Sangam 19 - PLSQL still the coolest

1
Connor McDonald
bit.ly/techguysong

PL/SQL - still super cool
Connor McDonald
Database Advocate
Copyright © 2019 Oracle and/or its affiliates.

6
Me
youtube bit.ly/youtube-connor
blog connor-mcdonald.com
twitter @connor_mc_d
400+ posts mainly on database & development
250 technical videos, new uploads every week
rants and raves on tech and the world :-)

7
etc...
facebook bit.ly/facebook-connor
linkedin bit.ly/linkedin-connor
instagram bit.ly/instagram-connor
slideshare bit.ly/slideshare-connor

9https://asktom.oracle.com/officeho

Sangam 19 - PLSQL still the coolest

17
meets performance objectives
(really a business objective)

18
meets development objectives

19
meets security objectives

23
PL/SQL should help achieve this for you

25
let's look at real life ...

26
"We'd never do that .... that's stupid"

37
remember definition of success

38
performance, maintenance, security

43
https://dzone.com/articles/the-smartdb-resource-center

44
utopia, n:
"an imagined a place or state of things in which everything is perfect."

45
100%
% people using
any form of SmartDB

47
100%
% closeness to full SmartDB

49
forget philosophy...focus on success

50
can even small PL/SQL investment help ?

54
my app = primary key lookup

56
SQL> create or replace
2 function simplepk(i int) return int is
3 res int;
4 begin
5 select pk
6 into res
7 from parse_demo
8 where pk = i;
9 return res;
10 end;
SimplePK

59
"More layers...more expensive"

63
2 procedure simpleapi(i1 int, i2 int, o1 out int, o2 out int, o3 out int) is
3 begin
4 select region_id into o1 from customer where id = i1;
5
6 for i in ( select order_id from cust_orders where cust_id = i2 )
7 loop
8 o2 := i.order_id;
9 end loop;
10
11 select count(*) into o3 from order_items where order_id = o2;
12 end;
SimpleAPI

66
the best java (et al) can do

68
we'll come back to why shortly...

71
"Crash Early"
"A dead program normally does a lot less damage than a crippled one."

72
C:src> type MyApp.java
...
...
PreparedStatement s =
con.prepareStatement("select any piece of old crap from dual");
...
...
C:src> javac SimplePKcache.java
[no errors]

73
2 procedure MY_PROC is
3 begin
...
...
24 select any piece of old crap from dual;
...
...
75 end;
76 /
Warning: Procedure created with compilation errors.

75
the lazy way is the optimal way

76
rs = stmt.executeQuery(
"select ename from emp where empno = " + v_empno );
while(rs.next()) {
v_ename = rs.getInt(1);
}
PreparedStatement pstmt =
con.prepareStatement("select ename from emp where empno = ?");
pstmt.setInt(1, v_empno);
rs = pstmt.executeQuery();
while(rs.next()) {
}

77
building SQL by concatenation

79
select ename
from emp
where empno = 6543
select ename
from emp
where empno = 6543
and 1=0
union all
select table_name
from all_tables
where table_name like '%SECURITY%'
select ename
from emp
where empno = 6543
and 1=0
union all
select username
from app_security
where ...
rs = stmt.executeQuery(
"select ename from emp where empno = " + v_empno );

80
begin
select ename
into v_ename
from emp
where empno = v_empno;
begin
dbms_sql.parse(
v_cur,
'select ename from emp where empno = '||v_empno,
dbms_sql.native );
dbms_sql.define_column(v_cur, 1, v_ename, 30);
l_status := dbms_sql.execute(v_cur);
while ( dbms_sql.fetch_rows(v_cur) > 0 ) loop
dbms_sql.column_value(v_cur, 1, v_ename);
end loop;

81
begin
execute immediate
'select ename from emp where empno = '||v_empno
into v_ename;

82
"We're safe... we use an ORM"

https://snyk.io/blog/sequelize-orm-npm-library-found-vulnerable-to-sql-injection-attacks/

84
not just static versus dynamic

86
procedure GET_EMPS_FOR_JOB(p_job varchar2) is
begin
for i in (
select ename
from emp
where job = p_job
)
loop
...
end loop;
SQL> select ename from emp where job = 'SALES'

87
SELECT ENAME
FROM EMP
WHERE JOB = :B1
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 1 0.00 0.00 0 0 0 0
Execute 10000 0.17 0.14 0 0 0 0
Fetch 10000 0.07 0.09 24 20000 0 40000
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 20001 0.25 0.24 24 20000 0 40000

88
SELECT ENAME
FROM EMP
WHERE JOB = :B1
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 1 0.00 0.00 0 0 0 0
Execute 10000 0.17 0.14 0 0 0 0
Fetch 10000 0.07 0.09 24 20000 0 40000
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 20001 0.25 0.24 24 20000 0 40000

89
pstmt.setString(1,v_job);
while(rs.next()) {
}
pstmt.close();

