oracle database 12c new features

Oracle PL/SQL Programming

Oracle Database 12c Release 1 PL/SQL New Features

Steven Feuerstein PL/SQL Evangelist, Dell

[email protected]


Copyright 2013 Feuerstein and Associates

How to benefit most from this presentation

• Watch, listen, ask questions, focus on concepts and principles.

• Download and use any of my training materials:

You have my permission to use all these materials to do internal trainings and build your own applications. – But remember: they are not production ready.

– You must test them and modify them to fit your needs.

12c*_filename_from_demo_zip.sql

Download and use any of my scripts (examples, performance scripts, reusable code) from the same location: the demo.zip file.

http://www.ToadWorld.com/SF PL/SQL Obsession



Lots of Goodies for PL/SQL Developers

• More PL/SQL-Only Data Types Cross PL/SQL-to-SQL Interface

• Optimizing Function Execution in SQL • The UTL_CALLSTACK Package • The ACCESSIBLE_BY Clause • FETCH FIRST and BULK COLLECT • Privileges/Access Management for Program Units

– Grant Roles to Program Units – And INHERIT PRIVILEGES and INHERIT ANY PRIVILEGES – BEQUEATH CURRENT_USER for Views

• New Conditional Compilation Directives • Implicit Statement Results • Goodbye, Tiny SQL VARCHAR2!



More PL/SQL-Only Data Types Cross PL/SQL-to-SQL Interface

• Prior to 12c, PL/SQL-only datatypes could not be bound in dynamic SQL statements, restricted what functions could be called in SQL, etc.

• Now, those rules are greatly relaxed.

– Bind records and associative arrays

– Use TABLE operator with associative arrays

– Still can't do much with Booleans

12c_table*.sql 12c_bind*.sql



Optimizing Function Execution in SQL

• That seems like an awfully good idea!

• Two methods:

– WITH clause that defines a function

– UDF pragma that gives more options to the compiler

• WITH FUNCTION: define a function directly within your SQL statement.

– Say goodbye to nasty context switch!

12c_with_function*.sql 12c_udf.sql & 12c_udf2.sql



The UTL_CALLSTACK Package

• Prior to 12c, you could obtain several kinds of "stacks" through individual function calls: – DBMS_UTILITY.FORMAT_CALL_STACK - "How did I

get here?"

– DBMS_UTILITY.FORMAT_ERROR_STACK - "What is the error message/stack?"

– DBMS_UTILITY.FORMAT_ERROR_BACKTRACE - "On what line was my error raised?"

• Now, the UTL_CALLSTACK package supports all that and a much better API to the info in the stack.

12c_utl_callstack*.sql



FETCH FIRST N for BULK COLLECT

• BULK COLLECT now supports an optional FETCH FIRST clause.

– Limits the number of rows that a query returns, reducing the complexity of common "Top-N" queries.

• FETCH FIRST is provided primarily to simplify migration from third-party databases to Oracle Database.

12c_fetch_first.sql



The ACCESSIBLE_BY Clause

• ACCESSIBLE_BY extends the concept of "privacy" for package subprograms.

• Use it to define a "whitelist" of program units that can invoke a package's subprograms.

12c_accessible_by.sql

PACKAGE private_pkg ACCESSIBLE BY (public_pkg) IS PROCEDURE do_this; PROCEDURE do_that; END;

PACKAGE BODY public_pkg IS PROCEDURE do_only_this IS BEGIN private_pkg.do_this; private_pkg.do_that; END; END;



Grant Roles to Program Units

• You can now grant roles to program units, so you fine-tune the privileges available to the invoker of a program unit. – Helpful when you don't want the invoker to inherit all of

the definer's privileges.

• Roles granted to a program unit do not affect compilation. – Instead, they affect the privilege checking of SQL

statements that the unit issues at run time. – So the program unit executes with the privileges of both its

own roles and any other currently enabled roles.

• Most helpful when the program unit executes dynamic SQL (no privilege checking till runtime).

invdefinv.sql 12c_grant_roles_units.sql

12c_roles_for_program_units.sql



BEQUEATH CURRENT_USER for Views

• Prior to 12.1, if your view executed a function, it would always be run under the privileges of the view's owner, and not that of the function.

– Even if the function was defined with AUTHID CURRENT_USER

• Add the BEQUEATH CURRENT_USER clause and then the invoker right's mode of the function will be "honored."

12c_bequeath.sql



INHERIT PRIVILEGES and INHERIT ANY PRIVILEGES

• More fine-tuning for privilege management!

• You can override AUTHID and BEQUEATH settings by revoking INHERIT PRIVILEGES.

– On a schema-level basis

• You can say, in effect: "All schemas but SCOTT can use my privileges when running X."

• After upgrade, all works as before.

– INHERT PRIVILEGES granted to all schemas

12c_inherit_privileges.sql



New Conditional Compilation Directives

• Oracle has added two new directives.

• $$PLSQL_UNIT_OWNER

– Returns the name of the owner of the current program unit. Returns NULL if an anonymous block.

• $$PLSQL_UNIT_TYPE

– Returns the type of the program unit

– Inside an anonymous block or non-DML trigger, returns "ANONYMOUS BLOCK".



Implicit Statement Results

• I hate when a SQL Server developer says "Ha, ha, I can do this and you can't."

• Well, with 12.1, there's one less thing that developer can talk about.

– Not that there was ever all that much….

• We can now create a procedure that will implicitly display the result of a SQL statement.

– And it breathes some life back into DBMS_SQL!

12c_implicit_results.sql



Goodbye, Tiny SQL VARCHAR2!

• It sure has been irritating that PL/SQL supports VARCHAR2s up to 32K in size (after which , you must switch over to CLOBs), while in SQL, the maximum was 4000.

• Now, SQL's VARCHAR2 and NVARCHAR2 have been extended to 32K as well!

• Note: SQL has these maximum sizes only if the MAX_STRING_SIZE initialization parameter is set to EXTENDED.

12c_sql_varchar2.sql



Oracle12c New PL/SQL Features

• Nothing earth-shattering, but a solid improvement on an already robust language.

– Improved integration with SQL

– Better support for migration from TransactSQL and other database languages

– Fine-tuning of privileges management and access control.

• My favorite by far: ability to use TABLE with associative arrays.

oracle database 12c new features

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