What are collections in PL SQL?
A collection is an ordered group of elements having the same data type. Each element is identified by a unique subscript that represents its position in the collection.
What are the different types of collections in Oracle?
PL/SQL has three collection types—associative array, VARRAY (variable-size array), and nested table.
What are Oracle collections?
A Collection is an ordered group of elements of particular data types. It can be a collection of simple data type or complex data type (like user-defined or record types). In the collection, each element is identified by a term called “subscript.” Each item in the collection is assigned with a unique subscript.
What is the difference between PL SQL function and PL SQL procedure?
Procedures are basic PL SQL blocks to perform a specific action. Functions are blocks used mainly to perform the computations. Functions must return the value. When you are writing functions make sure that you can write the return statement.
What is the difference between nested table and Varray?
Differences Between Varrays And Nested Tables A Varray which is stored in a database maintains its subscripts and sequence. It is always maintained as a single object. Whereas, the nested tables are used when the count of the number of elements is not restricted.
How many types of tables are there in Oracle?
1.1 About Table Types. The most common type of table in an Oracle database is a relational table, which is structured with simple columns similar to the employees table. Two other table types are supported: object tables and XMLType tables. Any of the three table types can be defined as permanent or temporary.
What is the difference between record and collection in Oracle?
What are PL/SQL Collections and Records? Collections and records are composite types that have internal components that can be manipulated individually, such as the elements of an array, record, or table. A collection is an ordered group of elements, all of the same type.
What are the different types of loops in Plsql?
PL/SQL provides four kinds of loop statements: basic loop, WHILE loop, FOR loop, and cursor FOR loop.
What is difference between package and procedure in Oracle?
A package can contain no procedures or functions. It may just contain data types or global variables. 2. A procedure does not return any values in itself, however it can have parameters that can be used to return values as either OUT or modify (IN/OUT).
What is difference between procedure and stored procedure?
The function must return a value but in Stored Procedure it is optional. Even a procedure can return zero or n values. Functions can have only input parameters for it whereas Procedures can have input or output parameters. Functions can be called from Procedure whereas Procedures cannot be called from a Function.
What is the difference between bulk collect and forall?
BULK COLLECT: These are SELECT statements that retrieve multiple rows with a single fetch, thereby improving the speed of data retrieval. FORALL: These are INSERT, UPDATE, and DELETE operations that use collections to change multiple rows of data very quickly.
Why collections are used in Oracle?
Storing elements in a collection can provide a number of advantages. For starters, collections can help to simplify code. If you need to process a number of items of a similar type, storing these items in a collection will allow you to loop through each element with ease, referencing each one by an index.
What are the different types of collections in PL/SQL?
The PL/SQL collections are of 3 types which are given below with syntax: 1. Nested tables A nested table is a PL/SQL collection in which the size is not fixed. So, it is like a one-dimensional array except for the fact that the size is fixed in arrays and it can be dense and sparse both.
What are the advantages of PL/SQL collection?
The PL/SQL collection provides a lot of advantages to both the programmer and the user while storing and accessing the data of similar data types in an application. When there is a need to process the data all at once or handling a large amount of data, PL/SQL collections are very useful.
What is a collection in Oracle?
A collection is an ordered group of elements having the same data type. Each element is identified by a unique subscript that represents its position in the collection. Oracle documentation provides the following characteristics for each type of collections − We have already discussed varray in the chapter ‘PL/SQL arrays’.
What are the equivalent types in PL/SQL?
The equivalent types in PL/SQL can all be referred to as “collections”, and PL/SQL provides three of them: Now although this is all mentioned in the documentation, and there are many articles and blogs that more or less repeat the documentation (and unhelpfully invent new terms like “Associative Table” ), I see two problems: