rwp training sql hands-on exercise - oracle...rwp training sql hands-on exercise table_name...

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RWP Training SQL Hands-On Exercise

1. Run 01.query_1.sql

View the SQL Monitor Report.

Note any problems with the SQL execution.



SQL> SELECT /*+ monitor */

2 SUM(lo_quantity) lo_quantity,

3 SUM(lo_revenue) lo_revenue,

4 SUM(lo_supplycost) lo_supplycost

5 FROM lineorder

6 WHERE lo_promotion_id=192000

7 AND lo_orderpriority = '1-URGENT'

8 AND lo_shipmode = 'MAIL'

9 /

LO_QUANTITY LO_REVENUE LO_SUPPLYCOST

---------------- ------------------ ----------------

16044.00 2310218805.00 57579017.00

Elapsed: 00:00:02.49


RWP Training SQL Hands-On Exercise 2 seconds

Full Table Scan



2. Run 02.desc_lineorder.sql

Note any issues between the table columns and how the SQL statement is written.



SQL> desc lineorder

Name Null? Type

--------------------------------- -------- ----------

LO_ORDERKEY NUMBER

LO_LINENUMBER NUMBER

LO_CUSTKEY NUMBER

LO_PARTKEY NUMBER

LO_SUPPKEY NUMBER

LO_ORDERDATE DATE

LO_ORDERPRIORITY VARCHAR2(15)

LO_SHIPPRIORITY VARCHAR2(1)

LO_QUANTITY NUMBER

LO_EXTENDEDPRICE NUMBER

LO_ORDTOTALPRICE NUMBER

LO_DISCOUNT NUMBER

LO_REVENUE NUMBER

LO_SUPPLYCOST NUMBER

LO_TAX NUMBER

LO_COMMITDATE DATE

LO_SHIPMODE VARCHAR2(10)

LO_PROMOTION_ID VARCHAR2(6)

LO_PROMOTION_ID is a VARCHAR2





Why is the SQL statement executing faster now?



SQL> @03.query_1.sql

SQL>





5 FROM lineorder

6 WHERE lo_promotion_id='192000'



9 /


---------------- ------------------ ----------------

16044.00 2310218805.00 57579017.00

Elapsed: 00:00:00.76



1 second

Index Scan





Note any problems with the SQL execution.




SQL>





5 FROM lineorder




9 /


---------------- ------------------ ----------------

833238.00 118720566967.00 2945197263.00

Elapsed: 00:01:41.47



101 seconds

Index Scan Poor Cardinality Estimate



5. Run 05.check_lineorder_stats.sql

Note any issues with the table stats relative to the two queries.



TABLE_NAME COLUMN_NAME HISTOGRAM

------------------------------ ------------------------------ ---------------

LINEORDER LO_COMMITDATE NONE

LINEORDER LO_CUSTKEY NONE

LINEORDER LO_DISCOUNT NONE

LINEORDER LO_EXTENDEDPRICE NONE

LINEORDER LO_LINENUMBER NONE

LINEORDER LO_ORDERDATE NONE

LINEORDER LO_ORDERKEY NONE

LINEORDER LO_ORDERPRIORITY NONE

LINEORDER LO_ORDTOTALPRICE NONE

LINEORDER LO_PARTKEY NONE

LINEORDER LO_PROMOTION_ID NONE

LINEORDER LO_QUANTITY NONE

LINEORDER LO_REVENUE NONE

LINEORDER LO_SHIPMODE NONE

LINEORDER LO_SHIPPRIORITY NONE

LINEORDER LO_SUPPKEY NONE

LINEORDER LO_SUPPLYCOST NONE

LINEORDER LO_TAX NONE

No Histograms



6. Run 06.gather_stats_lineorder.sql

Regather stats on the lineorder table.



SQL> @06.gather_stats_lineorder.sql

SQL>

SQL> exec dbms_stats.gather_table_stats(user, 'LINEORDER', degree=>4);

PL/SQL procedure successfully completed.

Elapsed: 00:01:29.43



7. Run 07.check_lineorder_stats.sql

What changed with the stats on the lineorder table?



