What is Log Switch? – The detect at which ORACLE ends composition to everybody online redo log complete and begins composition to another is called a log thrash. What is On-line Redo Log? – The On-line Redo Log is a jaded out of footpath or more on-line redo files that notation all committed changes made to the database. Whenever a deal is committed, the corresponding redo entries for a short stores in redo log buffers of the SGA are written to an on-line redo log complete over the circumstance course of action LGWR. The on-line redo log files are old in cyclical the fad. When objects are created their INITIAL and MINEXTENS values cannot be changed. Which parameter specified in the DEFAULT STORAGE clause of CREATE TABLESPACE cannot be altered after creating the tablespace? – All the collapse storage parameters defined looking for the tablespace can be changed using the ALTER TABLESPACE look down on. What are the steps affected in Database Startup? – Start an event, Mount the Database andOpen the Database.
What are the steps affected in Instance Recovery? – Rolling into the unsigned to improve statistics that has not been recorded in statistics files, besides has been recorded in the on-line redo log, including the contents of rollback segments. Releasing any resources (locks) held over transactions in course of action at the previously of the collapse. Rolling with have knowledge of transactions that include been explicitly rolled with have knowledge of or include not been committed as indicated over the rollback segments regenerated in eccentric a.
Resolving any unconfirmed distributed transactions undergoing a two-phase swear at the previously of the event collapse. Can Full Backup be performed when the database is unsigned? – No. Parallel Mode If the higher- ranking event that mounts a database is started in equate to phrasing, other instances that are started in equate to phrasing can also mount the database. What are the bizarre modes of mounting a Database with the Parallel Server? – Exclusive Mode If the higher- ranking event that mounts a database does so in choice phrasing, not that Instance can mount the database. What are the advantages of operating a database in ARCHIVELOG phrasing left over operating it in NO ARCHIVELOG phrasing? – Complete database advance from disk collapse is imaginable not in ARCHIVELOG phrasing.
Online database backup is imaginable not in ARCHIVELOG phrasing. What is Archived Redo Log? – Archived Redo Log consists of Redo Log files that include archived earlier to being reused. What are the steps affected in Database Shutdown? – Close the Database, Dismount the Database and Shutdown the Instance. What is Restricted Mode of Instance Startup? – An event can be started in (or later altered to be in) restricted phrasing so that when the database is unsigned connections are exiguous not to those whose alcohol accounts include been granted the RESTRICTED SESSION structure benefit.
What is Partial Backup? – A Partial Backup is any operating structure backup impecunious of a crammed backup, infatuated while the database is unsigned or coop up down. What is Full Backup? – A crammed backup is an operating structure backup of all statistics files, on- face redo log files and check complete that constitute ORACLE database and the parameter. What is Mirrored on-line Redo Log? – A mirrored on-line redo log consists of copies of on-line redo log files physically located on break up disks, changes made to everybody fellow of the assemble are made to all members. Can a View based on another View? – Yes. Can a Tablespace contain objects from bizarre Schemes? – Yes. What is the employment of Control File? – When an event of an ORACLE database is started, its ontrol complete is old to make clear gratitude the database and redo log files that desideratum be opened looking for database man to proceed.
Can objects of the even so Schema reside in bizarre tablespaces? – Yes. It is also old in database advance. Do View contain back Data? – Views do not contain back or aggregate statistics. DELETE Cascade – When a referenced line is deleted all associated dependent rows are deleted.
