KScope19 - SQL Features

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SQLThe meanest, fastest thing out there
Connor McDonald
2

Connor McDonald

Copyright © 2018, Oracle and/or its affiliates. All rights reserved. |Copyright © 2018, Oracle and/or its affiliates. All rights reserved. |
4

5

Copyright © 2018, Oracle and/or its affiliates. All rights reserved. |
Stuff
youtube bit.ly/youtube-connor
blog bit.ly/blog-connor
twitter bit.ly/twitter-connor
400+ posts mainly on database & development
250 technical videos, new uploads every week
rants and raves on tech and the world :-)

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

https://asktom.oracle.com

26
"fine-grained to perform a single function"
"Each service is ... minimal, and complete"
https://en.wikipedia.org/wiki/Microservices
select COUNT(*)
from PEOPLE
where GENDER = 'MALE'

30
"By abstracting the underlying implementation"
"describes the expected behaviour ... but can have multiple implementations"
https://en.wikipedia.org/wiki/Application_programming_interface
select NAME, STREET_NO, ZIP_CODE
from PEOPLE p,
ADDRESS a
where p.AGE > 50
and p.ADDRESS_ID = a.ADDRESS_ID;

... yet we end up data processing :-(
34

this session is not about ...
37

SQL> with x( s, ind ) as
2 ( select sud, instr( sud, '.' )
3 from ( select replace(replace(
4 replace(replace(:board,'-'),'|'),' '),chr(10)) sud
5 from dual )
6 union all
7 select substr(s,1,ind-1)||z||substr(s,ind+1)
8 , instr(s,'.',ind+1)
9 from x
10 , ( select to_char( rownum ) z
11 from dual connect by rownum <= 9 ) z
12 where ind > 0
13 and not exists (
14 select null
15 from ( select rownum lp from dual
16 connect by rownum <= 9 )
17 where z = substr(s,trunc((ind-1)/9)*9+lp,1)
40

18 or z = substr(s,mod(ind-1,9)-8+lp*9,1)
19 or z = substr(s,mod(trunc((ind-1)/3),3)*3
20 +trunc((ind-1)/27)*27+lp
21 +trunc((lp-1)/3)*6,1)
22 )
23 ),
24 result as (
25 select s
26 from x
27 where ind = 0 )
28 select
29 regexp_replace(substr(s,(idx-1)*9+1,9),
30 '(...)(...)(...)',
31 '1|2|3')||
32 case when mod(idx,3)=0 then chr(10)||rpad('-',11,'-') end soln
33 from result,
34 ( select level idx
35 from dual
36 connect by level <= 9 )
41
Ack: Anton Scheffer,
https://technology.amis.nl

SQL> variable board varchar2(1000)
SQL> begin :board :=
2 '53.|.7.|...
3 6..|195|...
4 .98|...|.6.
5 -----------
6 8..|.61|..3
7 4..|8.3|..1
8 7..|.2.|..6
9 -----------
10 .6.|...|28.
11 ...|419|..5
12 ...|.8.|.79
13 ';
14 end;
42
5 3 7
6 1 9 5
9 8 6
8 6 1 3
4 8 3 1
7 2 6
6 2 8
4 1 9 5
8 7 9

SOLUTION
-----------
534|678|912
672|195|348
198|342|567
-----------
859|761|423
426|853|791
713|924|856
-----------
961|537|284
287|419|635
345|286|179
-----------
43
sud.sql

44
100%
% of developers that
will need to solve Sudoku
as part of their job

45
100%
% of developers that need
to get real stuff done

DBA friendship is important
53
oc00.sql

"Employee salary list,
plus department total,
plus grand total"
56

SQL> select empno, ename, sal, deptno from emp
2 order by deptno;
EMPNO ENAME SAL DEPTNO
---------- ---------- ---------- ----------
7782 CLARK 2450 10
7839 KING 5000 10
7934 MILLER 1300 10
...
7900 JAMES 950 30
7698 BLAKE 2850 30
7654 MARTIN 1250 30
58
SQL> select deptno,
2 sum(sal)
3 from emp
4 group by deptno
5 order by deptno;
DEPTNO SUM(SAL)
---------- ----------
10 8750
20 10875
30 9400
SQL> select sum(sal) from emp;
SUM(SAL)
----------
29025

