Connor McDonald Partitioning

NOTE itty bitty fonts in this presentation SQL> exec sample_font Can you read this ? 1

Connor McDonald OracleDBA co.uk 2

bio slide 4

Connor McDonald

why ? ...now 7

version 8.0 8

a personal history 11

80's 12

Walker Interactive 15

Jeff Walker... 16

20G 17

$200 per gigabyte per month 19

Storage is expensive 20

Archive 21

90's 23

JBOD 25

Storage is cheap ! 26

Archive 27

Archive 28

1992 1996 1999

00's 31

disk is even cheaper.... 32

....but 34

keep everything ! 36

JBOD 37

HBA Infiniband Filer Cache Fibre Channel etc 39

Storage is cheap ! 40

Storage Storage is is expensive cheap ! 41

CEO 42

brings us to today... 43

ILM 44

Information Lifecycle Management 45

keep everything .... cheaply 46

put the new stuff on good storage keep everything .... cheaply put the old stuff on crappy storage 47

split stuff up 48

basics 50

range partitioning since 8.0 51

SALES 2009 2010 2011 2012 52

provocative statement 53

"all applications are (time) windows on data" http://thehelsinkideclaration.blogspot.com/ 54

corollary: everyone can benefit from range partitions 55

time the most common 56

SQL> create table DEMO 2 ( tstamp timestamp(6) not null, 3 empno number(10) not null, 4 ename varchar2(10) not null, 5 deptno varchar2(10) not null 6 ) 7 PARTITION BY RANGE (TSTAMP) 8 ( 9 PARTITION p01 VALUES LESS THAN 10 (TIMESTAMP' 2010-01-01 00:00:00'), 11 PARTITION p02 VALUES LESS THAN 12 (TIMESTAMP' 2010-02-01 00:00:00'), 13 PARTITION p03 VALUES LESS THAN 14 (TIMESTAMP' 2010-03-01 00:00:00'), ... ... 25 PARTITION p13 VALUES LESS THAN 26 (TIMESTAMP' 2011-01-01 00:00:00') 27 ); Table created. 57

SQL> select partition_name pname, 2 partition_position pos, 3 high_value 4 from USER_TAB_PARTITIONS 5 where table_name = 'DEMO'; PNAME POS HIGH_VALUE ----- ---------- ------------------------------- P01 1 TIMESTAMP' 2010-01-01 00:00:00' P02 2 TIMESTAMP' 2010-02-01 00:00:00' P03 3 TIMESTAMP' 2010-03-01 00:00:00' P04 4 TIMESTAMP' 2010-04-01 00:00:00' P05 5 TIMESTAMP' 2010-05-01 00:00:00' P06 6 TIMESTAMP' 2010-06-01 00:00:00' P07 7 TIMESTAMP' 2010-07-01 00:00:00' P08 8 TIMESTAMP' 2010-08-01 00:00:00' P09 9 TIMESTAMP' 2010-09-01 00:00:00' P10 10 TIMESTAMP' 2010-10-01 00:00:00' P11 11 TIMESTAMP' 2010-11-01 00:00:00' P12 12 TIMESTAMP' 2010-12-01 00:00:00' P13 13 TIMESTAMP' 2011-01-01 00:00:00' 58

range partition boundaries 59

split by upper bound 60

P02 >= 2010-01-01 P02 < 2010-02-01 PARTITION p01 VALUES LESS THAN (TIMESTAMP' 2010-01-01 00:00:00'), PARTITION p02 VALUES LESS THAN (TIMESTAMP' 2010-02-01 00:00:00'), January not February 61

possible benefits 62

performance 63

partition pruning 64

SQL> set autotrace traceonly explain SQL> select * from DEMO 2 where TSTAMP = to_date('11-JUN-2010'); --------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | --------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | | | 1 | PARTITION RANGE SINGLE| | 1 | 7 | 7 | |* 2 | TABLE ACCESS FULL | DEMO | 1 | 7 | 7 | --------------------------------------------------------------- 65

SQL> select partition_name pname, 2 partition_position pos, 3 high_value 4 from user_tab_partitions 5 where table_name = 'DEMO'; PNAME POS HIGH_VALUE ----- ---------- ------------------------------- P01 1 TIMESTAMP' 2010-01-01 00:00:00' P02 2 TIMESTAMP' 2010-02-01 00:00:00' P03 3 TIMESTAMP' 2010-03-01 00:00:00' P04 4 TIMESTAMP' 2010-04-01 00:00:00' P05 5 TIMESTAMP' 2010-05-01 00:00:00' P06 6 TIMESTAMP' 2010-06-01 00:00:00' P07 7 TIMESTAMP' 2010-07-01 00:00:00' P08 8 TIMESTAMP' 2010-08-01 00:00:00' P09 9 TIMESTAMP' 2010-09-01 00:00:00' P10 10 TIMESTAMP' 2010-10-01 00:00:00' P11 11 TIMESTAMP' 2010-11-01 00:00:00' P12 12 TIMESTAMP' 2010-12-01 00:00:00' P13 13 TIMESTAMP' 2011-01-01 00:00:00' 66

more later... 67

dbms_xplan 68

SQL> explain plan for select .... SQL> select * 2 from table(dbms_xplan.display) 69

SQL> select * 2 from table( 3 dbms_xplan.display( 4 format=>'PARTITION -COST -BYTES')); 70

SQL> select * 2 from table(dbms_xplan.display_awr(...)) 71

SQL> select ... SQL> select * 2 from table(dbms_xplan.display_cursor) 72

SQL> select * 2 from table(dbms_xplan.display_plan_baseline) 73

back to range partitioning 74

add / drop move cache control maintenance rebuild backup / read-only compress 75

partition loss availability recovery a little dubious.... 76

multi-column range 77

SQL> create table SALES_DATA 2 ( yyyy number(4) not null, 3 mm number(2) not null, 4 sales_id varchar2(10) not null, 5 amount number(10) 6 ) 7 PARTITION BY RANGE (yyyy, mm) 8 ( 9 PARTITION p01 VALUES LESS THAN (2010,02), 10 PARTITION p02 VALUES LESS THAN (2010,03), 11 PARTITION p03 VALUES LESS THAN (2010,04) ... ... 22 ) 23 / Table created. 78

tiebreaker 79

not multi dimension 80

SQL> create table MOBILE_PHONE 2 ( start_day date not null, 3 end_day date not null, 4 account_id varchar2(10) not null, 5 calls number(10) 6 ) 7 PARTITION BY RANGE (start_day, end_day) 8 ( 9 PARTITION p01 VALUES LESS THAN 10 ('01-FEB-2010','01-FEB-2010'), 11 PARTITION p02 VALUES LESS THAN 12 ('01-MAR-2010','01-MAR-2010'), 13 PARTITION p03 VALUES LESS THAN 14 ('01-APR-2010','01-APR-2010') 15 ) 16 / Table created. 81