90
select ename
from emp
where job = :1
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 10000 0.06 0.10 0 0 0 0
Execute 10000 0.14 0.15 0 0 0 0
Fetch 40000 0.12 0.10 24 40000 0 40000
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 50000 0.32 0.37 24 40000 0 40000

91
select ename
from emp
where job = :1
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 10000 0.06 0.10 0 0 0 0
Execute 10000 0.14 0.15 0 0 0 0
Fetch 40000 0.12 0.10 24 40000 0 40000
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 50000 0.32 0.37 24 40000 0 40000

92
OracleDataSource ods = new OracleDataSource();
ods.setImplicitCachingEnabled( true );
Properties cacheProps = new Properties();
cacheProps.put( "MaxStatementsLimit", "50" );
ods.setConnectionCacheProperties( cacheProps );
pstmt.setFetchSize(100);
pstmt.setString(1,v_job);
while(rs.next()) {
}
pstmt.close();

108
no application is 100% complete

109
data loading, data patching

123
SQL> desc DBA_DEPENDENCIES
Name Null? Type
----------------------------- -------- --------------------
OWNER NOT NULL VARCHAR2(128)
NAME NOT NULL VARCHAR2(128)
TYPE VARCHAR2(19)
REFERENCED_OWNER VARCHAR2(128)
REFERENCED_NAME VARCHAR2(128)
REFERENCED_TYPE VARCHAR2(19)
REFERENCED_LINK_NAME VARCHAR2(128)
DEPENDENCY_TYPE VARCHAR2(4)

124
2 procedure MY_PROC is
3 v_ename scott.emp.ename%type;
4 begin
5 select ename
6 into v_ename
7 from scott.emp
8 where 1=0;
9 end;
10 /
SQL> select name, referenced_name
2 from dba_dependencies
3 where name = 'MY_PROC';
NAME REFERENCED_NAME
-------------------- -------------------------------------
MY_PROC STANDARD
MY_PROC EMP

125
a common maintenance criticism

126
"Deployment means down time"

128
break the invalidation chain

proc A proc B proc C proc D
pack A pack B pack C pack D
body A body B body C body D

pack A pack B pack C pack D
body A body B body C
body D

133
edition based redefinition

134
procedure MY_PROC is
begin
...
... "v1 code"
...
end;
procedure MY_PROC is
begin
...
... "v2 code"
...
end;

137
the opportunity of better security

138
SQL> select username, program from v$session;
USERNAME PROGRAM
-------------------- ----------------------------
MY_SCHEMA JDBC Thin Client
...
...

140
there isn't a limit on schemas

141
least privilege is the best privilege

142
nothing connects to the data owner ... ever

143
ins,upd,del,sel privs
APP_CONNECTING
TABLES
MY_SCHEMA

144
execute privs
APP_CONNECTING
TABLES
MY_SCHEMA
PL/SQL

145
select privs
execute privs
APP_CONNECTING
TABLES
MY_SCHEMA
PL/SQL

147
execute privs
APP_CONNECTING
TABLES
MY_SCHEMA
PL/SQL

150
putting theory into practice

153
development team
C++
C#
no Oracle experience
no database experience !

155
C#, C++ ESB Tuxedo
Weblogic

156
public static void RaceStarted(int race_id)
{
...
}
public static void HorseScratched(int race_id, int horse_id)
{
...
}
public static void NewCustomer(int cust_seq, ...)
{
...
}
public static void DepositIntoAccount(int ...)
{
...
}

158
PROCEDURE customer_bet(
p_transaction_ts IN timestamp
,p_bet_type IN bet.bet_type%TYPE
,p_store IN bet.store%TYPE
,p_accountnum IN bet.bet_account_num%TYPE
,p_amount IN bet.amount%TYPE
...
);
PROCEDURE pay_winner(
p_transaction_ts IN timestamp
,p_bet_seq IN bet.bet_seq%TYPE
,p_bet_type IN bet.bet_type%TYPE
,p_store IN bet.store%TYPE
,p_accountnum IN bet.bet_account_num%TYPE
,p_amount_to_pay IN bet.paid_payout%TYPE
,p_amount_to_refund IN bet.paid_refunds%TYPE
...
);

160
the benefits can be addictive

162
"We added one procedure to solve one problem,
then another procedure to solve another problem,
and very quickly...now they want PLSQL everywhere"
- Office Hours, June 2019

163
addressing some common criticisms

164
"PL/SQL is not object oriented"

168
"We don't have PL/SQL skills"

170
if-then-else, loop, subroutines, parameters

172
"We struggle with good PL/SQL"

176
it doesn't have to be a war

177
it doesn't have to be utopia

178
PL/SQL is easy to learn, easy to write

179
good wins for small effort

180
kick starts the journey to big wins

183
Thank you
youtube bit.ly/youtube-connor
blog connor-mcdonald.com
twitter @connor_mc_d

Sangam 19 - PLSQL still the coolest

More Related Content

What's hot (20)

Similar to Sangam 19 - PLSQL still the coolest (20)

More from Connor McDonald (13)

Recently uploaded (20)

Sangam 19 - PLSQL still the coolest