What command would you use to create a backup control file?
Alter database backup control file to trace.
Alter database backup control file to trace.
Give the stages of instance startup to a usable state where normal users may access it.
STARTUP NOMOUNT - Instance startup
STARTUP MOUNT - The database is mounted
STARTUP OPEN - The database is opened
STARTUP NOMOUNT - Instance startup
STARTUP MOUNT - The database is mounted
STARTUP OPEN - The database is opened
What column differentiates the V$ views to the GV$ views and how?
The INST_ID column which indicates the instance in a RAC environment the information came from.
The INST_ID column which indicates the instance in a RAC environment the information came from.
How would you go about generating an EXPLAIN plan?
Create a plan table with utlxplan.sql.
Use the explain plan set statement_id = 'tst1' into plan_table for a SQL statement
Look at the explain plan with utlxplp.sql or utlxpls.sql
Create a plan table with utlxplan.sql.
Use the explain plan set statement_id = 'tst1' into plan_table for a SQL statement
Look at the explain plan with utlxplp.sql or utlxpls.sql
How would you go about increasing the buffer cache hit ratio?
Use the buffer cache advisory over a given workload and then query the v$db_cache_advice table. If a change was necessary then I would use the alter system set db_cache_size command.
Use the buffer cache advisory over a given workload and then query the v$db_cache_advice table. If a change was necessary then I would use the alter system set db_cache_size command.
Explain an ORA-01555
You get this error when you get a snapshot too old within rollback. It can usually be solved by increasing the undo retention or increasing the size of rollbacks. You should also look at the logic involved in the application getting the error message.
You get this error when you get a snapshot too old within rollback. It can usually be solved by increasing the undo retention or increasing the size of rollbacks. You should also look at the logic involved in the application getting the error message.
Explain the difference between $ORACLE_HOME and $ORACLE_BASE.
ORACLE_BASE is the root directory for oracle. ORACLE_HOME located beneath ORACLE_BASE is where the oracle products reside.
ORACLE_BASE is the root directory for oracle. ORACLE_HOME located beneath ORACLE_BASE is where the oracle products reside.
How would you determine the time zone under which a database was operating?
select DBTIMEZONE from dual;
select DBTIMEZONE from dual;
Explain the use of setting GLOBAL_NAMES equal to TRUE.
Setting GLOBAL_NAMES dictates how you might connect to a database. This variable is either TRUE or FALSE and if it is set to TRUE it enforces database links to have the same name as the remote database to which they are linking.
Setting GLOBAL_NAMES dictates how you might connect to a database. This variable is either TRUE or FALSE and if it is set to TRUE it enforces database links to have the same name as the remote database to which they are linking.
What command would you use to encrypt a PL/SQL application?
WRAP
WRAP
Explain the difference between a FUNCTION, PROCEDURE and PACKAGE.
A function and procedure are the same in that they are intended to be a collection of PL/SQL code that carries a single task. While a procedure does not have to return any values to the calling application, a function will return a single value. A package on the other hand is a collection of functions and procedures that are grouped together based on their commonality to a business function or application.
A function and procedure are the same in that they are intended to be a collection of PL/SQL code that carries a single task. While a procedure does not have to return any values to the calling application, a function will return a single value. A package on the other hand is a collection of functions and procedures that are grouped together based on their commonality to a business function or application.
Explain the use of table functions.
Table functions are designed to return a set of rows through PL/SQL logic but are intended to be used as a normal table or view in a SQL statement. They are also used to pipeline information in an ETL process.
Table functions are designed to return a set of rows through PL/SQL logic but are intended to be used as a normal table or view in a SQL statement. They are also used to pipeline information in an ETL process.
Name three advisory statistics you can collect.
Buffer Cache Advice, Segment Level Statistics, & Timed Statistics
Buffer Cache Advice, Segment Level Statistics, & Timed Statistics
Where in the Oracle directory tree structure are audit traces placed?
In unix $ORACLE_HOME/rdbms/audit, in Windows the event viewer
In unix $ORACLE_HOME/rdbms/audit, in Windows the event viewer
Explain materialized views and how they are used.
Materialized views are objects that are reduced sets of information that have been summarized, grouped, or aggregated from base tables. They are typically used in data warehouse or decision support systems.
Materialized views are objects that are reduced sets of information that have been summarized, grouped, or aggregated from base tables. They are typically used in data warehouse or decision support systems.
When a user process fails, what background process cleans up after it?
PMON
PMON
What background process refreshes materialized views?
The Job Queue Processes.
The Job Queue Processes.
How would you determine what sessions are connected and what resources they are waiting for?