SQL> select empno, ename, sal, deptno from emp
2 order by deptno;
EMPNO ENAME SAL DEPTNO
---------- ---------- ---------- ----------
7782 CLARK 2450 10
7839 KING 5000 10
7934 MILLER 1300 10
...
7900 JAMES 950 30
7698 BLAKE 2850 30
7654 MARTIN 1250 30
60
SQL> select deptno,
2 sum(sal)
3 from emp
4 group by rollup(deptno)
5 order by deptno;
DEPTNO SUM(SAL)
---------- ----------
10 8750
20 10875
30 9400
29025

EMPNO SAL DEPTNO
---------- ---------- ----------
7782 2450 10
7839 5000 10
7934 1300 10
7566 2975 20
7902 3000 20
7876 1100 20
7369 800 20
62
DEPTNO SUM(SAL)
---------- ----------
10 8750
20 10875
30 9400
29025
7782 2450 10
7839 5000 10
7934 1300 10
7566 2975 20
10 8750

SQL> select deptno,
2 nvl2(rownum,max(empno),null) empno,
3 nvl2(rownum,max(ename),null) ename,
4 sum(sal)
5 from emp
6 group by rollup(deptno,rownum)
7 order by deptno,empno;
DEPTNO EMPNO ENAME SUM(SAL)
---------- ---------- ---------- ----------
10 7782 CLARK 2450
10 7839 KING 5000
10 7934 MILLER 1300
10 8750
20 7369 SMITH 800
20 7566 JONES 2975
...
30 7900 JAMES 950
30 9400
2902564

SQL> select deptno,job,sum(sal) from scott.emp
2 group by CUBE(deptno,job)
3 order by deptno,job;
DEPTNO JOB SUM(SAL)
---------- --------- ----------
10 CLERK 1300
10 MANAGER 2450
10 PRESIDENT 5000
10 8750
20 ANALYST 6000
20 CLERK 1900
20 MANAGER 2975
20 10875
30 CLERK 950
30 MANAGER 2850
30 SALESMAN 5600
30 9400
ANALYST 6000
CLERK 4150
MANAGER 8275
PRESIDENT 5000
SALESMAN 5600
29025
66

SQL> select deptno, job, mgr, sum(sal) from emp
2 group by grouping sets (
3 (deptno),
4 (job,mgr), () ) ;
DEPTNO JOB MGR SUM(SAL)
---------- --------- ---------- ----------
CLERK 7902 800
PRESIDENT 5000
CLERK 7698 950
CLERK 7788 1100
CLERK 7782 1300
SALESMAN 7698 5600
MANAGER 7839 8275
ANALYST 7566 6000
10 8750
20 10875
30 9400
29025
68

C#, C++ ESB Tuxedo
Weblogic
Stored
Procedure
71

for (int i = 0; i < WinningCombinations.Count; ++i)
{
if (WinningCombinations[i].Investment > 0 &&
WinningCombinations[i].PrimaryDividend > MinDividendDeadHeat)
{
maxDivisor =
Math.Max(maxDivisor, WinningCombinations[i].Divisor);
}
}
for (int i = 0; i < WinningCombinations.Count; ++i)
{
if (WinningCombinations[i].Investment > 0 &&
WinningCombinations[i].PrimaryDividend > MinDividendDeadHeat)
{
WinningCombinations[i].Divisor =
maxDivisor / WinningCombinations[i].Divisor;
sumNewDivisors += WinningCombinations[i].Divisor;
}
}72

query blocks =
self documenting SQL
79

select emp.*
from emp,
( select trunc(hiredate,'YYYY'), max(empno) empno
from emp
where empno > 0
group by trunc(hiredate,'YYYY') ) x,
( select deptno, avg(sal)
from emp
group by deptno ) y
where x.empno = emp.empno
and y.deptno = emp.deptno
80

Id | Operation | Name |
----------------------------------------------|
0 | SELECT STATEMENT | |
1 | HASH JOIN | |
2 | TABLE ACCESS BY INDEX ROWID | EMP |
3 | NESTED LOOPS | |
4 | VIEW | |
5 | SORT GROUP BY | |
6 | TABLE ACCESS BY INDEX ROWID| EMP |
7 | INDEX FULL SCAN | E2 |
8 | INDEX RANGE SCAN | E1 |
9 | VIEW | |
81

