Reconciling APEX and the Thick Database Paradigm

Transcription

1 Reconciling APEX and the Thick Database Product Manager for PL/SQL and EBR at Oracle HQ Not known for my brevity. Having trouble squeezing my own views not necessarily my employer's into 140 chars. Or, for that matter, 60 minutes. Spring 2017

2 Introductory remarks

3 Discussion with Niels de Bruijn & Joel Kallman at DOAG Toon Koppelaars Steven Feuerstein, Dan McGann, et al Cary Millsap Marc Sewtz & Dan McGann (yesterday) etc., etc... The commit in PL/SQL is bad twitter storm October 2016 The Gerald Venzl, Tim Hall, et al old farts brigade accusation

4 Setting the scope

5 Developers write software for a huge variety of purposes We need to set the scope for our discussion The best way is to think of a modern app like Moovit

6 Agenda

7 1 2 The case for implementing all business logic inside the database - Modular design principles applied to applications backed by Oracle Database - What is SQL, and how do you make it happen? - The hard shell paradigm - PL/SQL s unique specific features for making SQL happen Myth busting - Data rules can be enforced by code outside of the database - You can save database CPU and improve scalability by implementing business logic outside the database - You can rely on robotically generated SQL - You can change code in the database without application downtime - There s no tooling for PL/SQL - You can t provide each developer with a private sandbox for PL/SQL development

8 Setting the scene

9 Large software systems must be built from modules. A module hides its implementation behind an interface that exposes its functionality. This is computer science s most famous principle.

10 Large software systems must be built from modules. A module hides its implementation behind an interface that exposes its functionality. This is computer science s most famous principle. For applications that use an Oracle Database, the database is the persistence module. The tables and the SQL statements that manipulate them are the implementation details. The interface is expressed with PL/SQL.

11 Large software systems must be built from modules. A module hides its implementation behind an interface that exposes its functionality. This is computer science s most famous principle. For applications that use an Oracle Database, the database is the persistence module. The tables and the SQL statements that manipulate them are the implementation details. The interface is expressed with PL/SQL. Developers and end-users of applications built this way are happy with their correctness, maintainability, security, and performance.

12 Large software systems must be built from modules. A module hides its implementation behind an interface that exposes its functionality. This is computer science s most famous principle. For applications that use an Oracle Database, the database is the persistence module. The tables and the SQL statements that manipulate them are the implementation details. The interface is expressed with PL/SQL. Developers and end-users of applications built this way are happy with their correctness, maintainability, security, and performance. But when developers follow the NoPlsql paradigm, their applications have problems in each of these areas and end-users suffer.

13 And yet Number of Programming Jobs Ranked by Language (Dice.com data) Summer

14 Modular design principles applied to applications backed by Oracle Database

15 what are the modules?

16 business functions matter

17 table designs can change

18 responsibility needs authority

19 encase the database in a hard shell

20 the framework alternative

21

22 NoAnything

23 What is SQL? How do you make it happen?

24 a SQL statement describes its intended effect

25 you need an if-then-else language to make SQL happen

26 how good is it at doing SQL?

27 where does it run?

28 The hard shell paradigm

29 commit select insert update delete

30 commit select insert update delete

31 s1 sn s2 commit s7 select update insert delete s3 s6 s4 s5

32 s1 sn s2 commit s7 select update insert delete s3 ORDS s6 s4 s5

33 -- primitive anonymous block statement begin Pkg.Bulk_Insert(:Rows); end;

34 PL/SQL s unique specific features for making SQL happen

35 procedure p(lo in t.c3%type, Hi in t.c3%type) is begin for r in ( select t.c1, t.c2 from t where t.c3 between p.lo and p.hi order by 1) loop Buffer_Row_For_Display(r.c1, r.c2); end loop; end p;

36 procedure p(lo in t.c3%type, Hi in t.c3%type) is begin for r in ( select t.c1, t.c2 from t where t.c3 between p.lo and p.hi order by 1) loop Buffer_Row_For_Display(r.c1, r.c2); end loop; end p;

