Table of Contents
What is the use of collections in Oracle?
To use collections in an application, you define one or more PL/SQL types, then define variables of those types. You can define collection types in a procedure, function, or package. You can pass collection variables as parameters to stored subprograms.
How can I use a collection within an Oracle SQL statement?
This means you need to declare your TYPE in SQL. Then you can use it in a SELECT statement: SELECT Name INTO MyName FROM Item WHERE ItemId NOT IN (select * from table(MyList)); Of course, you need to make sure that your query returns only one row, or that your program handles the TOO_MANY_ROWS exception.
What is dense and sparse in Oracle collection?
Dense: If all the rows between the first and last are defined and given a value (including NULL) Sparse: Not defined or populated sequentially. There are gaps between defined rows. VARRAYS are always dense as we cannot delete values in between and the values can only be deleted from the end (using TRIM).
What is the difference between ASO and BSO cubes?
BSO cubes typically contain fewer (and smaller) dimensions than aggregate storage (ASO) cubes and can perform numerous and complex calculations on the smaller outlines.
What is the difference between sparse and dense index?
Dense Index: It has index entries for every search key value (and hence every record) in the database file. The dense index can be built on order as well as unordered fields of the database files. Sparse Index: It has index entries for only some of the search key values/records in the database file.
What are the different collection types in PL/SQL?
PL/SQL offers these collection types: Associative arrays, also known as index-by tables, let you look up elements using arbitrary numbers and strings for subscript values. These are similar to hash tables in other programming languages. Nested tables hold an arbitrary number of elements. They use sequential numbers as subscripts.
How many types of collections are there in Oracle?
Oracle provides three basic collections, each with an assortment of methods. This article was originally written against Oracle 8i, but it includes operators, conditions and functions that were added in later releases. Related articles. The first type of collection is known as index-by tables.
What are the different types of collection data types?
Many programming techniques use collection types such as arrays, bags, lists, nested tables, sets, and trees. You can model these types in database applications using the PL/SQL datatypes TABLE and VARRAY, which allow you to declare nested tables, associative arrays, and variable-size arrays.
Can you create a collection of objects in a table?
In addition to collections of scalar or object types, you can also create collections whose elements are collections. For example, you can create a nested table of varrays, a varray of varrays, a varray of nested tables, and so on.