?
82
select emp.*
from emp,
( select trunc(hiredate,'YYYY'), max(empno) empno
from emp
where empno > 0
( select deptno, avg(sal)
from emp
group by deptno ) y
Id | Operation | Name |
----------------------------------------------|
1 | HASH JOIN | |
4 | VIEW | |
9 | VIEW | |

select emp.*
from emp,
( select /*+ QB_NAME(YR_HIRE) */
trunc(hiredate,'YYYY'), max(empno) empno
from emp
where empno > 0
( select /*+ QB_NAME(AV_SAL) */
deptno, avg(sal)
from emp
group by deptno ) y
83
select emp.*
from emp,
( select /*+ QB_NAME(YR_HIRE) */
trunc(hiredate,'YYYY'), max(empno) empno
from emp
where empno > 0
( select /*+ QB_NAME(AV_SAL) */
deptno, avg(sal)
from emp
group by deptno ) y

Id | Operation | Name | Query Block
----------------------------------------------|--------------
1 | HASH JOIN | |
4 | VIEW | |
9 | VIEW | |
SEL$1
SEL$1
AV_SAL
AV_SAL
AV_SAL
AV_SAL
SEL$1
YR_HIRE
YR_HIRE
YR_HIRE
YR_HIRE
84

SQL> insert into MY_TABLE
2 select *
3 from MY_HUGE_GREAT_FAT_TABLE;
87
MY_HUGE_GREAT_FAT_TABLE;

2 select *
Elapsed: 06:12:34.00
93

2 select *
Elapsed: 06:12:34.00
ERROR at line 1:
ORA-01847: day of month must be between 1 and last day of month
94

SQL> select count(*) from MY_TABLE;
COUNT(*)
----------
0
98

2 select *
3 from MY_HUGE_GREAT_FAT_TABLE
4 where "not a duplicate"
5 and "datatypes are ok"
6 and "foreign keys are ok"
7 and "check constraints are ok"
103

SQL> exec DBMS_ERRLOG.CREATE_ERROR_LOG('EMP')
104

DBMS_ERRLOG.CREATE_ERROR_LOG (
dml_table_name IN VARCHAR2,
err_log_table_name IN VARCHAR2 := NULL,
err_log_table_owner IN VARCHAR2 := NULL,
...
106

SQL> desc ERR$_EMP
Name Null? Type
----------------------------- -------- ----------------
ORA_ERR_NUMBER$ NUMBER
ORA_ERR_MESG$ VARCHAR2(2000)
ORA_ERR_ROWID$ ROWID
ORA_ERR_OPTYP$ VARCHAR2(2)
ORA_ERR_TAG$ VARCHAR2(2000)
EMPNO VARCHAR2(4000)
ENAME VARCHAR2(4000)
JOB VARCHAR2(4000)
MGR VARCHAR2(4000)
HIREDATE VARCHAR2(4000)
SAL VARCHAR2(4000)
COMM VARCHAR2(4000)
DEPTNO VARCHAR2(4000)
107

SQL> select * from NEW_DATA;
EMPNO SAL DEPTNO
---------- ---------- ----------
1000 5000 20
100X 3550 10
2000 2500 50
7934 4000 20
111
non-numeric
no dept 50
duplicate

SQL> exec dbms_errlog.create_error_log( 'EMP' );
PL/SQL procedure successfully completed.
SQL> insert into EMP (empno,sal,deptno)
2 select empno,sal,deptno
3 from NEW_DATA
4 LOG ERRORS REJECT LIMIT UNLIMITED;
1 row created.
112
50

SQL> select ORA_ERR_OPTYP$ op, ORA_ERR_MESG$, EMPNO
2 from ERR$_EMP
OP ORA_ERR_MESG$ EMPNO
-- ------------------------------------------------------------ -----
I ORA-01722: invalid number 100X
I ORA-02291: integrity constraint (SCOTT.FK_DEPTNO) violated 2000
I ORA-00001: unique constraint (SCOTT.PK_EMP) violated 7934
113

