Answer:- The five types of SQL statements are as follows: • DDL: Data definition language (DDL) helps in the creation of a database structure or schema. CREATE, DROP, ALTER, RENAME, and TRUNCATE are the five types of DDL commands in SQL. • DML: Data manipulation language (DML) allows you to insert, change, and delete data from a database instance. DML is in charge of making all kinds of changes to a database’s data. The database application and the user can insert data and information using three basic commands—INSERT, UPDATE, and DELETE. • DCL: GRANT and REVOKE are the commands in the data control language (DCL) that can be used to grant rights and permissions. The database system’s parameters are controlled by other permissions. • TCL: Transaction control language (TCL) commands deal with database transactions. Some of the TCL commands are COMMIT, ROLLBACK, and SAVEPOINT. • DQL: Data query language (DQL) is used to retrieve data from the database. It just has one command, which is SELECT.

Answer:- Tracing the code is a crucial technique to measure its performance during the runtime. The different methods of tracing the code include: • DBMS_APPLICATION_INFO • DBMS_TRACE • DBMS_SESSION and DBMS_MONITOR • trcsess and tkprof utilities

Answer:- There are three types of parameters in PL/SQL. They are as follows: • IN: The IN parameter allows you to send values to the procedure that is being called. The IN parameter can be set to default values. It behaves as a constant and cannot be changed. • OUT: The OUT parameter returns a value to the caller. The OUT parameter is an uninitialized variable that cannot be used in expressions. • IN OUT: The IN OUT parameter sends starting values to a procedure and returns the updated values to the caller. This parameter should be treated as an initialized variable and given a value.

Answer:- PL/SQL records are a collection of values. To put it another way, PL/SQL records are a collection of many pieces of information, each of which is of a simpler type and can be associated with one another as fields. Three types of records are supported in PL/SQL: • Records based on tables • Records created by programmers • Records that are based on a cursor

Answer:- We use an index in a table to allow quick access to rows. For procedures that return a small percentage of a table’s rows, an index allows quicker access to data.

Answer:- • Functions: The main purpose of PL/SQL functions is to compute and return a single value. The functions have a return type in their specifications and must return a specified value in that type. • Procedures: Procedures do not have a return type and should not return any value, but they can have a return statement that simply stops its execution and returns to the caller. Procedures are used to return multiple values; otherwise, they are generally similar to functions. • Packages: Packages are schema objects that group logically related PL/SQL types, items, and subprograms. You can also say that packages are a group of functions, procedures, variables, and record TYPE statements. Packages provide modularity, which aids in application development. Packages are used to hide information from unauthorized users.

Answer:- Database links are used to establish communication across multiple databases or environments such as test, development, and production. Other information can also be accessed using database links, which are read-only.

Answer:- A stored procedure is a sequence of statements or a named PL/SQL block that performs one or more specific functions. It is similar to a procedure in other programming languages. It is stored in the database and can be repeatedly executed. It is stored as a schema object and can be nested, invoked, and parameterized.

Answer:- When the name of the same procedure is repeated with the parameters of different data types and parameters in different places, then that is referred to as procedure overloading.

Answer:- Expressions are made up of a series of literals and variables that are separated by operators. Operators are used in PL/SQL to manipulate, compare, and calculate data. Expressions are made up of two parts, operators and operands.

Answer:- The statement’s result is saved in four cursor attributes. The four attributes are: • SQL% FOUND • SQL% NOTFOUND • SQL% ROWCOUNT • SQL% ISOPEN

Answer:- A cursor is a temporary work area that is created in system memory when an SQL statement is executed. A cursor contains information on a select statement and the row of data accessed by it. This temporary work area stores the data, which is retrieved from the database, to manipulate it. A cursor can hold more than one row but can process only one row at a time. A cursor is required to process rows individually for queries.

Answer:- There are two types of cursors: • Implicit Cursor: When PL/SQL executes an SQL statement, it automatically constructs a cursor without specifying one; these cursors are known as implicit PL/SQL uses implicit cursors for the following statements: • INSERT • UPDATE • DELETE • SELECT • Explicit Cursor: A programmer declares and names an explicit cursor for the queries that return more than one row. An explicit cursor is a SELECT statement that is declared explicitly in the current block’s declaration section or in a package definition. The following are the commands that are used for explicit cursors in PL/SQL: • OPEN • FETCH • CLOSE

Answer:- When the OPEN cursor command is used to open a cursor, it performs the following operations: • Set aside a processing memory region • Paese the statement SELECT • Use the memory addresses to assign values to input variables • Recognize the active set of rows that meet the selection criteria • Place the pointer exactly before the active set’s first row