SQL> select sum(calls) 2 from MOBILE_PHONE 3 where START_DAY= '12-FEB-2010'; ---------------------------------------------------------------- | Id | Operation | Name | Pstart| Pstop | ---------------------------------------------------------------- | 0 | SELECT STATEMENT | | | | | 1 | SORT AGGREGATE | | | | | 2 | PARTITION RANGE SINGLE| | 3 | 3 | |* 3 | TABLE ACCESS FULL | MOBILE_PHONE | 3 | 3 | ---------------------------------------------------------------- 82

SQL> select sum(calls) 2 from MOBILE_PHONE 3 where END_DAY= '12-FEB-2010'; ---------------------------------------------------------------------- | Id | Operation | Name | Pstart| Pstop | ---------------------------------------------------------------------- | 0 | SELECT STATEMENT | | | | | 1 | SORT AGGREGATE | | | | | 2 | PARTITION RANGE ALL | | 1 | 3 | |* 3 | TABLE ACCESS FULL | MOBILE_PHONE | 1 | 3 | ---------------------------------------------------------------------- 83

9 PARTITION p01 VALUES LESS THAN 10 ('01-FEB-2010','01-FEB-2010'), 11 PARTITION p02 VALUES LESS THAN 12 ('01-MAR-2010','01-MAR-2010'), 13 PARTITION p03 VALUES LESS THAN 14 ('01-APR-2010','01-APR-2010') SQL> insert into MOBILE_PHONE 2 values ('07-FEB-2010','12-FEB-2010'); SQL> insert into MOBILE_PHONE 2 values ('23-JAN-2010','12-FEB-2010'); SQL> insert into MOBILE_PHONE 2 values ('17-MAR-2010','12-FEB-2010'); 84

better in 11g 85

SQL> select sum(calls) 2 from MOBILE_PHONE 3 where END_DAY= '12-FEB-2010'; ---------------------------------------------------------------------- | Id | Operation | Name | Pstart| Pstop | ---------------------------------------------------------------------- | 0 | SELECT STATEMENT | | | | | 1 | SORT AGGREGATE | | | | | 2 | PARTITION RANGE MULTI-COLUMN| |KEY(MC)|KEY(MC)| |* 3 | TABLE ACCESS FULL | MOBILE_PHONE |KEY(MC)|KEY(MC)| ---------------------------------------------------------------------- 86

hash partitioning since 8.1 87

big stuff is a pain 88

"metapoor" 89

possible benefits 92

manageability 93

move backup etc 95

insertion performance 96

"buffer busy waits" 97

"enq: HW - contention" 98

"read by other session" 99

less relevant nowadays for tables 101

ASSM 102

automatic segment space management 103

SQL> CREATE TABLESPACE DEMO 2 DATAFILE '...' SIZE 20G 3 EXTENT MANAGEMENT LOCAL 4 SEGMENT SPACE MANAGEMENT AUTO; 104

...but still very important see later 106

SQL> create table T 2 ( x number(10) ) 3 partition by hash ( x ) 4 partitions 8 5 / Table created. 107

even spread of values 108

SQL> create table T 2 ( x number(10) ) 3 partition by hash ( x ) 4 partitions 8 5 / Table created. 1,2,3,4 .... 100000 SQL> insert into T 2 select level 3 from dual connect by level <= 100000 4 / 100000 rows created. 109

SQL> select DBMS_ROWID.ROWID_OBJECT(rowid) ptn, 2 count(*) 3 from T 4 group by DBMS_ROWID.ROWID_OBJECT(rowid); PTN COUNT(*) ---------- ---------- 72166 12381 72167 12628 72161 12603 72162 12574 72163 12581 72168 12382 72164 12508 72165 12342 110

predicting hash target 111

SQL> select dbms_rowid.ROWID_OBJECT(rowid) ptn, 2 count(*) 3 from T SQL> select ora_hash(x,7), count(*) 4 2 from t dbms_rowid.ROWID_OBJECT(rowid) group by 5 3 group by ora_hash(x,7) order by 2; 4 order by 2; PTN COUNT(*) ---------- ---------- ORA_HASH(X,7) COUNT(*) ------------- 12342 73535 ---------- 73536 4 12381 12342 73538 5 12382 12381 remember these 73534 7 12508 12382 73532 3 12574 12508 73533 1 12581 12574 73531 2 12603 12581 73537 0 12628 12603 6 12628 112

the power of 2 rule 113

SQL> create table T 2 ( x number(10) ) 3 partition by hash ( x ) 4 partitions 4 | 8 | 16 | 32 ... 5 / Table created. 114

SQL> select DBMS_ROWID.ROWID_OBJECT(rowid) ptn, 2 count(*) 3 from T 4 group by DBMS_ROWID.ROWID_OBJECT(rowid); PTN COUNT(*) ---------- ---------- 72166 12381 72167 12628 72161 12603 72162 12574 72163 12581 72168 12382 72164 12508 72165 12342 115

SQL> create table T 2 ( x number(10) ) 3 partition by hash ( x ) 4 partitions 5 5 / Table created. SQL> insert into T 2 select level 3 from dual connect by level <= 100000 4 / 100000 rows created. 116

SQL> select DBMS_ROWID.ROWID_OBJECT(rowid) ptn, 2 count(*) 3 from T 4 group by DBMS_ROWID.ROWID_OBJECT(rowid); PTN COUNT(*) ---------- ---------- 72174 12342 72172 25209 72171 24955 72173 24890 72170 12603 117

why ? 118

deliberately for maintenance... 119

Task: from 5 to 8 partitions 120

"classical" redistribution 121

"every" row moves 122

SQL> select count(*) 2 from T 3 where ora_hash(x,4) != ora_hash(x,7); COUNT(*) ---------- 87564 123

"smart" redistribution 124

SQL> select DBMS_ROWID.ROWID_OBJECT(rowid) ptn, 2 count(*) 3 from T 4 group by DBMS_ROWID.ROWID_OBJECT(rowid); PTN COUNT(*) ---------- ---------- 72174 12342 72172 25209 72171 24955 72173 24890 pick one 72170 12603 5 rows selected. 125

SQL> alter table T add partition; Table altered. SQL> select dbms_rowid.ROWID_OBJECT(rowid) ptn, 2 count(*) 3 from T 4 group by dbms_rowid.ROWID_OBJECT(rowid); PTN COUNT(*) ---------- ---------- 73515 25209 73516 24890 73517 12342 73519 12381 73518 12574 73513 12603 126

SQL> alter table T add partition; Table altered. SQL> select dbms_rowid.ROWID_OBJECT(rowid) ptn, 2 count(*) 3 from T 4 group by dbms_rowid.ROWID_OBJECT(rowid); PTN COUNT(*) ---------- ---------- 73516 24890 73517 12342 73519 12381 73518 12574 73521 12628 73520 12581 73513 12603 127

