What Are The Types Of Sql Statement?
Data Definition Language: CREATE, ALTER, DROP, TRUNCATE, REVOKE, NO AUDIT & COMMIT.
Data Manipulation Language: INSERT, UPDATE, DELETE, LOCK TABLE, EXPLAIN PLAN & SELECT.
Transactional Control: COMMIT & ROLLBACK.
Session Control: ALTERSESSION & SET ROLE.
System Control: ALTER SYSTEM.
What Is An Oracle Sequence?
A sequence generates a serial list of unique numbers for numerical columns of a database’s tables.
What Is System Tablespace And When Is It Created?
Every Oracle database contains a tablespace named SYSTEM, which is automatically created when the database is created. The SYSTEM tablespace always contains the data dictionary tables for the entire database.
What Is A Tablespace?
A database is divided into Logical Storage Unit called tablespaces. A tablespace is used to grouped related logical structures together.
What Are The Components Of Logical Database Structure Of Oracle Database?
There are tablespaces and database’s schema objects.
What Are The Components Of Physical Database Structure Of Oracle Database?
Oracle database is comprised of three types of files. One or more datafiles, two are more redo log files, and one or more control files.
What Are The Dictionary Tables Used To Monitor A Database Space?
DBA_FREE_SPACE
DBA_SEGMENTS
DBA_DATA_FILES.
SQL*Plus Statements
How Will You Enforce Security Using Stored Procedures?
Don’t grant user access directly to tables within the application.
Instead grant the ability to access the procedures that access the tables.
When procedure executed it will execute the privilege of procedures owner. Users cannot access tables except via the procedure.
What Is User Account In Oracle Database?
A user account is not a physical structure in database but it is having important relationship to the objects in the database and will be having certain privileges.
List The Factors That Can Affect The Accuracy Of The Estimations?
- The space used transaction entries and deleted records, does not become free immediately after completion due to delayed cleanout.
- Trailing nulls and length bytes are not stored.
- Inserts of, updates to and deletes of rows as well as columns larger than a single data block, can cause fragmentation a chained row pieces.
What Is A Public Synonym?
Any database user can access a public synonym.
What Is A Private Synonym?
Only its owner can access a private synonym.
What Are The Types Of Synonyms?
There are two types of synonyms private and public.
What Is A Synonym?
A synonym is an alias for a table, view, sequence or program unit.
What Is The Significance Of Having Storage Clause?
We can plan the storage for a table as how much initial extents are required, how much can be extended next, how much % should leave free for managing row updating, etc.,
Which Parameter In Storage Clause Will Reduce Number Of Rows Per Block?
PCTFREE parameter
Row size also reduces no of rows per block.
What Is Meant By Free Extent?
A free extent is a collection of continuous free blocks in tablespace. When a segment is dropped its extents are reallocated and are marked as free.
How Will You Force Database To Use Particular Rollback Segment?
SET TRANSACTION USE ROLLBACK SEGMENT rbs_name.
List The Optional Flexible Architecture (ofa) Of Oracle Database? How Can We Organize The Tablespaces In Oracle Database To Have Maximum Performance?
SYSTEM – Data dictionary tables.
DATA - Standard operational tables.
DATA2- Static tables used for standard operations
INDEXES – Indexes for Standard operational tables.
INDEXES1 – Indexes of static tables used for standard operations.
TOOLS – Tools table.
TOOLS1 – Indexes for tools table.
RBS – Standard Operations Rollback Segments,
RBS1,RBS2 – Additional/Special Rollback segments.
TEMP – Temporary purpose tablespace
TEMP_USER – Temporary tablespace for users.
USERS – User tablespace.
How Will You Swap Objects Into A Different Table Space For An Existing Database?
- Export the user
- Perform import using the command imp system/manager file=export.dmp indexfile=newrite.sql. This will create all definitions into newfile.sql.
- Drop necessary objects.
- Run the script newfile.sql after altering the tablespaces.
- Import from the backup for the necessary objects.
What Is An Index? How It Is Implemented In Oracle Database?
An index is a database structure used by the server to have direct access of a row in a table. An index is automatically created when a unique of primary key constraint clause is specified in create table command
What Is A Schema?
The set of objects owned by user account is called the schema.
What Is Parallel Server?
Multiple instances accessing the same database (only in multi-CPU environments)
What Is A Database Instance? Explain.
A database instance (Server) is a set of memory structure and background processes that access a set of database files. The processes can be shared by all of the users.
The memory structure that is used to store the most queried data from database. This helps up to improve database performance by decreasing the amount of I/O performed against data file.
What Is The Use Of Control File?
When an instance of an Oracle database is started, its control file is used to identify the database and redo log files that must be opened for database operation to proceed. It is also used in database recovery.
What Does A Control File Contains?
- Database name
- Names and locations of a database’s files and redolog files.
- Time stamp of database creation.
What Is Row Chaining?
In circumstances, all of the data for a row in a table may not be able to fit in the same data block. When this occurs, the data for the row is stored in a chain of data block (one or more) reserved for that segment.
