What is Buffer Manager?

What is Buffer Manager?
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1 Answer

Answer :

It is a program module, which is responsible for fetching data from disk storage into main  memory and deciding what data to be cache in memory.
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Related questions

How would you go about increasing the buffer cache hit ratio?

Description : How would you go about increasing the buffer cache hit ratio?

Last Answer : 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.

What is the maximum buffer size that can be specified using the DBMS_OUTPUT.ENABLE function?

Description : What is the maximum buffer size that can be specified using the DBMS_OUTPUT.ENABLE function?

Last Answer : 1,000,00

What is meant by redo log buffer ?

Description : What is meant by redo log buffer ?

Last Answer : Changes made to entries are written to the on-line redo log files. So that they can be used in roll forward operations during database recoveries. Before writing them into the redo log files ... buffers in SGA and LGWR will write into files frequently. LOG_BUFFER parameter will decide the size.

Name the buffer in which all the commands that are typed in are stored

Description : Name the buffer in which all the commands that are typed in are stored

Last Answer : ‘Edit’ Buffer

What is DB Buffer Cache Advisor?

Description : What is DB Buffer Cache Advisor?

Last Answer : The Buffer Cache Advisor provides advice on how to size the Database Buffer Cache to obtain optimal cache hit ratios. Member of Performance Advisors --> Memory Advisor pack.

What is kept in the Database Buffer Cache?

Description : What is kept in the Database Buffer Cache?

Last Answer : The database buffer cache is the portion of the SGA that holds copies of data blocks read from datafiles. All user processes concurrently connected to the instance share access to the database buffer cache.

How does one use ORADEBUG from Server Manager/ SQL*Plus? (for DBA

Description : How does one use ORADEBUG from Server Manager/ SQL*Plus? (for DBA

Last Answer : Execute the "ORADEBUG HELP" command from svrmgrl or sqlplus to obtain a list of valid ORADEBUG commands. Look at these examples: SQLPLUS> REM Trace SQL statements with bind variables SQLPLUS> oradebug ... oradebug lkdebug -a convres SQLPLUS> oradebug lkdebug -r (i.e 0x8066d338 from convres dump)

What is OEM (Oracle Enterprise Manager)? (for DBA

Description : What is OEM (Oracle Enterprise Manager)? (for DBA

Last Answer : OEM is a set of systems management tools provided by Oracle Corporation for managing the Oracle environment. It provides tools to monitor the Oracle environment and automate tasks (both one-time and repetitive in nature) to take database administration a step closer to "Lights Out" management.

What is Functional Setup Manager or FSM as it is more commonly known as?

Description : What is Functional Setup Manager or FSM as it is more commonly known as?

Last Answer : Oracle Fusion Functional Setup Manager (FSM) is an application that provides an end to-end guided process for managing your functional implementation projects throughout the entire implementation life cycle.

What is Authorization and Integrity manager?

Description : What is Authorization and Integrity manager?

Last Answer : It is the program module, which tests for the satisfaction of integrity constraint and checks the authority of user to access data.

What is File Manager?

Description : What is File Manager?

Last Answer : It is a program module, which manages the allocation of space on disk storage and data structure used to represent information stored on a disk.

What is Transaction Manager?

Description : What is Transaction Manager?

Last Answer : It is a program module, which ensures that database, remains in a consistent state despite system failures and concurrent transaction execution proceeds without conflicting.

What does "jumps off the screen" mean?

Description : What does "jumps off the screen" mean?

Last Answer : answer:AMD is a relatively small manufacturer but well established in the industry. In this context, AMD jumps off the screen at the guy doing the research into acquiring companies for ... chip manufacturing division, but AMD is the one that really stands out from an acquisition perspective.

How to add conditions in select statement in oracle?

Description : How to add conditions in select statement in oracle?

Last Answer : Just add the decode

How can I dump an oracle schema to a LOCAL file over a network connection from sqlplus?

Description : How can I dump an oracle schema to a LOCAL file over a network connection from sqlplus?

Last Answer : By connecting and spooling are you excluding the exp/imp commands (or expdb/impdb in 10g)?

What are the two ways to incorporate images into a oracle forms application?

Description : What are the two ways to incorporate images into a oracle forms application?