SQL> alter table T add partition; Table altered. SQL> select dbms_rowid.ROWID_OBJECT(rowid) ptn, 2 count(*) 3 from T 4 group by dbms_rowid.ROWID_OBJECT(rowid); PTN COUNT(*) ---------- ---------- 73517 12342 73523 12382 73522 12508 73519 12381 73518 12574 73521 12628 73520 12581 73513 12603 128

only 1 partition "effort" 129

same for coalesce partition 130

handling a small number of values 131

SQL> create table ... ... 20 values less than ('WB'), 21 values less than ('QLE'), 22 values less than ('SB'), 23 values less than ('VID'), range fiddly.... 132

SQL> select state, ora_hash(state,7) hash 2 from AUST; STATE HASH ----- ---- WA 2 SA 5 NSW 3 VIC 5 hash ... poor distribution 133

list version 9 134

SQL> create table SALES_DATA 2 ( sales_id varchar2(10) not null, 3 location varchar2(3) not null, 4 amount number(10) 5 ) 6 PARTITION BY LIST (location) 7 ( 8 PARTITION NSW VALUES ('NSW'), 9 PARTITION WA VALUES ('WA'), 10 PARTITION QLD VALUES ('QLD'), 11 PARTITION SA VALUES ('SA'), 12 PARTITION VIC VALUES ('VIC'), 13 PARTITION TERR VALUES ('ACT','NT'), 14 PARTITION DREGS VALUES (DEFAULT) 15 ) 18 / Table created. 135

think carefully on DEFAULT add versus split 136

sometimes one level is not enough 137

ranges unevenly distributed 140

deletion of older data 2009 2010 2011 2012 141

composite partitions 142

composite (range + hash) since 8.1 143

SQL> create table COMP 2 ( tstamp timestamp(6) not null, 3 empno number(10) not null, 4 ename varchar2(10) not null, 5 deptno varchar2(10) not null 6 ) 7 PARTITION BY RANGE (TSTAMP) 8 SUBPARTITION BY LIST (deptno) 9 ( 10 PARTITION p01 VALUES LESS THAN 11 (TIMESTAMP' 2010-01-01 00:00:00') 12 (SUBPARTITION p01_d1 VALUES (1), 13 SUBPARTITION p01_d2 VALUES (2), 14 SUBPARTITION p01_d3 VALUES (3), 15 SUBPARTITION p01_d4 VALUES (4)), 16 PARTITION p02 VALUES LESS THAN 17 (TIMESTAMP' 2010-02-01 00:00:00') 18 (SUBPARTITION p02_d1 VALUES (1), 19 SUBPARTITION p02_d2 VALUES (2), 20 SUBPARTITION p02_d3 VALUES (3), 21 SUBPARTITION p02_d4 VALUES (4)), ..... 144

30 PARTITION p11 VALUES LESS THAN 31 (TIMESTAMP' 2010-11-01 00:00:00') 32 (SUBPARTITION p01_d1 VALUES (1,2), 33 SUBPARTITION p01_d2 VALUES (3,4), 34 PARTITION p12 VALUES LESS THAN 35 (TIMESTAMP' 2010-12-01 00:00:00') 36 PARTITION p13 VALUES LESS THAN 37 (TIMESTAMP' 2011-01-01 00:00:00') ..... recall: coalesce partition 145

long DDL ..... 146

subpartition templates 147

SQL> create table COMP 2 ( tstamp timestamp(6) not null, 3 empno number(10) not null, 4 ename varchar2(10) not null, 5 deptno varchar2(10) not null 6 ) 7 PARTITION BY RANGE (TSTAMP) 8 SUBPARTITION BY LIST (deptno) 9 SUBPARTITION TEMPLATE 10 (SUBPARTITION d1 VALUES (1), 11 SUBPARTITION d2 VALUES (2), 12 SUBPARTITION d3 VALUES (3), implicit 13 SUBPARTITION d4 VALUES (4)) subpar's 14 ( 15 PARTITION p01 VALUES LESS THAN 16 (TIMESTAMP' 2010-01-01 00:00:00'), 17 PARTITION p02 VALUES LESS THAN 18 (TIMESTAMP' 2010-02-01 00:00:00'), 19 .... 148

SQL> select partition_name pname, 2 partition_position pos, 3 high_value 4 from USER_TAB_PARTITIONS 5 where table_name = 'COMP'; PNAME POS HIGH_VALUE ---------- ---------- -------------------------------- P01 1 TIMESTAMP' 2010-01-01 00:00:00' P02 2 TIMESTAMP' 2010-02-01 00:00:00' P03 3 TIMESTAMP' 2010-03-01 00:00:00' P04 4 TIMESTAMP' 2010-04-01 00:00:00' P05 5 TIMESTAMP' 2010-05-01 00:00:00' P06 6 TIMESTAMP' 2010-06-01 00:00:00' P07 7 TIMESTAMP' 2010-07-01 00:00:00' P08 8 TIMESTAMP' 2010-08-01 00:00:00' ... 149

SQL> select subpartition_name pname, 2 subpartition_position pos, 3 high_value 4 from USER_TAB_SUBPARTITIONS 5 where table_name = 'COMP' 6 order by 1,2; PNAME POS HIGH_VALUE ---------- ---------- ---------------------- P01_D1 1 '1' P01_D2 2 '2' P01_D3 3 '3' P01_D4 4 '4' P02_D1 1 '1' P02_D2 2 '2' P02_D3 3 '3' P02_D4 4 '4' P03_D1 1 '1' auto named for ... subpar templates ... 150

partitions logical or physical 151

composite (range + list) since 9 152

composite (anything + anything) since 11 153

interval partitioning 11g 154

the problem with ranges.... 155

... they are a range 156

require maintenance 157

25 PARTITION p13 VALUES LESS THAN 26 (TIMESTAMP' 2011-01-01 00:00:00') 27 ); SQL> insert into DEMO 2 values ( to_date('01-JAN-2014'), .... ); insert into DEMO * ERROR at line 1: ORA-14400: inserted partition key does not map to any partition 158

insurance policy 159

25 PARTITION p13 VALUES LESS THAN 26 (TIMESTAMP' 2011-01-01 00:00:00') 26 PARTITION pmax VALUES LESS THAN 27 (MAXVALUE) 28 ); magic value SQL> insert into DEMO 2 values ( to_date('01-JAN-2014'), .... ); 1 row created. 160

why MAXVALUE might hurt (part 1) 161

split not add 162

SQL> alter table DEMO split partition PMAX 2 at ( TIMESTAMP' 2012-02-01 00:00:00') 3 into ( partition p14, partition pmax ) 4 / Table altered. 163