Data Definition Language: CREATE, ALTER, DROP, TRUNCATE, REVOKE, NO AUDIT & COMMIT.
Data Manipulation Language: INSERT, UPDATE, DELETE, LOCK TABLE, EXPLAIN PLAN & SELECT.
Transactional Control: COMMIT & ROLLBACK.
Session Control: ALTERSESSION & SET ROLE.
System Control: ALTER SYSTEM.
What Is An Oracle Sequence?
A sequence generates a serial list of unique numbers for numerical columns of a database’s tables.
What Is System Tablespace And When Is It Created?
Every Oracle database contains a tablespace named SYSTEM, which is automatically created when the database is created. The SYSTEM tablespace always contains the data dictionary tables for the entire database.
What Is A Tablespace?
A database is divided into Logical Storage Unit called tablespaces. A tablespace is used to grouped related logical structures together.
What Are The Components Of Logical Database Structure Of Oracle Database?
There are tablespaces and database’s schema objects.
What Are The Components Of Physical Database Structure Of Oracle Database?
Oracle database is comprised of three types of files. One or more datafiles, two are more redo log files, and one or more control files.
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What Are The Dictionary Tables Used To Monitor A Database Space?
DBA_FREE_SPACE
DBA_SEGMENTS
DBA_DATA_FILES.
SQL*Plus Statements
How Will You Enforce Security Using Stored Procedures?
Don’t grant user access directly to tables within the application.
Instead grant the ability to access the procedures that access the tables.
When procedure executed it will execute the privilege of procedures owner. Users cannot access tables except via the procedure.
What Is User Account In Oracle Database?
A user account is not a physical structure in database but it is having important relationship to the objects in the database and will be having certain privileges.
List The Factors That Can Affect The Accuracy Of The Estimations?
- The space used transaction entries and deleted records, does not become free immediately after completion due to delayed cleanout.
- Trailing nulls and length bytes are not stored.
- Inserts of, updates to and deletes of rows as well as columns larger than a single data block, can cause fragmentation a chained row pieces.
Any database user can access a public synonym.
What Is A Private Synonym?
Only its owner can access a private synonym.
What Are The Types Of Synonyms?
There are two types of synonyms private and public.
What Is A Synonym?
A synonym is an alias for a table, view, sequence or program unit.
What Is The Significance Of Having Storage Clause?
We can plan the storage for a table as how much initial extents are required, how much can be extended next, how much % should leave free for managing row updating, etc.,
Which Parameter In Storage Clause Will Reduce Number Of Rows Per Block?
PCTFREE parameter
Row size also reduces no of rows per block.
What Is Meant By Free Extent?
A free extent is a collection of continuous free blocks in tablespace. When a segment is dropped its extents are reallocated and are marked as free.
How Will You Force Database To Use Particular Rollback Segment?
SET TRANSACTION USE ROLLBACK SEGMENT rbs_name.
List The Optional Flexible Architecture (ofa) Of Oracle Database? How Can We Organize The Tablespaces In Oracle Database To Have Maximum Performance?
SYSTEM – Data dictionary tables.
DATA - Standard operational tables.
DATA2- Static tables used for standard operations
INDEXES – Indexes for Standard operational tables.
INDEXES1 – Indexes of static tables used for standard operations.
TOOLS – Tools table.
TOOLS1 – Indexes for tools table.
RBS – Standard Operations Rollback Segments,
RBS1,RBS2 – Additional/Special Rollback segments.
TEMP – Temporary purpose tablespace
TEMP_USER – Temporary tablespace for users.
USERS – User tablespace.
How Will You Swap Objects Into A Different Table Space For An Existing Database?
- Export the user
- Perform import using the command imp system/manager file=export.dmp indexfile=newrite.sql. This will create all definitions into newfile.sql.
- Drop necessary objects.
- Run the script newfile.sql after altering the tablespaces.
- Import from the backup for the necessary objects.
An index is a database structure used by the server to have direct access of a row in a table. An index is automatically created when a unique of primary key constraint clause is specified in create table command
What Is A Schema?
The set of objects owned by user account is called the schema.
What Is Parallel Server?
Multiple instances accessing the same database (only in multi-CPU environments)
What Is A Database Instance? Explain.
A database instance (Server) is a set of memory structure and background processes that access a set of database files. The processes can be shared by all of the users.
The memory structure that is used to store the most queried data from database. This helps up to improve database performance by decreasing the amount of I/O performed against data file.
What Is The Use Of Control File?
When an instance of an Oracle database is started, its control file is used to identify the database and redo log files that must be opened for database operation to proceed. It is also used in database recovery.
What Does A Control File Contains?
- Database name
- Names and locations of a database’s files and redolog files.
- Time stamp of database creation.
What Is Row Chaining?
In circumstances, all of the data for a row in a table may not be able to fit in the same data block. When this occurs, the data for the row is stored in a chain of data block (one or more) reserved for that segment.