Last Answer : Boilerplate Images Image_items

Can one export a subset of a table? (for DBA

Description : Can one export a subset of a table? (for DBA

Last Answer : From Oracle8i one can use the QUERY= export parameter to selectively unload a subset of the data from a table. Look at this example: exp scott/tiger tables=emp query=\"where deptno=10\"

What are the types of visual attribute settings?

Description : What are the types of visual attribute settings?

Last Answer : Custom Visual attributes Default visual attributes Named Visual attributes. Window

How does one use the import/export utilities? (for DBA

Description : How does one use the import/export utilities? (for DBA

Last Answer : Look for the "imp" and "exp" executables in your $ORACLE_HOME/bin directory. One can run them interactively, using command line parameters, or using parameter files. Look at the imp/exp parameters ... and export data with the "Schema Manager" GUI that ships with Oracle Enterprise Manager (OEM).

what is a display item?

Description : what is a display item?

Last Answer : Display items are similar to text items but store only fetched or assigned values. Operators cannot navigate to a display item or edit the value it contains.

What is import/export and why does one need it? (for DBA

Description : What is import/export and why does one need it? (for DBA

Last Answer : The Oracle export (EXP) and import (IMP) utilities are used to perform logical database backup and recovery. They are also used to move Oracle data from one machine, database or schema to ... corruption. Ensure that all the data can be read. . Transporting tablespaces between databases . Etc.

Are there any troubleshooting tips for OEM? (for DBA

Description : Are there any troubleshooting tips for OEM? (for DBA

Last Answer : . Create the OEM repository with a user (which will manage the OEM) and store it in a tablespace that does not share any data with other database users. It is a bad practice to create ... successfully. Check the log to see the results of the execution rather than relying on this status.

Where can one get more information about TCL? (for DBA

Description : Where can one get more information about TCL? (for DBA

Last Answer : One can write custom event checking routines for OEM using the TCL (Tool Command Language) language. Check the following sites for more information about TCL: . The Tcl Developer Xchange - ... the OraTCL package . Tom Poindexter's Tcl Page - Oratcl was originally written by Tom Poindexter

How does one start the Oracle Intelligent Agent? (for DBA

Description : How does one start the Oracle Intelligent Agent? (for DBA

Last Answer : One needs to start an OIA (Oracle Intelligent Agent) process on all machines that will to be managed via OEM. For OEM 9i and above:

What is the Oracle Intelligent Agent? (for DBA

Description : What is the Oracle Intelligent Agent? (for DBA

Last Answer : The Oracle Intelligent Agent (OIA) is an autonomous process that needs to run on a remote node in the network to make the node OEM manageable. The Oracle Intelligent Agent is ... events registered in Enterprise Manager; and . Executing tasks associated with jobs submitted to Enterprise Manager.

What are the types of SQL Statement ?

Description : What are the types of SQL Statement ?

Last Answer : Data Definition Language : CREATE,ALTER,DROP,TRUNCATE,REVOKE,NO AUDIT & COMMIT.

How does one backout events and jobs during maintenance slots? (for DBA

Description : How does one backout events and jobs during maintenance slots? (for DBA

Last Answer : Managemnet and data collection activity can be suspended by imposing a blackout. Look at these examples: agentctl start blackout # Blackout the entrire agent agentctl stop blackout # Resume normal monitoring ... management agentctl start blackout -s jobs -d 00:20 # Blackout jobs for 20 minutes

What are the pre requisites ?

Description : What are the pre requisites ?

Last Answer : I. to modify data type of a column ? ii. to add a column with NOT NULL constraint ? To Modify the datatype of a column the column must be empty. to add a column with NOT NULL constrain, the table must be empty.

What kind of jobs can one schedule with OEM? (for DBA

Description : What kind of jobs can one schedule with OEM? (for DBA

Last Answer : OEM comes with pre-defined jobs like Export, Import, run OS commands, run sql scripts, SQL*Plus commands etc. It also gives you the flexibility of scheduling custom jobs written with the TCL language.

Difference between SUBSTR and INSTR ?

Description : Difference between SUBSTR and INSTR ?

Last Answer : INSTR (String1,String2(n,(m)),INSTR returns the position of the mth occurrence of the string 2 instring1. The search begins from nth position of string1.SUBSTR (String1 n,m)SUBSTR returns a character string of size m in string1, starting from nth position of string1.

Should the OEM Console be displayed at all times (when there are scheduled jobs)? (for DBA

Description : Should the OEM Console be displayed at all times (when there are scheduled jobs)? (for DBA

Last Answer : 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 ... that OEM will not be able to send e-mail and paging notifications when the Console is not started.