116
SQL> select *
2 from timeslots;
HR
--
8
9
10
11
12
13
14
15
16
SQL> select *
2 from bookings;
HR ROOM WHO
------- ---------- -------
8 Room2 PETE
9 Room1 JOHN
11 Room1 MIKE
14 Room2 JILL
15 Room2 JANE
16 Room1 SAM

bookings by hour
117
conventional outer join

118
SQL> SELECT hrs.hr, t1.room, t1.who
2 from timeslots hrs
3 left outer join bookings t1
4 on hrs.hr = t1.hr
5 order by 1
HR ROOM WHO
------- ---------- ----------
8 Room2 PETE
9 Room1 JOHN
10
11 Room1 MIKE
12
13
14 Room2 JILL
15 Room2 JANE
16 Room1 SAM
118

120
HR ROOM WHO
------- ---------- ----------
8 Room2 PETE
9
10
11
12
13
14 Room2 JILL
15 Room2 JANE
16
HR ROOM WHO
------- ---------- ----------
8
9 Room1 JOHN
10
11 Room1 MIKE
12
13
14
15
16 Room1 SAM

121
SQL> select *
2 from timeslots;
HR
--
8
9
10
11
12
13
14
15
16
x "Room 1"
x "Room 2"
...
x "Room n"

SQL> SELECT hrs.hr, t1.room, t1.who
2 FROM bookings t1
3 PARTITION BY (t1.room)
4 RIGHT OUTER JOIN timeslots ON (hrs.hr = t1.hr)
5 order by 1,2
HR ROOM WHO
--------- ---------- ----------
8 Room1
9 Room1 JOHN
10 Room1
11 Room1 MIKE
12 Room1
13 Room1
14 Room1
15 Room1
16 Room1 SAM
8 Room2 PETE
9 Room2
10 Room2
11 Room2
12 Room2
13 Room2
14 Room2 JILL
15 Room2 JANE
16 Room2 123

SQL> WITH last_hire AS
2 ( select deptno, max(hiredate)
3 from emp
4 group by deptno
5 )
6 select * from last_hire;
DEPTNO MAX(HIRED
---------- ---------
30 03-DEC-81
20 12-JAN-83
10 23-JAN-82
128

"who cares?....... more code, same result"
129

WITH last_hire AS
(
select deptno, max(hiredate)
from emp
group by deptno
)
select * from last_hire;
130

relational is a rigorous model ...
133

relational is the dominant model ...
134

relational ... can sortta suck
135

"data is represented as mathematical n-ary
relations, an n-ary relation being a subset of the
Cartesian product of n domains."
138

"First, get the total salary paid by each department,
then get the average of these totals,
then list those departments above that average"
142
SQL ?

"First, get the total salary paid by department...
SQL> WITH dept_salaries AS (
2 SELECT dname, SUM(sal) dept_sal
3 FROM emp e, dept d
4 WHERE e.deptno = d.deptno
5 GROUP BY dname),
143

"...then get the average of these totals...
6 avg_sal AS ( SELECT AVG(dept_sal) avsal
7 FROM dept_salaries)
144

"...then list those departments above average."
8 SELECT * FROM dept_salaries d, avg_sal a
9 WHERE d.dept_sal > a.avsal
10 ORDER BY d.dname;
145

SQL> WITH dept_salaries AS (
2 SELECT dname, SUM(sal) dept_sal
3 FROM emp e, dept d
4 WHERE e.deptno = d.deptno
5 GROUP BY dname),
6 avg_sal AS ( SELECT AVG(dept_sal) avsal
7 FROM dept_salaries)
8 SELECT * FROM dept_salaries d, avg_sal a
9 WHERE d.dept_sal > a.avsal
10 ORDER BY d.dname;
146

recall: partitioned outer join
151

152
SQL> with raw_data as (
2 select
3 hrs.hr,
4 t1.room,
5 t1.who
6 from bookings t1
7 partition by (t1.room)
8 right outer join hrs
9 on (hrs.hr = t1.hr)
10 order by
11 hr, room
12 )
13 select
14 json_arrayagg(
15 json_object(key room||to_char(hr) value who )
16 order by hr ) as meetings
17 from raw_data ;
[{"Room1-08":null},
{"Room1-09":"JOHN"},
{"Room1-10":null},
{"Room1-11":"MIKE"},
{"Room1-12":null},
...
...
{"Room2-14":"JILL"},
{"Room2-15":null},
{"Room2-16":"JANE"}]