TABLE_NAME COLUMN_NAME HISTOGRAM

------------------------------ ------------------------------ ---------------

LINEORDER LO_COMMITDATE NONE

LINEORDER LO_CUSTKEY NONE

LINEORDER LO_DISCOUNT NONE

LINEORDER LO_EXTENDEDPRICE NONE

LINEORDER LO_LINENUMBER NONE

LINEORDER LO_ORDERDATE NONE

LINEORDER LO_ORDERKEY NONE

LINEORDER LO_ORDERPRIORITY FREQUENCY

LINEORDER LO_ORDTOTALPRICE NONE

LINEORDER LO_PARTKEY NONE

LINEORDER LO_PROMOTION_ID HYBRID

LINEORDER LO_QUANTITY NONE

LINEORDER LO_REVENUE NONE

LINEORDER LO_SHIPMODE FREQUENCY

LINEORDER LO_SHIPPRIORITY NONE

LINEORDER LO_SUPPKEY NONE

LINEORDER LO_SUPPLYCOST NONE

LINEORDER LO_TAX NONE

Histogram on LO_PROMOTION_ID




Has the execution plan or time for query 1 changed?




SQL>





5 FROM lineorder




9 /


---------------- ------------------ ----------------

16044.00 2310218805.00 57579017.00

Elapsed: 00:00:01.06



1 second

Index Scan




Has the execution plan or time for query 2 changed?




SQL>





5 FROM lineorder




9 /


---------------- ------------------ ----------------

833238.00 118720566967.00 2945197263.00

Elapsed: 00:00:02.11



2 seconds

Full Table Scan Better Cardinality Estimate





Note any problems with the SQL execution of query 3.




SQL>





5 FROM lineorder

6 JOIN supplier ON lo_suppkey = s_suppkey

7 WHERE s_nation in ('UNITED KINGDOM')

8 /


---------------- ------------------ ----------------

54160034.00 7714635359678.00 191116713490.00

Elapsed: 00:01:13.58



73 seconds

Poor Cardinality Estimates





Note any problems with the SQL execution of query 4.




2 d_month, d_year, s_nation,




6 FROM lineorder

7 JOIN date_dim ON lo_orderdate = d_datekey

8 JOIN part ON lo_partkey = p_partkey


10 WHERE d_year = 1994

11 AND s_region in ('ASIA')

12 AND s_nation in ('CHINA')

13 AND s_city in ('CHINA 1',

14 'CHINA 2',

15 'CHINA 3',

16 'CHINA 4',

17 'CHINA 5',

18 'CHINA 6',

19 'CHINA 7',

20 'CHINA 8',

21 'CHINA 9')

22 AND p_mfgr in ('MFGR#1','MFGR#3')

23 GROUP BY d_month, d_year, s_nation

24 ORDER BY d_month, d_year, s_nation

25 /

Elapsed: 00:01:34.13


RWP Training SQL Hands-On Exercise94 seconds

Index ScanPoor Cardinality Estimates



12. Run 12.set_parallel.sql

Set the degree of parallel on the tables and indexes.



alter table CUSTOMER parallel 4;

alter table DATE_DIM parallel 4;

alter table LINEORDER parallel 4;

alter table PART parallel 4;

alter table PROMOTION parallel 4;

alter table SUPPLIER parallel 4;

alter index LO_ORDERDATE parallel 4;

alter index LO_SUPPLIER parallel 4;

alter index LO_CUSTOMER parallel 4;

alter index LO_PART parallel 4;

alter index LO_PROMOTION parallel 4;

alter index SUPPLIER_PK parallel 4;

alter index PART_PK parallel 4;

alter index DATE_DIM_PK parallel 4;

alter index CUSTOMER_PK parallel 4;





Note any changes in the execution plan or run time with parallel execution.




SQL>





5 FROM lineorder



8 /


---------------- ------------------ ----------------

54160034.00 7714635359678.00 191116713490.00

Elapsed: 00:00:36.83



Faster

Still Index Scan Still Poor Cardinality Estimates





Note any changes in the execution plan or run time with parallel execution.








6 FROM lineorder








14 'CHINA 2',

15 'CHINA 3',

16 'CHINA 4',

17 'CHINA 5',

18 'CHINA 6',

19 'CHINA 7',

20 'CHINA 8',

21 'CHINA 9')




Elapsed: 00:00:19.17



Index Scans Poor Cardinality Estimates



15. Run 15.check_table_stats.sql

Check the table stats.

Are there any issues with the table stats?



TABLE_NAME NUM_ROWS BLOCKS LAST_ANAL

------------------------------ ---------- ---------- ---------

CUSTOMER 270000 3711 10-OCT-14

DATE_DIM 2556 67 10-OCT-14

LINEORDER 53986608 709240 04-MAY-15

PART 800000 9975 26-MAR-15

PROMOTION 946 7 26-MAR-15

SUPPLIER 10 5 26-MAR-15

Supplier only has 10 rows?