Explain UNION,MINUS,UNION ALL, INTERSECT ?

Description : Explain UNION,MINUS,UNION ALL, INTERSECT ?

Last Answer : 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.

WHY USE RMAN ? (for DBA

Description : WHY USE RMAN ? (for DBA

Last Answer : No extra costs Its available free ?RMAN introduced in Oracle 8 it has become simpler with newer versions and easier than user managed backups ?Proper security ?You are 100% sure your ... what need to backed up Knows what is required for recovery Knows what backups are redundant

WHAT IS RMAN ? (for DBA

Description : WHAT IS RMAN ? (for DBA

Last Answer : Recovery Manager is a tool that: manages the process of creating backups and also manages the process of restoring and recovering from them.

What is the basic structure of PL/SQL ?

Description : What is the basic structure of PL/SQL ?

Last Answer : PL/SQL uses block structure as its basic structure. Anonymous blocks or nested blocks can be used in PL/SQL.

What are the two parts of a procedure ?

Description : What are the two parts of a procedure ?

Last Answer : Procedure Specification and Procedure Body.

What are the datatypes a available in PL/SQL ?

Description : What are the datatypes a available in PL/SQL ?

Last Answer : Some scalar data types such as NUMBER, VARCHAR2, DATE, CHAR, LONG, BOOLEAN. Some composite data types such as RECORD & TABLE.

What are the return values of functions SQLCODE and SQLERRM ? What is Pragma EXECPTION_INIT ? Explain the usage ?

Description : What are the return values of functions SQLCODE and SQLERRM ? What is Pragma EXECPTION_INIT ? Explain the usage ?

Last Answer : SQLCODE returns the latest code of the error that has occurred. SQLERRM returns the relevant error message of the SQLCODE.

What is Overloading of procedures ?

Description : What is Overloading of procedures ?

Last Answer : 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

s it possible to set a filter condition in a cross product group in matrix reports?

Description : s it possible to set a filter condition in a cross product group in matrix reports?

Last Answer : No

Can a repeating frame be created without a data group as a base?

Description : Can a repeating frame be created without a data group as a base?

Last Answer : No

What is an OLE?

Description : What is an OLE?

Last Answer : 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 .

What are the different objects that you cannot copy or reference in object groups?

Description : What are the different objects that you cannot copy or reference in object groups?

Last Answer : Objects of different modules Another object groups Individual block dependent items Program units.

If the maximum record retrieved property of the query is set to 10 then a summary value will be calculated?

Description : If the maximum record retrieved property of the query is set to 10 then a summary value will be calculated?

Last Answer : Only for 10 records.

Are there any undocumented commands in Oracle? (for DBA

Description : Are there any undocumented commands in Oracle? (for DBA

Last Answer : 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 ... rdbms/lib/oradbx.o; make -f oracle.mk oradbx) SQL*Plus: ALTER SESSION SET CURRENT_SCHEMA = SYS;

What is the OPTIMAL parameter?

Description : What is the OPTIMAL parameter?

Last Answer : How does one use ORADEBUG from Server Manager/ SQL*Plus? (for DBA

What is the use of TABLES option in EXP command ?

Description : What is the use of TABLES option in EXP command ?

Last Answer : List of tables should be exported.ze)

What is the use of PARFILE option in EXP command ?

Description : What is the use of PARFILE option in EXP command ?

Last Answer : Name of the parameter file to be passed for export.

What is the difference between DBFile Sequential and Scattered Reads?(for DBA

Description : What is the difference between DBFile Sequential and Scattered Reads?(for DBA

Last Answer : Both "db file sequential read" and "db file scattered read" events signify time waited for I/O read requests to complete. Time is reported in 100's of a second for Oracle 8i releases and below, ... v_$system_event b where a.event = 'db file sequential read' and b.event = 'db file scattered read';

How does one tune Oracle Wait events? (for DBA

Description : How does one tune Oracle Wait events? (for DBA

Last Answer : Some wait events from V$SESSION_WAIT and V$SYSTEM_EVENT views: Event Name: Tuning Recommendation: db file sequential read Tune SQL to do less I/O. Make sure all objects are analyzed. Redistribute ... SYS.V$BH log buffer spaces Increase LOG_BUFFER parameter or move log files to faster disks