155
"employees by hiredate, recent first"

SQL> select empno, ename, hiredate
2 from emp
3 where rownum <= 5
4 order by hiredate desc;
EMPNO ENAME HIREDATE
---------- ---------- -------------------
7654 MARTIN 28/09/1981 00:00:00
7566 JONES 02/04/1981 00:00:00
7521 WARD 22/02/1981 00:00:00
7499 ALLEN 20/02/1981 00:00:00
7369 SMITH 17/12/1980 00:00:00
156

SQL> select *
2 from (
3 select empno, ename, hiredate
4 from emp
5 order by hiredate desc
6 )
7 where rownum <= 5;
---------- ---------- ---------
7876 ADAMS 12-JAN-83
7788 SCOTT 09-DEC-82
7934 MILLER 23-JAN-82
7900 JAMES 03-DEC-81
7902 FORD 03-DEC-81
158

SQL> select *
2 from (
3 select
4 empno, ename, hiredate,
5 row_number() over ( order by hiredate desc) rn
6 from emp
7 )
8 where rn <= 5;
159

2 from emp
4 fetch first 5 rows only;
---------- ---------- ---------
7876 ADAMS 12-JAN-83
7788 SCOTT 09-DEC-82
7934 MILLER 23-JAN-82
7900 JAMES 03-DEC-81
7902 FORD 03-DEC-81
160

161
"TL;DR ... my app can do it"

public static void Paging(Connection conn ) throws Exception
{
PreparedStatement sql_stmt =
conn.prepareStatement(
"select empno, ename, hiredate
from emp
order by hiredate desc");
ResultSet rset = sql_stmt.executeQuery();
int i = 0;
while( rset.next() )
{
...
i = i + 1;
if (i > 5) {
break;
}
}
rset.close();
}
162

SQL> select *
2 from (
3 select empno, ename, hiredate
4 from emp
6 )
7 where rownum <= 5;
166
------------------------------------------------
| Id | Operation | Name | Rows |
------------------------------------------------
| 0 | SELECT STATEMENT | | 5 |
|* 1 | COUNT STOPKEY | | |
| 2 | VIEW | | 14 |
|* 3 | SORT ORDER BY STOPKEY| | 14 |
| 4 | TABLE ACCESS FULL | EMP | 14 |
------------------------------------------------

2 from emp
4 fetch first 5 rows only;
167
-------------------------------------------------
-------------------------------------------------
|* 1 | VIEW | | 14 |
|* 2 | WINDOW SORT PUSHED RANK| | 14 |
| 3 | TABLE ACCESS FULL | EMP | 14 |
-------------------------------------------------

you get other benefits
168
oc02.sql

169
"but what about the next page ?"

2 from emp
4 offset 5 rows fetch first 5 rows only;
---------- ---------- ---------
7839 KING 17-NOV-81
7654 MARTIN 28-SEP-81
7844 TURNER 08-SEP-81
7782 CLARK 09-JUN-81
7698 BLAKE 01-MAY-81
172

2 from emp
HIREDATE EMPNO ENAME
--------- ---------- --------
12-JAN-83 7876 ADAMS
09-DEC-82 7788 SCOTT
23-JAN-82 7934 MILLER
03-DEC-81 7902 FORD
03-DEC-81 7900 JAMES
17-NOV-81 7839 KING
28-SEP-81 7654 MARTIN
08-SEP-81 7844 TURNER
09-JUN-81 7782 CLARK
01-MAY-81 7698 BLAKE
02-APR-81 7566 JONES
22-FEB-81 7521 WARD
20-FEB-81 7499 ALLEN
17-DEC-80 7369 SMITH
174
fetch first 5 rows
offset 5 fetch next ...
17-FEB-91 7521 BROWN

2 from emp
HIREDATE EMPNO ENAME
--------- ---------- --------
12-JAN-83 7876 ADAMS
09-DEC-82 7788 SCOTT
23-JAN-82 7934 MILLER
03-DEC-81 7902 FORD
03-DEC-81 7900 JAMES
17-NOV-81 7839 KING
28-SEP-81 7654 MARTIN
08-SEP-81 7844 TURNER
09-JUN-81 7782 CLARK
01-MAY-81 7698 BLAKE
02-APR-81 7566 JONES
22-FEB-81 7521 WARD
20-FEB-81 7499 ALLEN
17-DEC-80 7369 SMITH
175
17-FEB-91 7521 BROWN
2 from emp
3 where hiredate < :last_shown

176
"an expensive query per page ?!?!