hoping for empty partition 164

"fast split" partition 165

index hassles see later... 166

"solved" in 11g 167

interval partitioning 169

SQL> create table DEMO 2 ( tstamp timestamp(6) not null, 3 empno number(10) not null, 4 ename varchar2(10) not null, 5 deptno varchar2(10) not null 6 ) 7 PARTITION BY RANGE (TSTAMP) 8 INTERVAL( NUMTOYMINTERVAL(1,'MONTH')) 9 ( 10 PARTITION P00 VALUES LESS THAN 11 (TIMESTAMP' 2010-01-01 00:00:00') 11 ); Table created. 170

partitions created as required 171

SQL> select PARTITION_NAME, HIGH_VALUE 2 from user_tab_partitions 3 where table_name = 'DEMO'; PARTITION_NAME HIGH_VALUE ------------------------- -------------------------------- P00 TIMESTAMP' 2010-01-01 00:00:00' SQL> insert into DEMO 2 values ( to_date('12-DEC-2011'),....); 1 row created. SQL> select PARTITION_NAME, HIGH_VALUE 2 from user_tab_partitions 3 where table_name = 'DEMO'; PARTITION_NAME HIGH_VALUE ------------------------- -------------------------------- P00 TIMESTAMP' 2010-01-01 00:00:00' SYS_P362 TIMESTAMP' 2012-01-01 00:00:00' 172

gaps allowed 173

range partition boundaries Length Length Length 174

partition name control lost can rename.... 175

convert range to interval 176

original range version SQL> alter table DEMO 2 SET INTERVAL ( NUMTOYMINTERVAL(1,'MONTH') ); Table altered. 177

SQL> insert into DEMO 2 values ( to_date('01-JAN-2017'),....); 1 row created. 178

SQL> select partition_name pname, 2 partition_position pos, 3 high_value 4 from user_tab_partitions 5 where table_name = 'DEMO'; PNAME POS HIGH_VALUE ------------ ---------- -------------------------------- P01 1 TIMESTAMP' 2010-01-01 00:00:00' P02 2 TIMESTAMP' 2010-02-01 00:00:00' P03 3 TIMESTAMP' 2010-03-01 00:00:00' P04 4 TIMESTAMP' 2010-04-01 00:00:00' ... P10 10 TIMESTAMP' 2010-10-01 00:00:00' P11 11 TIMESTAMP' 2010-11-01 00:00:00' P12 12 TIMESTAMP' 2010-12-01 00:00:00' P13 13 TIMESTAMP' 2011-01-01 00:00:00' SYS_P1091 14 TIMESTAMP' 2017-02-01 00:00:00' 179

but be careful ... 180

hybrid range range range interval 181

is it range or interval ? 182

SQL> desc DBA_TAB_PARTITIONS Name Null? Type ----------------------- -------- ---------------- TABLE_OWNER VARCHAR2(30) TABLE_NAME VARCHAR2(30) COMPOSITE VARCHAR2(3) PARTITION_NAME VARCHAR2(30) SUBPARTITION_COUNT NUMBER HIGH_VALUE LONG ? HIGH_VALUE_LENGTH PARTITION_POSITION TABLESPACE_NAME NUMBER NUMBER VARCHAR2(30) ... LOGGING VARCHAR2(7) COMPRESSION VARCHAR2(8) COMPRESS_FOR VARCHAR2(18) NUM_ROWS NUMBER BUFFER_POOL VARCHAR2(7) GLOBAL_STATS VARCHAR2(3) USER_STATS VARCHAR2(3) 183

SQL> select o.subname, 2 decode(bitand(tp.flags,32768), 3 32768,'YES','NO') interval 4 from SYS.TABPART$ tp, SYS.OBJ$ o 6 where tp.obj# = o.obj# 6 and o.name = 'DEMO'; SUBNAME INT ------------------------------ --- P01 NO P02 NO P03 NO P04 NO P05 NO ... P11 NO P12 NO P13 NO SYS_P1091 YES 14 rows selected. 184

fixed in 11.2 185

high range value gets "stuck" 186

SQL> insert into DEMO 2 values ( to_date('01-JAN-2017'),...); 1 row created. SQL> insert into DEMO 2 values ( to_date('01-JAN-2016'),...); 1 row created. 187

SQL> select partition_name pname, 2 partition_position pos, 3 high_value 4 from user_tab_partitions 5 where table_name = 'DEMO'; PNAME POS HIGH_VALUE ------------ ---------- ------------------------------- P01 1 TIMESTAMP' 2010-01-01 00:00:00' P02 2 TIMESTAMP' 2010-02-01 00:00:00' P03 3 TIMESTAMP' 2010-03-01 00:00:00' P04 4 TIMESTAMP' 2010-04-01 00:00:00' ... P13 13 TIMESTAMP' 2011-01-01 00:00:00' SYS_P1112 14 TIMESTAMP' 2016-02-01 00:00:00' SYS_P1111 15 TIMESTAMP' 2017-02-01 00:00:00' 188

SQL> alter table DEMO drop partition P01; Table altered. SQL> alter table DEMO drop partition P02; Table altered. SQL> alter table DEMO drop partition P13; alter table DEMO drop partition P13 * ERROR at line 1: ORA-14758: Last partition in the range section cannot be dropped 189

Length Length Length 190

workarounds (maybe) unpleasant.... 191

SQL> alter table DEMO set interval ( ); Table altered. SQL> alter table DEMO 2 set interval (NUMTOYMINTERVAL(1,'MONTH')); Table altered. 192

SQL> alter table DEMO merge partitions 2 for (TIMESTAMP' 2010-12-30 00:00:00'), 3 for (TIMESTAMP' 2016-01-10 00:00:00'); Table altered. 193

11.2 194

SQL> alter table DEMO 2 set interval (NUMTOYMINTERVAL(1,'MONTH')); Table altered. 195

why MAXVALUE might hurt (part 2) 196

SQL> create table DEMO 2 ( tstamp timestamp(6) not null, 3 empno number(10) not null, 4 ename varchar2(10) not null, 5 deptno varchar2(10) not null 6 ) 7 PARTITION BY RANGE (TSTAMP) 8 ( 9 PARTITION p01 VALUES LESS THAN 10 (TIMESTAMP' 2010-01-01 00:00:00'), ... 25 partition PMAX values less than (MAXVALUE) 26 ) 27 / Table created. 197

SQL> alter table DEMO 2 set interval ( NUMTOYMINTERVAL(1,'MONTH') ); * ERROR at line 1: ORA-14759: SET INTERVAL is not legal on this table. 198

explain plan anomaly 199

INTERVAL = "1 million partitions" 200

SQL> create table DEMO 2 ( tstamp timestamp(6) not null, 3 empno number(10) not null, 4 ename varchar2(10) not null, 5 deptno varchar2(10) not null 6 ) 7 PARTITION BY RANGE (TSTAMP) 8 INTERVAL( NUMTOYMINTERVAL(1,'MONTH')) 9 ( 10 PARTITION P00 VALUES LESS THAN 11 (TIMESTAMP' 2010-01-01 00:00:00') 12 ); Table created. 201

