Oracle Database 12c Release 1 PL/SQL New Features

Transcription

1 Oracle Database 12c Release 1 PL/SQL New Features Steven Feuerstein PL/SQL Evangelist, Dell steven@stevenfeuerstein.com

2 How to benefit most from this presentation Watch, listen, ask questions, focus on concepts and principles. Download and use any of my training materials: PL/SQL Obsession Download and use any of my scripts (examples, performance scripts, reusable code) from the same location: the demo.zip file. 12c*_filename_from_demo_zip.sql 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. Copyright 2013 Feuerstein and Associates Page 2

3 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! Copyright 2013 Feuerstein and Associates Page 3

4 More PL/SQL-Only Data Types Cross PL/SQL-to-SQL Interface Oracle PL/SQL Programming 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 Copyright 2013 Feuerstein and Associates Page 4

5 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 Copyright 2013 Feuerstein and Associates Page 5

6 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 Copyright 2013 Feuerstein and Associates Page 6

7 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 Copyright 2013 Feuerstein and Associates Page 7

8 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. PACKAGE BODY public_pkg IS PROCEDURE do_only_this IS BEGIN private_pkg.do_this; private_pkg.do_that; END; END; PACKAGE private_pkg ACCESSIBLE BY (public_pkg) IS PROCEDURE do_this; PROCEDURE do_that; END; 12c_accessible_by.sql Copyright 2013 Feuerstein and Associates Page 8

9 Grant Roles to Program Units You can now grant roles to program units, so you finetune 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 Copyright 2013 Feuerstein and Associates Page 9

10 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 Copyright 2013 Feuerstein and Associates Page 10

11 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 Copyright 2013 Feuerstein and Associates Page 11

12 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". Copyright 2013 Feuerstein and Associates Page 12

13 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 Copyright 2013 Feuerstein and Associates Page 13

14 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 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 Copyright 2013 Feuerstein and Associates Page 14

15 Oracle12c New PL/SQL Features Oracle PL/SQL Programming 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. Copyright 2013 Feuerstein and Associates Page 15