16. Run 16.check_supplier_column_stats.sql

Check the column stats on the supplier table.

Are there any issues with the column stats?



TABLE_NAME COLUMN_NAME NUM_DISTINCT HISTOGRAM

------------------------------ ------------------------------ ------------ ---------------

SUPPLIER S_ADDRESS 10 NONE

SUPPLIER S_CITY 10 NONE

SUPPLIER S_NAME 10 NONE

SUPPLIER S_NATION 9 NONE

SUPPLIER S_PHONE 10 NONE

SUPPLIER S_REGION 4 NONE

SUPPLIER S_SUPPKEY 10 NONE

No histograms on supplier



17. Run 17.gather_stats_supplier.sql

Regather stats on the supplier table.



SQL> exec dbms_stats.gather_table_stats(user, 'SUPPLIER', degree=>4);


Elapsed: 00:00:02.70



18. Run 18.check_table_stats.sql

Check the new stats on the supplier table.

Are there any changes?



TABLE_NAME NUM_ROWS BLOCKS LAST_ANAL

------------------------------ ---------- ---------- ---------

CUSTOMER 270000 3711 10-OCT-14

DATE_DIM 2556 67 10-OCT-14

LINEORDER 53986608 709240 04-MAY-15

PART 800000 9975 26-MAR-15

PROMOTION 946 7 26-MAR-15

SUPPLIER 18000 237 04-MAY-15

Accurate row count




Check the new column stats on the supplier table.

Are there any changes?




------------------------------ ------------------------------ ------------ ---------------


SUPPLIER S_CITY 250 FREQUENCY


SUPPLIER S_NATION 25 FREQUENCY


SUPPLIER S_REGION 5 FREQUENCY


Histograms




Run query 3 and note any differences in the execution plan and time.




SQL>





5 FROM lineorder



8 /


---------------- ------------------ ----------------

54160034.00 7714635359678.00 191116713490.00

Elapsed: 00:00:05.89


RWP Training SQL Hands-On ExerciseFaster

Full table scans Better Cardinality Estimates




Run query 4 and note any differences in the execution plan and time.








6 FROM lineorder








14 'CHINA 2',

15 'CHINA 3',

16 'CHINA 4',

17 'CHINA 5',

18 'CHINA 6',

19 'CHINA 7',

20 'CHINA 8',

21 'CHINA 9')




25 /

Elapsed: 00:00:19.90



Still Index Scan Still Poor Cardinality Estimates



22. Run 22.column_group_supplier.sql

Create a column group on the supplier table and regather stats.



SQL> select dbms_stats.create_extended_stats

(user, 'SUPPLIER', '(S_REGION,S_NATION,S_CITY)') col_group from dual;

COL_GROUP

------------------------------

SYS_STU1_R3P$YT6XRQT9PK4LXF74J



Elapsed: 00:00:01.86




Run query 4.








6 FROM lineorder








14 'CHINA 2',

15 'CHINA 3',

16 'CHINA 4',

17 'CHINA 5',

18 'CHINA 6',

19 'CHINA 7',

20 'CHINA 8',

21 'CHINA 9')




25 /

Elapsed: 00:00:21.11



Still Index ScanStill Poor Cardinality Estimates




------------------------------ ------------------------------ ------------ ---------------

SUPPLIER SYS_STU1_R3P$YT6XRQT9PK4LXF74J 250 NONE








No Histogram



25. Run 25.gather_stats_supplier.sql

Regather stats on the supplier table.



SQL> @25.gather_stats_supplier.sql

SQL>



Elapsed: 00:00:02.57




------------------------------ ------------------------------ ------------ ---------------

SUPPLIER SYS_STU1_R3P$YT6XRQT9PK4LXF74J 250 FREQUENCY








Histogram




Run query 4.








6 FROM lineorder








14 'CHINA 2',

15 'CHINA 3',

16 'CHINA 4',

17 'CHINA 5',

18 'CHINA 6',

19 'CHINA 7',

20 'CHINA 8',

21 'CHINA 9')




25 /

Elapsed: 00:00:01.28


RWP Training SQL Hands-On Exercise1 second

Full table scan Better Cardinality Estimates

rwp training sql hands-on exercise - oracle...rwp training sql hands-on exercise table_name...

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