What is ref cursor example?

What is ref cursor example?

A ref cursor is a variable, defined as a cursor type, which will point to, or reference a cursor result. The advantage that a ref cursor has over a plain cursor is that is can be passed as a variable to a procedure or a function. The REF CURSOR can be assigned to other REF CURSOR variables.

What is a cursor data type?

There are two main types of cursor data types: weakly-typed cursor data types and strongly-typed cursor data types. The property of being strongly or weakly typed is defined when the data type is created. Cursor data type result set definitions can be defined by providing a row type definition.

What is ref cursor and its typeS?

A cursor variable is a variable that references to a cursor. Different from implicit and explicit cursors, a cursor variable is not tied to any specific query. To declare a cursor variable, you use the REF CURSOR is the data type. PL/SQL has two forms of REF CURSOR typeS: strong typed and weak typed REF CURSOR .

Is ref cursor can be used for dynamic queries?

Answer: Here is an example script that performs dynamic SQL and returns the data as a ref cursor. …

What is ref cursor in PostgreSQL?

Declaring cursors PostgreSQL provides you with a special type called REFCURSOR to declare a cursor variable. Then, you put the CURSOR keyword followed by a list of comma-separated arguments ( name datatype ) that defines parameters for the query. These arguments will be substituted by values when the cursor is opened.

What is strong ref cursor in Oracle?

A ref cursor which has fixed return type is called a Strong Ref Cursor in Oracle Database. Because of fixed return type, strong ref cursors can only be used selectively. For instance with those SELECT statements that return the result whose datatype matches with the one that you have fixed during cursor’s declaration.

Does ref cursor increase performance?

The next performance-related advantage of a regular cursor is also an ease-of-use feature. A regular cursor can implicitly array-fetch 100 rows at a time, whereas a ref cursor must use explicit array fetching. In other words, a regular cursor can more efficiently retrieve data by using significantly less code.

Which is faster in or exists?

The EXISTS clause is much faster than IN when the subquery results is very large. Conversely, the IN clause is faster than EXISTS when the subquery results is very small. Also, the IN clause can’t compare anything with NULL values, but the EXISTS clause can compare everything with NULLs.

When to use Ref cursors to return recordsets?

Using Ref Cursors To Return Recordsets. Since Oracle 7.3 the REF CURSOR type has been available to allow recordsets to be returned from stored procedures and functions. Oracle 9i introduced the predefined SYS_REFCURSOR type, meaning we no longer have to define our own REF CURSOR types.

What does a REF CURSOR do in Oracle?

Using REF CURSORs is one of the most powerful, flexible, and scalable ways to return query results from an Oracle Database to a client application. A REF CURSOR is a PL/SQL data type whose value is the memory address of a query work area on the database. In essence, a REF CURSOR is a pointer or a handle to a result set on the database.

Which is an example of a weak typed REF CURSOR?

And here is an example of a weak typed REF CURSOR declaration that is not associated with any specific structure: Starting from Oracle 9i, you can use SYS_REFCURSOR, which is a predefined weak typed REF CURSOR, to declare a weak REF CURSOR as follows:

Can you convert ref cursors to DBMS _ SQL?

Oracle 11g allows the two-way conversion between ref cursors to DBMS_SQL cursors, as described here. Oracle 12c allows implicit statements results, similar to that seen in Transact-SQL, as described here. For more information see: Hope this helps. Regards Tim…