SQL> select * from DEMO; ------------------------------------------------------------ | Id | Operation | Name | Rows | Pstart| Pstop | ------------------------------------------------------------ | 0 | SELECT STATEMENT | | 1 | | | | 1 | PARTITION RANGE ALL| | 1 | 1 |1048575| | 2 | TABLE ACCESS FULL | DEMO | 1 | 1 |1048575| ------------------------------------------------------------ 202

partitioned tables ... the bigger picture 203

SALES SQL> desc SALES Name Null? Type -------------------- -------- -------------- SALE_DATE NOT NULL DATE ... 2009 2010 2011 2012 SALES_ITEMS SQL> desc SALES_ITEMS Name Null? Type -------------------- -------- ----------- SALE_ID NOT NULL NUMBER(12) ITEM_ID NOT NULL NUMBER(12) ... 204

reference partitions 11g 205

SQL> create table PARENT 2 ( d date not null, 3 p number(10) not null, 4 pad char(10) 5 ) 6 PARTITION BY RANGE (d) 7 ( 8 PARTITION p1 VALUES LESS THAN ( to_date('01-JAN-2010')), 9 PARTITION p2 VALUES LESS THAN ( to_date('01-FEB-2010')), 10 PARTITION p3 VALUES LESS THAN ( to_date('01-MAR-2010')), 11 PARTITION p4 VALUES LESS THAN ( to_date('01-APR-2010')), 12 PARTITION p5 VALUES LESS THAN ( to_date('01-MAY-2010')), 13 PARTITION p6 VALUES LESS THAN ( to_date('01-JUN-2010')), 14 PARTITION p7 VALUES LESS THAN ( to_date('01-JUL-2010')), 15 PARTITION p8 VALUES LESS THAN ( to_date('01-AUG-2010')), 16 PARTITION p9 VALUES LESS THAN ( to_date('01-SEP-2010')) 17 ); Table created. SQL> alter table PARENT add primary key ( p ); Table altered. 206

SQL> create table CHILD 2 ( p number(10) not null, 3 c number(10) not null, 4 constraint CHILD_FK foreign key ( p ) 5 references PARENT (p) 6 on delete cascade 7 ) 8 PARTITION BY REFERENCE (CHILD_FK) 9 / Table created. 207

SQL> insert into PARENT 2 select sysdate+rownum, rownum, rownum 3 from dual connect by level <= 100 4 / 100 rows created. SQL> insert into CHILD 2 select rownum, rownum 3 from dual connect by level <= 100 4 / 100 rows created. 208

SQL> exec dbms_stats.gather_table_stats(user,'CHILD'); PL/SQL procedure successfully completed. SQL> select partition_name, num_rows 2 from USER_TAB_PARTITIONS 3 where table_name = 'CHILD'; PARTITION_NAME NUM_ROWS ------------------------------ ---------- P1 0 P2 0 P3 0 P4 0 P5 9 P6 31 P7 30 P8 30 P9 0 209

seems good .... but 210

null SQL> create table CHILD 2 ( p number(10), 3 c number(10), 4 constraint CHILD_FK foreign key ( p ) 5 references PARENT (p) 6 ) 7 PARTITION BY REFERENCE (CHILD_FK) 8 / PARTITION BY REFERENCE (CHILD_FK) * ERROR at line 7: ORA-14652: reference partitioning foreign key is not supported 211

SQL> create table PARENT 2 ( d date not null, 3 p number(10) not null, 4 pad char(10) 5 ) 6 PARTITION BY RANGE (d) 7 INTERVAL( NUMTOYMINTERVAL(1,'MONTH')) 8 ( PARTITION VALUES LESS THAN ( to_date('01-JAN-2010')) ); Table created. SQL> create table CHILD 2 ( p number(10) not null, 3 c number(10) not null, 4 constraint CHILD_FK foreign key ( p ) 5 references PARENT (p) 6 on delete cascade 7 ) 8 PARTITION BY REFERENCE (CHILD_FK); create table CHILD * ERROR at line 1: ORA-14659: Partitioning method of the parent table is not supported 212

but the following "works".... 213

SQL> alter table PARENT 2 set INTERVAL( NUMTOYMINTERVAL(1,'MONTH')); Table altered. SQL> insert into PARENT values (sysdate+1000,-1,'x'); 1 row created. SQL> select partition_name 2 from user_tab_partitions pk=-1 3 where table_name = 'PARENT'; PARTITION_NAME ------------------------------ SYS_P1196 P1 P2 P3 ... 214

SQL> insert into CHILD values (-1,0); insert into CHILD values (-1,0) * ERROR at line 1: ORA-14401: inserted partition key is outside specified partition 215

dropping requires order 216

SQL> drop table PARENT; drop table PARENT * ERROR at line 1: ORA-02449: unique/primary keys in table referenced by foreign keys SQL> drop table PARENT cascade constraints; drop table PARENT cascade constraints * ERROR at line 1: ORA-14656: cannot drop the parent of a reference- partitioned table 217

Suboptimal Query when Gather Partition Stats on Reference Partitioned Wrong Results In 11g On Reference Partitioned Table ORA-7445[KKPAMDINFO] ON SELECT AGAINST A REFERENCE PARTITIONED TABLE its a very new feature Drop of reference partition not allowed (ORA-2266) with FK between siblings UNIQUE INDEX NOT WORKING PROPERLY ON PARTITIONED BY REFERENCE TABLE ALLOW DROP PARTITION TO SUCCEED ON REFERENCED PARTITION WITHOUT CORRUPTING DATA. 218

Part 2 indexes on partitioned tables 219

SALES 2009 2010 2011 2012 SQL> create index SALES_IX on SALES ( CUSTOMER ); 221

2009 2010 2011 2012 222

"global" index 223

big....really big extended rowid 224

ILM issues 225

2009 2010 2011 2012 SQL> alter table SALES drop partition SALES_2009 226

SQL> create index DEMO_IX on DEMO ( empno ); Index created. SQL> select status 2 from user_indexes 3 where index_name = 'DEMO_IX'; STATUS -------- VALID SQL> select * from DEMO where empno = 123; --------------------------------------------------------------------- | Id | Operation | Name |Pstart| Pstop | -------------------------------------------------------------------- | 0 | SELECT STATEMENT | | | | | 1 | TABLE ACCESS BY GLOBAL INDEX ROWID| DEMO |ROWID | ROWID | |* 2 | INDEX RANGE SCAN | DEMO_IX | | | --------------------------------------------------------------------- 227