What are the Referential actions supported over FOREIGN KEY decency constraint? – UPDATE and DELETE Restrict – A referential decency law that disallows the update or deletion of referenced statistics. What are the classification of Synonyms? – There are two types of Synonyms Private and Public What is a Redo Log? – The jaded out of Redo Log files YSDATE,UID,USER or USERENV SQL functions, or the pseudo columns LEVEL or ROWNUM. What is an Index Segment? – Each Index has an Index division that stores all of its statistics. What are Clusters? – Clusters are groups of everybody or more tables physically stores together to share in unexceptional columns and are day in and day manifest old together. Explain the relationship amongst Database, Tablespace and Data complete.? – Each databases logically divided into everybody or more tablespaces everybody or more statistics files are explicitly created looking for each tablespace What are the bizarre classification of Segments? – Data Segment, Index Segment, Rollback Segment and Temporary Segment. What is an Integrity Constrains? – An decency constraint is a declarative mode to circumscribe a affair law looking for a column of a tabular.
What is an Index? – An Index is an non-mandatory form associated with a tabular to include poor dumping-ground access to rows, which can be created to expand the conduct of statistics retrieval. What is an Extent? – An Extent is a together to hundred of contiguous statistics blocks, obtained in a isolated allocation, and old to aggregate a together to classification of poop. Index can be created on everybody or more columns of a tabular. What is a View? – A judge is a essential tabular.
Every judge has a Query joined to it. The tables of a database contain all of the alcohol approachable statistics. (The Query is a SELECT asseveration that identifies the columns and rows of the table(s) the judge uses.) What is Table? – A tabular is the indicator item of statistics storage in an ORACLE database.
Table statistics is stored in rows and columns. What is a Synonym? – A synonym is an alias looking for a tabular, judge, structure or program item. What is a Segment? – A division is a jaded out of extents allocated looking for a credible rational form. What is a Sequence? – A structure generates a serial catalogue of together numbers looking for numerical columns of a database’s tables. What is schema? – A schema is accumulation of database objects of a User. Describe Referential Integrity? – A law defined on a column (or jaded out of columns) in everybody tabular that allows the circular or update of a line not if the value looking for the column or jaded out of columns (the dependent value) matches a value in a column of a consanguineous tabular (the referenced value). What is Hash Cluster? – A line is stored in a botch bunch based on the fruit of applying a botch call to the row’s bunch indicator value.
It also specifies the classification of statistics manipulation allowed on referenced statistics and the counteraction manifest to be performed on dependent statistics as a fruit of any counteraction manifest on referenced statistics. All rows with the even so botch indicator value are stores together on disk. What is a Private Synonyms? – A Private Synonyms can be accessed not over the possessor.
What is a Tablespace? – A database is divided into Logical Storage Unit called tablespaces. What is Database Link? – A database fasten is a named game that describes a path from everybody database to another. A tablespace is old to grouped consanguineous rational structures together What is Rollback Segment? – A Database contains everybody or more Rollback Segments to for a short aggregate undo poop. What are the Characteristics of Data Files? – A statistics complete can be associated with not everybody database. One or more statistics files figure a rational item of database storage called a tablespace.
Once created a statistics complete can’t thrash bigness. How to circumscribe Data Block bigness? – A statistics qualify bigness is specified looking for each ORACLE database when the database is created. A database users and allocated released database margin in ORACLE datablocks. What does a Control complete Contain? – A Control complete records the manifest form of the database. Block bigness is specified in INIT.ORA complete and can’t be changed latter. It contains the following poop. Database Name Names and locations of a database’s files and redolog files.
What is metamorphosis between UNIQUE constraint and PRIMARY KEY constraint? – A column defined as UNIQUE can contain back Nulls while a column defined as PRIMARY KEY can’t contain back Nulls. Time squelch of database start. 47.What is Index Cluster? – A Cluster with an poise on the Cluster Key on the strong. When does a Transaction fruit? – When it is committed or Rollbacked. What is the figure of environment the value ALL_ROWS looking for OPTIMIZER_GOAL parameter of the ALTER SESSION look down on? – What are the factors that have reference to OPTIMIZER in choosing an Optimization thunder-shower a plot to? – Answer The OPTIMIZER_MODE initialization parameter Statistics in the Data Dictionary the OPTIMIZER_GOAL parameter of the ALTER SESSION look down on hints in the asseveration.