be rolled back but not the data removed by TRUNCATE. Truncate is a DDL statement whereas DELETE is a DML statement.
1000000
Yes, if you are using autonomous transactions in the Database triggers.
The UTL_FILE package lets your PL/SQL programs read and write operating system (OS) text files. It provides a restricted version of standard OS stream file input/output (I/O).
Subprogram -Description
FOPEN function-Opens a file for input or output with the default line size.
IS_OPEN function -Determines if a file handle refers to an open file.
FCLOSE procedure -Closes a file.
FCLOSE_ALL procedure -Closes all open file handles.
GET_LINE procedure -Reads a line of text from an open file.
PUT procedure-Writes a line to a file. This does not append a line terminator.
NEW_LINE procedure-Writes one or more OS-specific line terminators to a file.
PUT_LINE procedure -Writes a line to a file. This appends an OS-specific line terminator.
PUTF procedure -A PUT procedure with formatting.
FFLUSH procedure-Physically writes all pending output to a file.
FOPEN function -Opens a file with the maximum line size specified.
Database triggers are fired whenever any database action like INSERT, UPATE, DELETE, LOGON LOGOFF etc occurs. Form triggers on the other hand are fired in response to any event that takes place while working with the forms, say like navigating from one field to another or one block to another and so on.
OCI is Oracle Call Interface. When applications developers demand the most powerful interface to the Oracle Database Server, they call upon the Oracle Call Interface (OCI). OCI provides the most comprehensive access to all of the Oracle Database functionality. The newest performance, scalability, and security features appear first in the OCI API. If you write applications for the Oracle Database, you likely already depend on OCI. Some types of applications that depend upon OCI are:
· PL/SQL applications executing SQL
· C++ applications using OCCI
· Java applications using the OCI-based JDBC driver
· C applications using the ODBC driver
· VB applications using the OLEDB driver
· Pro*C applications
· Distributed SQL
A precompiler is a tool that allows programmers to embed SQL statements in high-level source programs like C, C++, COBOL, etc. The precompiler accepts the source program as input, translates the embedded SQL statements into standard Oracle runtime library calls, and generates a modified source program that one can compile, link, and execute in the usual way. Examples are the Pro*C Precompiler for C, Pro*Cobol for Cobol, SQLJ for Java etc.
Drop Procedure/Function ; yes, if they are standalone procedures or functions. If they are a part of a package then one have to remove it from the package definition and body and recompile the package.
How to check if Apps 11i System is Autoconfig enabled ?
Under $AD_TOP/bin check for file adcfginfo.sh and if this exists use adcfginfo.sh contextfile=
If this file is not there , look for any configuration file under APPL_TOP if system is Autoconfig enabled then you will see entry like
For syetem to be Rapid Clone enabled , it should be Autoconfig enabled (Check above How to confirm if Apps 11i is Autoconfig enabled). You should have Rapid Clone Patches applied , Rapid Clone is part of Rapid Install Product whose Family Pack Name is ADX. By default all Apps 11i Instances 11.5.9 and above are Autoconfig and Rapid Clone enabled.
APPS
# ICM - Internal Concurrent Manager which manages concurrent Managers
# Standard Managers - Which Manage processesing of requests.
# CRM - Conflict Resolution Managers , resolve conflicts in case of incompatibility.
By default standard location is $APPLCSF/$APPLLOG , in some cases it can go to $FND_TOP/log as well.
These files are used during restart of patch in case of patch failure because of some reason.
This file is defined by environment variable FORMS60_WEB_CONFIG_FILE This is usually in directory $OA_HTML/bin on forms tier.
This file is used by any forms client session. When a user try to access forms , f60webmx picks up this file and based on this configuration file creates a forms session to user/client.
Multi Node System in Oracle Applications 11i means you have Applications 11i Component on more than one system. Typical example is Database, Concurrent Manager on one machine and forms, Web Server on second machine is example of Two Node System.
Can a function take OUT parameters. If not why?
yes, IN, OUT or IN OUT.
Yes. In such case you don’t need to specify any value and the actual parameter will take the default value provided in the function definition.
The formal parameters are the names that are declared in the parameter list of the header of a module. The actual parameters are the values or expressions placed in the parameter list of the actual call to the module.
There are three different modes of parameters: IN, OUT, and IN OUT.
IN - The IN parameter allows you to pass values in to the module, but will not pass anything out of the module and back to the calling PL/SQL block. In other words, for the purposes of the program, its IN parameters function like constants. Just like constants, the value of the formal IN parameter cannot be changed within the program. You cannot assign values to the IN parameter or in any other way modify its value.
IN is the default mode for parameters. IN parameters can be given default values in the program header.
OUT - An OUT parameter is the opposite of the IN parameter. Use the OUT parameter to pass a value back from the program to the calling PL/SQL block. An OUT parameter is like the return value for a function, but it appears in the parameter list and you can, of course, have as many OUT parameters as you like.
Inside the program, an OUT parameter acts like a variable that has not been initialised. In fact, the OUT parameter has no value at all until the program terminates successfully (without raising an exception, that is). During the execution of the program, any assignments to an OUT parameter are actually made to an internal copy of the OUT parameter. When the program terminates successfully and returns control to the calling block, the value in that local copy is then transferred to the actual OUT parameter. That value is then available in the calling PL/SQL block.
IN OUT - With an IN OUT parameter, you can pass values into the program and return a value back to the calling program (either the original, unchanged value or a new value set within the program). The IN OUT parameter shares two restrictions with the OUT parameter:
An IN OUT parameter cannot have a default value.
An IN OUT actual parameter or argument must be a variable. It cannot be a constant, literal, or expression, since these formats do not provide a receptacle in which PL/SQL can place the outgoing value.
Awesome. You have posted so many interesting topics in a single post. I was just looking for some information about delete and truncate statements but got a whole set of other valuable information too. From the above post I learnt so many other Oracle facts that will enhance my knowledge. Thanks