SQL> alter table DEMO drop partition P06; Table altered. SQL> select status 2 from user_indexes 3 where index_name = 'DEMO_IX'; STATUS -------- UNUSABLE SQL> select * from DEMO where empno = 123; ------------------------------------------------------------ | Id | Operation | Name | Rows | Pstart| Pstop | ------------------------------------------------------------ | 0 | SELECT STATEMENT | | 50 | | | | 1 | PARTITION RANGE ALL| | 50 | 1 | 13 | |* 2 | TABLE ACCESS FULL | DEMO | 50 | 1 | 13 | ------------------------------------------------------------ 228

SQL> select value 2 from v$parameter 3 where name = 'skip_unusable_indexes'; VALUE ------------------------------ TRUE 229

keep the index valid 230

2009 2010 2011 2012 SQL> alter table SALES drop partition SALES_2009 2 update indexes; 231

undo large delete redo 232

merge split similar issues exchange 233

an alternative 234

"local" index 235

2009 2010 2011 2012 SQL> create index SALES_IX ON SALES ( CUSTOMER ) 2 LOCAL; 236

smaller chunks 237

smaller rowid's 238

2009 2010 2011 2012 SQL> alter table SALES drop partition SALES_2009; 239

SQL> create index DEMO_IX on DEMO ( empno ) LOCAL; Index created. SQL> select partition_name, status 2 from user_ind_partitions 3 where index_name = 'DEMO_IX'; PARTITION_NAME STATUS ------------------------------ ------- P01 USABLE P02 USABLE P03 USABLE P04 USABLE P05 USABLE P06 USABLE P07 USABLE ... 240

SQL> alter table DEMO drop partition P06; Table altered. SQL> select partition_name, status 2 from user_ind_partitions 3 where index_name = 'DEMO_IX'; PARTITION_NAME STATUS ------------------------------ ------- P01 USABLE P02 USABLE P03 USABLE P04 USABLE P05 USABLE P06 USABLE P07 USABLE ... 241

awesome for ILM 242

handlng old data 243

2009 2010 2011 2012 SQL> alter table SALES move partition SALES_2009 2 COMPRESS; 244

RMAN 2009 2010 2011 2012 SQL> alter table SALES move partition SALES_2009 2 TABLESPACE CRAPPY_OLD_DISK; SQL> alter tablespace CRAPPY_OLD_DISK READ ONLY; 245

11.2 very cool 246

"segment-less" segments 247

2009 2010 2011 2012 SQL> alter index SALES_IX partition SALES_IX_2009 2 UNUSABLE; 248

handlng new data 249

2010 2011 2013 2012 2013 SQL> alter table SALES exchange 2 partition SALES_2013 with 3 table NEW_SALES; 250

local = good

global = bad 252

NO ! 253

different "target audience" 254

SQL> create index SALES_IX on SALES ( CUSTOMER ) LOCAL; 123 123 123 123 2009 2010 2011 2012 SQL> select * 2 from SALES 3 where CUSTOMER = 123; 255

can be much much worse... 256

WA VIC WA VIC WA VIC WA VIC 2009 2010 2011 2012 NSW QLD NSW QLD NSW QLD NSW QLD SQL> select * 2 from SALES 3 where CUSTOMER = 123; 257

explain plan 258

SQL> select * from SALES 2 where CUSTOMER= 123; ---------------------------------------------------------------------- | Id | Operation | Name |Pstart | Pstop | ---------------------------------------------------------------------- | 0 | SELECT STATEMENT | | | | | 1 | PARTITION RANGE ALL | | 1 | 13 | | 2 | TABLE ACCESS BY LOCAL INDEX ROWID| SALES | 1 | 13 | |* 3 | INDEX RANGE SCAN | SALES_IX| 1 | 13 | ---------------------------------------------------------------------- 259

SQL> create index SALES_IX on SALES ( CUSTOMER ) LOCAL; 123 123 123 123 2009 2010 2011 2012 SQL> select * 2 from SALES 3 where CUSTOMER = 123; 260

"so global for index lookups then".... 261

NO ! 262

123 2009 2010 2011 2012 SQL> select * 2 from SALES 3 where CUSTOMER = 123 4 and YEAR = 2010; 263

careful design 264

application compromises eg unique keys 265

so far ... "equipartition" 266

SALES SQL> create index SALES_IX ON SALES ( CUSTOMER ) 2 global 3 partition by .... 267

2009 2010 2011 2012 SQL> create index SALES_IX 2 on SALES ( location, empno ) 3 global partition by range ( location ) 4 ( partition p0 values less than (1), 6 partition p1 values less than (2), ... 12 partition pmax values less than (maxvalue) 13 ); Index created. 268

rare .... 269

...one special case 10g+ 270

hash partitioned index 271

recall: hash partitioned tables 272

ASSM concurrency 273

indexes a problem 274

hash partitioned indexes 276

SQL> create index SALES_PK on SALES( TXN_ID ) 2 global partition by hash ( TXN_ID ) 3 partitions 8 4 / Index created. 277

only for equality primary keys 279

beware the NOSORT 280

reference partitions and indexes 281

SALES 2009 2010 2011 2012 SALES_ITEMS 2009 2010 2011 2012 282

take care with ILM 283

SQL> alter table PARENT drop partition P6; Table altered. SQL> select partition_name 2 from user_tab_partitions 3 where table_name = 'CHILD'; PARTITION_NAME ------------------------------ P1 P2 P3 P4 P5 P7 P8 P9 284

SQL> alter table PARENT truncate partition P7; alter table PARENT truncate partition P7 * ERROR at line 1: ORA-02266: unique/primary keys in table referenced by enabled foreign keys SQL> alter table CHILD truncate partition P7; Table truncated. SQL> alter table PARENT truncate partition P7; Table truncated. gap 285

SQL> select index_name, status from user_indexes; INDEX_NAME STATUS ------------------------------ -------- PARENT_PK UNUSABLE CHILD_PK UNUSABLE 286

exchange is difficult... 287

plus more restrictions..... 288

Part 3 partition queries 289

partition pruning 290

efficiency = data required / data scanned 291

SQL> create table DEMO 2 ( tstamp timestamp(6) not null, 3 empno number(10) not null, 4 ename varchar2(10) not null, 5 deptno varchar2(10) not null 6 ) 7 PARTITION BY RANGE (TSTAMP) 8 ( 9 PARTITION p01 VALUES LESS THAN 10 (TIMESTAMP' 2010-01-01 00:00:00'), 11 PARTITION p02 VALUES LESS THAN 12 (TIMESTAMP' 2010-02-01 00:00:00'), 13 PARTITION p03 VALUES LESS THAN 14 (TIMESTAMP' 2010-03-01 00:00:00'), ... ... 25 PARTITION p13 VALUES LESS THAN 26 (TIMESTAMP' 2011-01-01 00:00:00') 27 ); Table created. 292