Use of V$SESSION and V$SESSION_WAIT
Use of V$SESSION and V$SESSION_WAIT
Describe what redo logs are.
Redo logs are logical and physical structures that are designed to hold all the changes made to a database and are intended to aid in the recovery of a database.
Redo logs are logical and physical structures that are designed to hold all the changes made to a database and are intended to aid in the recovery of a database.
How would you force a log switch?
ALTER SYSTEM SWITCH LOGFILE;
ALTER SYSTEM SWITCH LOGFILE;
Give two methods you could use to determine what DDL changes have been made.
You could use Logminer or Streams
You could use Logminer or Streams
What does coalescing a tablespace do?
Coalescing is only valid for dictionary-managed tablespaces and de-fragments space by combining neighboring free extents into large single extents.
Coalescing is only valid for dictionary-managed tablespaces and de-fragments space by combining neighboring free extents into large single extents.
What is the difference between a TEMPORARY tablespace and a PERMANENT tablespace?
A temporary tablespace is used for temporary objects such as sort structures while permanent tablespaces are used to store those objects meant to be used as the true objects of the database.
A temporary tablespace is used for temporary objects such as sort structures while permanent tablespaces are used to store those objects meant to be used as the true objects of the database.
Name a tablespace automatically created when you create a database.
The SYSTEM tablespace.
The SYSTEM tablespace.
When creating a user, what permissions must you grant to allow them to connect to the database?
Grant the CONNECT to the user.
Grant the CONNECT to the user.
How do you add a data file to a tablespace
ALTER TABLESPACE <tablespace_name> ADD DATAFILE <datafile_name> SIZE
ALTER TABLESPACE <tablespace_name> ADD DATAFILE <datafile_name> SIZE
How do you resize a data file?
ALTER DATABASE DATAFILE <datafile_name> RESIZE <new_size>;
ALTER DATABASE DATAFILE <datafile_name> RESIZE <new_size>;
What view would you use to look at the size of a data file?
DBA_DATA_FILES
DBA_DATA_FILES
What view would you use to determine free space in a tablespace?
DBA_FREE_SPACE
DBA_FREE_SPACE
How would you determine who has added a row to a table?
Turn on fine grain auditing for the table.
Turn on fine grain auditing for the table.
How can you rebuild an index?
ALTER INDEX <index_name> REBUILD;
ALTER INDEX <index_name> REBUILD;
Explain what partitioning is and what its benefit is.
Partitioning is a method of taking large tables and indexes and splitting them into smaller, more manageable pieces.
Partitioning is a method of taking large tables and indexes and splitting them into smaller, more manageable pieces.
You have just compiled a PL/SQL package but got errors, how would you view the errors?
SHOW ERRORS
SHOW ERRORS
How can you gather statistics on a table?
The ANALYZE command.
The ANALYZE command.
How can you enable a trace for a session?
Use the DBMS_SESSION.SET_SQL_TRACE or
Use ALTER SESSION SET SQL_TRACE = TRUE;
Use the DBMS_SESSION.SET_SQL_TRACE or
Use ALTER SESSION SET SQL_TRACE = TRUE;
What is the difference between the SQL*Loader and IMPORT utilities?
These two Oracle utilities are used for loading data into the database. The difference is that the import utility relies on the data being produced by another Oracle utility EXPORT while the SQL*Loader utility allows data to be loaded that has been produced by other utilities from different data sources just so long as it conforms to ASCII formatted or delimited files.
These two Oracle utilities are used for loading data into the database. The difference is that the import utility relies on the data being produced by another Oracle utility EXPORT while the SQL*Loader utility allows data to be loaded that has been produced by other utilities from different data sources just so long as it conforms to ASCII formatted or delimited files.
Name two files used for network connection to a database.
TNSNAMES.ORA and SQLNET.ORA
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TNSNAMES.ORA and SQLNET.ORA
Are there any undocumented commands in Oracle? (for DBA)
Sure there are, but it is hard to find them. Look at these examples:
From Server Manager (Oracle7.3 and above): ORADEBUG HELP
It looks like one can change memory locations with the ORADEBUG POKE command. Anyone brave enough to test this one for us? Previously this functionality was available with ORADBX (ls -l $ORACLE_HOME/rdbms/lib/oradbx.o; make -f oracle.mk oradbx) SQL*Plus: ALTER SESSION SET CURRENT_SCHEMA = SYS
Sure there are, but it is hard to find them. Look at these examples:
From Server Manager (Oracle7.3 and above): ORADEBUG HELP
It looks like one can change memory locations with the ORADEBUG POKE command. Anyone brave enough to test this one for us? Previously this functionality was available with ORADBX (ls -l $ORACLE_HOME/rdbms/lib/oradbx.o; make -f oracle.mk oradbx) SQL*Plus: ALTER SESSION SET CURRENT_SCHEMA = SYS
If the maximum record retrieved property of the query is set to 10 then a summary value will be calculated?