37 procedure p(lo in t.c3%type, Hi in t.c3%type) is begin for r in ( select t.c1, t.c2 from t where t.c3 between p.lo and p.hi order by 1) loop Buffer_Row_For_Display(r.c1, r.c2); end loop; end p;

38 procedure p(lo in t.c3%type, Hi in t.c3%type) is begin for r in ( select t.c1, t.c2 from t where t.c3 between p.lo and p.hi order by 1) loop Buffer_Row_For_Display(r.c1, r.c2); end loop; end p;

39 SELECT T.C1, T.C2 FROM T WHERE T.C3 BETWEEN :B2 AND :B1 ORDER BY 1

40 procedure p(lo in t.c3%type, Hi in t.c3%type) is begin -- cursor implicitly opened select t.c1, t.c2 for r in ( from t where t.c3 between p.lo and p.hi order by 1) loop Buffer_Row_For_Display(r.c1, r.c2); end loop; end p; -- cursor implicitly closed

41 procedure p(lo in t.c3%type, Hi in t.c3%type) is begin for r in ( select t.c1, t.c2 from t where t.c3 between p.lo and p.hi order by 1) loop Buffer_Row_For_Display(r.c1, r.c2); end loop; end p; bulkification

42 native dynamic SQL expressive rarely needed

43 no make: the promise brought by static dependency tracking

44 every single artifact that implements the business functions is in one managed universe: the Oracle Database

45 metadata for everything static definitions run-time behavior homogeneously available via SQL and PL/SQL for mechanical analysis

46 metadata for everything static definitions run-time behavior homogeneously available via SQL and PL/SQL for mechanical analysis DBA_Objects, DBA_Source, DBA_Procedures, DBA_Arguments, DBA_Identifiers, DBA_Dependencies, DBA_Tables, DBA_Indexes, DBA_Constraints, DBA_Views, DBA_Sequences, DBA_Triggers,...

47 metadata for everything static definitions run-time behavior homogeneously available via SQL and PL/SQL for mechanical analysis v$sql, DBMS_Xplan, DBMS_Hprof,...

48 everything you d ordinarily expect as a programmer SQL Developer, GUI debugging compiler warnings (bad SQL aware) conditional compilation tests package globlals and so on...

49 Deploying PL/SQL code changes with zero downtime: EBR is the key

50 Oracle E-Business Release 12.2 does it

51 Salesforce.com does it

52 American Express does it

53 and so can you!

54 Empowering each developer to provision their own databases

55 PDBs as sandboxes snapshot clone

56 provisioning app with PL/SQL API from SQL*Plus or APEX

57 trash a test database and then re-instate it in its pristine starting state in minutes

58 difference in kind becomes difference in degree

59 Oracle Database Development Engineer job role now well-defined

60 can: schema design, SQL (incl. execution plans), PL/SQL

61 need not know: RMAN, Data Guard, RAC deployment, etc

62 Conclusion

63 an application whose data isn t persisted and retrieved correctly is worthless it s the data, stupid!

64 an application whose data isn t persisted and retrieved correctly is worthless it s the data, stupid! protect your data inside a hard PL/SQL shell select, insert, update, delete come only from PL/SQL it s the time-honored way

65 an application whose data isn t persisted and retrieved correctly is worthless it s the data, stupid! protect your data inside a hard PL/SQL shell select, insert, update, delete come only from PL/SQL it s the time-honored way performance and security matter too the thick database paradigm ensures these

66 And now, stepping out of rôle, let s look at some real code really running

67 Internet-facing self-service app to manage your bank account Tables: Account_Kinds Account_Holders Accounts Transactions...and so on... Business function: Transfer funds internally insert a row into Account_Kinds Honor the rules: can t go into the red can t xfer more than threshold amount in a calendar month...and so on..

68 Switch to demo

69