SQL> with first_200 as
2 ( select f.*, rownum r
3 from
4 ( select *
5 from t
6 order by owner, object_name desc
7 ) f
8 where rownum <= 200
9 )
10 select *
11 from first_200
12 where r <= 10
178
/*+ result_cache */ rownum r, f.*
oc03.sql
r between 11 and 20

we all know about analytics
180

SQL> select row_number() OVER ( order by sal )
2 from emp
3 ...
181
https://bit.ly/analytic_sql

182
“Show me lowest salary for each department...”
SQL> select deptno, min(sal)
2 from emp
3 group by deptno;
“...and I need to know who has that
lowest salary as well”
SQL> select deptno, empno, min(sal)
2 from emp
3 group by deptno;
ORA-00979: not a GROUP BY expression

SQL> select deptno, min(sal), min(empno)
2 KEEP ( dense_rank FIRST order by sal) empno
3 from emp
4 group by deptno
5 /
DEPTNO MIN(SAL) EMPNO
---------- ---------- ----------
10 1300 7934
20 800 7369
30 950 7900
Emp 7934 has the
lowest salary in dept 10
184

"Find 10 consecutive deposits in a
24 hour period, then
a withdrawal within three days of
the last deposit, at a different retail outlet"
191

ACCT TSTAMP TYP AMT LOC
---------- ------------------ ---------- ------- ----
54261 25/01/19 17:20:55 Deposit 100 Perth
54261 25/01/19 17:56:58 Deposit 165 Perth
54261 26/01/19 11:24:14 Deposit 30 Subiaco
54261 26/01/19 11:47:53 Deposit 45 Guildford
54261 26/01/19 12:59:38 Deposit 100 Claremont
54261 26/01/19 13:26:04 Deposit 80 Perth
54261 26/01/19 14:41:09 Deposit 50 Perth
54261 26/01/19 14:53:12 Deposit 50 Nedlands
54261 26/01/19 15:15:05 Deposit 50 Leederville
54261 26/01/19 15:51:17 Deposit 50 Guildford
54261 26/01/19 16:15:02 Deposit 120 Perth
54261 26/01/19 16:36:51 Deposit 100 Perth
54261 26/01/19 16:55:09 Deposit 100 Perth
54261 26/01/19 18:07:17 Withdrawal -500 Nedlands
192

SQL> select acct, tstamp, wthd_tstamp, txn_type, amt
2 from account_txns
3 MATCH_RECOGNIZE
4 ( partition by acct
5 order by tstamp
6 measures
7 dep.tstamp dep_tstamp,
8 wthd.tstamp wthd_tstamp
9 all rows per match
10 pattern ( dep{10,} wthd )
11 define
12 dep as
13 txn_type = 'Deposit',
14 wthd as
15 txn_type = 'Withdrawal'
16 and last(dep.tstamp)-first(dep.tstamp) < interval '1' day
17 and wthd.tstamp - last(dep.tstamp) < interval '3' day
18 and wthd.location != last(dep.location)
19 ) 195

196
https://tinyurl.com/pattern-match

199
"talking" to your database
... makes it faster

select prod_id, max(amount)
from stores st,
customers c,
sales s
where s.cust_id = c.cust_id(+)
and c.store_id = st.store_id
and s.amount > 10
group by prod_id
202
hash outer join ? nested loop ?
STORES first ?
sort merge ?

---------------------------------------------------
---------------------------------------------------
| 1 | HASH GROUP BY | | 100 |
|* 2 | HASH JOIN | | 990K |
| 3 | NESTED LOOPS SEMI | | 5000 |
| 4 | TABLE ACCESS FULL| CUSTOMERS | 5000 |
|* 5 | INDEX UNIQUE SCAN| STORE_IX | 50 |
|* 6 | TABLE ACCESS FULL | SALES | 990K |
---------------------------------------------------
203

204
can we do better ?
add indexes ?
rewrite query ?
result cache ?
materialized view ?

205
share your knowledge with the db
oc04.sql

KScope19 - SQL Features

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