360 days SQL> insert /*+ APPEND */ into DEMO 2 select trunc(sysdate,'YYYY')+rownum/( 1000000 / 360 ), 3 rownum, 4 rownum, 5 mod(rownum,1000) 6 from dual 7 connect by level <= 1000000 8 / 1000000 rows created. 293

SQL> select * from DEMO 2 where TSTAMP = to_date('01-JUN-2010'); --------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | --------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | | | 1 | PARTITION RANGE SINGLE| | 1 | 7 | 7 | |* 2 | TABLE ACCESS FULL | DEMO | 1 | 7 | 7 | --------------------------------------------------------------- 294

SQL> select * from DEMO 2 where TRUNC(TSTAMP) = to_date('01-JUN-2010'); ------------------------------------------------------------ | Id | Operation | Name | Rows | Pstart| Pstop | ------------------------------------------------------------ | 0 | SELECT STATEMENT | | 10000 | | | | 1 | PARTITION RANGE ALL| | 10000 | 1 | 13 | |* 2 | TABLE ACCESS FULL | DEMO | 10000 | 1 | 13 | ------------------------------------------------------------ 295

static versus dynamic 296

SQL> select * from DEMO 2 where TSTAMP = :b1; --------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | --------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | | | 1 | PARTITION RANGE SINGLE| | 1 | KEY | KEY | |* 2 | TABLE ACCESS FULL | DEMO | 1 | KEY | KEY | --------------------------------------------------------------- 297

lots of power varies by version 298

SQL> select * from DEMO 2 where TSTAMP between to_date('12-JAN-2010') 3 and to_date('07-FEB-2010') 4 or TSTAMP between to_date('03-JUN-2010') 5 and to_date('06-AUG-2010'); ----------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | ----------------------------------------------------------- | 0 | SELECT STATEMENT | | 240K| | | | 1 | PARTITION RANGE OR| | 240K|KEY(OR)|KEY(OR)| |* 2 | TABLE ACCESS FULL| DEMO | 240K|KEY(OR)|KEY(OR)| ----------------------------------------------------------- 299

SQL> select * from DEMO 2 where TSTAMP in (to_date('01-JUN-2010'), 3 to_date('01-DEC-2010')); --------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | --------------------------------------------------------------- | 0 | SELECT STATEMENT | | 2 | | | | 1 | PARTITION RANGE INLIST| | 2 |KEY(I) |KEY(I) | |* 2 | TABLE ACCESS FULL | DEMO | 2 |KEY(I) |KEY(I) | --------------------------------------------------------------- 300

limitations of explain plan 301

SQL> select * from DEMO 2 where TSTAMP in (to_date('01-JUN-2010'), 3 to_date('01-DEC-2010')); --------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | --------------------------------------------------------------- | 0 | SELECT STATEMENT | | 2 | | | | 1 | PARTITION RANGE INLIST| | 2 |KEY(I) |KEY(I) | |* 2 | TABLE ACCESS FULL | DEMO | 2 |KEY(I) |KEY(I) | --------------------------------------------------------------- JUN JUL AUG SEP OCT NOV DEC 302

July SQL> alter table DEMO move partition P08 tablespace USERS; Table altered. SQL> alter tablespace USERS offline; Tablespace altered. SQL> select count(*) from DEMO 2 where TSTAMP in (to_date('01-JUN-2010'), 3 to_date('01-DEC-2010')); COUNT(*) ---------- 1234 303

SQL> select count(*) from DEMO 2 where TSTAMP in (to_date('01-JUN-2010'), 3 to_date('01-JUL-2010')); select count(*) from DEMO * ERROR at line 1: ORA-00376: file 4 cannot be read at this time ORA-01110: data file 4: 'C:ORACLEDB11USERS01.DBF' 304

"NO OP" pruning 305

SQL> select * from DEMO 2 where TSTAMP = to_date('01-JUN-2020'); -------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | -------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | | | 1 | PARTITION RANGE EMPTY| | 1 |INVALID|INVALID| |* 2 | TABLE ACCESS FULL | DEMO | 1 |INVALID|INVALID| -------------------------------------------------------------- 306

pruning lists 307

SQL> create table SALES 2 ( sales_id varchar2(10) not null, 3 location varchar2(3) not null, 4 amount number(10) 5 ) 6 PARTITION BY LIST (location) 7 ( 8 PARTITION NSW VALUES ('NSW'), 9 PARTITION WA VALUES ('WA'), 10 PARTITION QLD VALUES ('QLD'), 11 PARTITION SA VALUES ('SA'), 12 PARTITION VIC VALUES ('VIC'), 13 PARTITION TERR VALUES ('ACT','NT') 14 ) 15 / Table created. 308

SQL> select * from sales 2 where location = 'WA'; --------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | --------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | | | 1 | PARTITION LIST SINGLE| | 1 | KEY | KEY | | 2 | TABLE ACCESS FULL | SALES | 1 | 2 | 2 | --------------------------------------------------------------- 309

SQL> select * from sales 2 where location like 'S%'; --------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | --------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | | | 1 | PARTITION LIST SINGLE| | 1 | KEY | KEY | | 2 | TABLE ACCESS FULL | SALES | 1 | 4 | 4 | --------------------------------------------------------------- 310

SQL> select * from sales 2 where location NOT in ('WA','NSW'); ------------------------------------------------------------ | Id | Operation | Name | Rows | Pstart| Pstop | ------------------------------------------------------------ | 0 | SELECT STATEMENT | | 1 | | | | 1 | PARTITION LIST ALL| | 1 | 1 | 6 | |* 2 | TABLE ACCESS FULL| SALES | 1 | 1 | 6 | ------------------------------------------------------------ 311

pruning composites 312

SQL> create table COMP 2 ( tstamp timestamp(6) not null, 3 empno number(10) not null, 4 ename varchar2(10) not null, 5 deptno varchar2(10) not null 6 ) 7 PARTITION BY RANGE (TSTAMP) 8 SUBPARTITION BY LIST (deptno) 9 SUBPARTITION TEMPLATE 10 (SUBPARTITION d1 VALUES (1), 11 SUBPARTITION d2 VALUES (2), 12 SUBPARTITION d3 VALUES (3), 13 SUBPARTITION d4 VALUES (4)) 14 ( 15 PARTITION p01 VALUES LESS THAN 16 (TIMESTAMP' 2010-01-01 00:00:00'), 17 PARTITION p02 VALUES LESS THAN 18 (TIMESTAMP' 2010-02-01 00:00:00'), 19 .... 313

SQL> select * from COMP 2 where TSTAMP = to_date('01-JUN-2010') 3 and DEPTNO = 2; --------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | --------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | | | | 1 | PARTITION RANGE SINGLE| | 1 | 7 | 7 | | 2 | PARTITION LIST SINGLE| | 1 | 2 | 2 | |* 3 | TABLE ACCESS FULL | COMP | 1 | 26 | 26 | --------------------------------------------------------------- 314