Only for 10 records.
Only for 10 records.
What are the different objects that you cannot copy or reference in object groups?
Objects of different modules
Another object groups
Individual block dependent items
Program units.
Objects of different modules
Another object groups
Individual block dependent items
Program units.
What is an OLE?
Object Linking & Embedding provides you with the capability to integrate objects from many Ms-Windows applications into a single compound document creating integrated applications enables you to use the features form .
Object Linking & Embedding provides you with the capability to integrate objects from many Ms-Windows applications into a single compound document creating integrated applications enables you to use the features form .
Can a repeating frame be created without a data group as a base?
No
No
Is it possible to set a filter condition in a cross product group in matrix reports?
No
No
What is Overloading of procedures ?
The Same procedure name is repeated with parameters of different datatypes and parameters in different positions, varying number of parameters is called overloading of procedures. e.g. DBMS_OUTPUT put_line
The Same procedure name is repeated with parameters of different datatypes and parameters in different positions, varying number of parameters is called overloading of procedures. e.g. DBMS_OUTPUT put_line
What are the return values of functions SQLCODE and SQLERRM ? What is Pragma EXECPTION_INIT ? Explain the usage ?
SQLCODE returns the latest code of the error that has occurred.
SQLERRM returns the relevant error message of the SQLCODE.
SQLCODE returns the latest code of the error that has occurred.
SQLERRM returns the relevant error message of the SQLCODE.
What are the datatypes a available in PL/SQL ?
Some scalar data types such as NUMBER, VARCHAR2, DATE, CHAR, LONG, BOOLEAN. Some composite data types such as RECORD & TABLE.
Some scalar data types such as NUMBER, VARCHAR2, DATE, CHAR, LONG, BOOLEAN. Some composite data types such as RECORD & TABLE.
What are the two parts of a procedure ?
Procedure Specification and Procedure Body.
Procedure Specification and Procedure Body.
What is the basic structure of PL/SQL ?
PL/SQL uses block structure as its basic structure. Anonymous blocks or nested blocks can be used in PL/SQL
PL/SQL uses block structure as its basic structure. Anonymous blocks or nested blocks can be used in PL/SQL
What is PL/SQL table ?
Objects of type TABLE are called "PL/SQL tables", which are modeled as (but not the same as) database tables, PL/SQL tables use a primary PL/SQL tables can have one column and a primary key. Cursors
Objects of type TABLE are called "PL/SQL tables", which are modeled as (but not the same as) database tables, PL/SQL tables use a primary PL/SQL tables can have one column and a primary key. Cursors
WHAT IS RMAN ? (for DBA)
Recovery Manager is a tool that: manages the process of creating backups and also manages the process of restoring and recovering from them.
Recovery Manager is a tool that: manages the process of creating backups and also manages the process of restoring and recovering from them.
Explain UNION,MINUS,UNION ALL, INTERSECT ?
INTERSECT returns all distinct rows selected by both queries.MINUS - returns all distinct rows selected by the first query but not by the second.UNION - returns all distinct rows selected by either queryUNION ALL - returns all rows selected by either query, including all duplicates.
INTERSECT returns all distinct rows selected by both queries.MINUS - returns all distinct rows selected by the first query but not by the second.UNION - returns all distinct rows selected by either queryUNION ALL - returns all rows selected by either query, including all duplicates.
Should the OEM Console be displayed at all times (when there are scheduled jobs)? (for DBA)
When a job is submitted the agent will confirm the status of the job. When the status shows up as scheduled, you can close down the OEM console. The processing of the job is managed by the OIA (Oracle Intelligent Agent). The OIA maintains a .jou file in the agent's subdirectory. When the console is launched communication with the Agent is established and the contents of the .jou file (binary) are reported to the console job subsystem. Note that OEM will not be able to send e-mail and paging notifications when the Console is not started.
When a job is submitted the agent will confirm the status of the job. When the status shows up as scheduled, you can close down the OEM console. The processing of the job is managed by the OIA (Oracle Intelligent Agent). The OIA maintains a .jou file in the agent's subdirectory. When the console is launched communication with the Agent is established and the contents of the .jou file (binary) are reported to the console job subsystem. Note that OEM will not be able to send e-mail and paging notifications when the Console is not started.
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