SQL> select * from COMP 2 where DEPTNO = 3; --------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | --------------------------------------------------------------- | 0 | SELECT STATEMENT | | 250K| | | | 1 | PARTITION RANGE ALL | | 250K| 1 | 13 | | 2 | PARTITION LIST SINGLE| | 250K| 3 | 3 | | 3 | TABLE ACCESS FULL | COMP | 250K| KEY | KEY | --------------------------------------------------------------- 315

pruning by subquery 316

SQL> select e.deptno, max(d.empno) 2 from DEMO d, scott.emp e 3 where d.tstamp = e.hiredate 4 and e.sal < 10000 5 group by e.deptno; ------------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | ------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 14 | | | | 1 | HASH GROUP BY | | 14 | | | |* 2 | HASH JOIN | | 14 | | | |* 3 | TABLE ACCESS FULL | EMP | 14 | | | | 4 | PARTITION RANGE SUBQUERY| | 1000K|KEY(SQ)|KEY(SQ)| | 5 | TABLE ACCESS FULL | DEMO | 1000K|KEY(SQ)|KEY(SQ)| ------------------------------------------------------------------- 317

11g maybe 10.2 ? 318

SQL> select e.deptno, max(d.empno) 2 from demo d, scott.emp e 3 where d.tstamp = e.hiredate 4 and e.sal < 10000 5 group by e.deptno; ----------------------------------------------------------------- | Id | Operation | Name | Pstart| Pstop | ----------------------------------------------------------------- | 0 | SELECT STATEMENT | | | | | 1 | HASH GROUP BY | | | | |* 2 | HASH JOIN | | | | | 3 | PART JOIN FILTER CREATE | :BF0000 | | | |* 4 | TABLE ACCESS FULL | EMP | | | | 5 | PARTITION RANGE JOIN-FILTER| |:BF0000|:BF0000| | 6 | TABLE ACCESS FULL | DEMO |:BF0000|:BF0000| ----------------------------------------------------------------- 319

| 3 | PART JOIN FILTER CREATE | :BF0000 | | | |* 4 | TABLE ACCESS FULL | EMP | | | | 5 | PARTITION RANGE JOIN-FILTER| |:BF0000|:BF0000| | 6 | TABLE ACCESS FULL | DEMO |:BF0000|:BF0000| ----------------------------------------------------------------- huh ? 320

bloom filters 321

The Bloom filter...is a space-efficient probabilistic data structure that is used to test whether an element is a member of a set. - Wikipedia 322

wtf ? 323

"b" bits "h" hash functions 324

b0 b1 h1 b2 b3 data h2 b4 h3 b5 b6 b7 325

b0 b1 b2 h1 b3 h2 matching b4 data? h3 b5 b6 b7 330

b0 b1 b2 h1 do the b3 "real" h2 matching work b4 data? h3 b5 b6 b7 331

b0 b1 b2 h1 do the b3 "real" h2 matching work b4 data? h3 b5 b6 b7 332

"meta-poor" 333

"are you joking...try in 6 months" 336

"yes, we have some" 337

false positives possible 339

false negatives impossible 340

they are here to stay.... 341

SQL> alter session set "_bloom_filter_enabled" = false; SQL> alter session set "_bloom_pruning_enabled" = false; 342

other partitioning benefits 343

partition wise join 344

SQL> select d.*, d2.* 2 from DEMO d, DEMO2 d2 3 where d.TSTAMP = d2.TSTAMP; ------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | ------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1003K| | | | 1 | PARTITION RANGE ALL| | 1003K| 1 | 13 | |* 2 | HASH JOIN | | 1003K| | | | 3 | TABLE ACCESS FULL| DEMO | 1000K| 1 | 13 | | 4 | TABLE ACCESS FULL| DEMO2 | 1000K| 1 | 13 | ------------------------------------------------------------- 345

"big deal" 346

meta-poor 347

1000 cars north of Perth 1000 cars south of Perth 349

"replace damaged models at the north yard with matching models from the south yard" 351

SQL> select ... 2 from NORTH n, SOUTH s 3 where n.MODEL = s.MODEL ---------------------------------------------------------------- | Id | Operation | Name | Pstart| Pstop | ---------------------------------------------------------------- | 0 | SELECT STATEMENT | | | | |* 1 | HASH JOIN | | | | | 3 | PARTITION RANGE ALL | | 1 | 2 | | 4 | TABLE ACCESS FULL | NORTH | 1 | 2 | | 5 | PARTITION RANGE ALL | | 1 | 2 | | 6 | TABLE ACCESS FULL | SOUTH | 1 | 2 | ---------------------------------------------------------------- 353

NORTH 4WD SMART CARS SOUTH 4WD SMART CARS 354

partition wise join 355

SQL> select ... 2 from NORTH n, SOUTH s 3 where n.model = s.model ------------------------------------------------------------- | Id | Operation | Name | Rows | Pstart| Pstop | ------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1003K| | | | 1 | PARTITION RANGE ALL| | 1003K| 1 | 2 | |* 2 | HASH JOIN | | 1003K| | | | 3 | TABLE ACCESS FULL| NORTH | 1000K| 1 | 2 | | 4 | TABLE ACCESS FULL| SOUTH | 1000K| 1 | 2 | ------------------------------------------------------------- 356

great parallel benefits 357

SQL> select /*+ PARALLEL(n) PARALLEL(s) */ ... 2 from north n, south s 3 where n.model = s.model ---------------------------------------------------------------------------------------------- | Id | Operation | Name | Pstart| Pstop | TQ |IN-OUT| PQ Distrib | ---------------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | | | | | | | 1 | PX COORDINATOR | | | | | | | | 2 | PX SEND QC (RANDOM) | :TQ10001 | | | Q1,01 | P->S | QC (RAND) | |* 3 | HASH JOIN | | | | Q1,01 | PCWP | | | 4 | PX BLOCK ITERATOR | | 1 | 2 | Q1,01 | PCWC | | | 5 | TABLE ACCESS FULL | NORTH | 1 | 2 | Q1,01 | PCWP | | | 6 | BUFFER SORT | | | | Q1,01 | PCWC | | | 7 | PX RECEIVE | | | | Q1,01 | PCWP | | | 8 | PX SEND BROADCAST LOCAL| :TQ10000 | | | Q1,00 | P->P | BCST LOCAL | | 9 | PX BLOCK ITERATOR | | 1 | 2 | Q1,00 | PCWC | | | 10 | TABLE ACCESS FULL | SOUTH | 1 | 2 | Q1,00 | PCWP | | ---------------------------------------------------------------------------------------------- 358

Slave 1 Slave 2 NORTH 4WD SMART CARS SOUTH 4WD SMART CARS Slave 3 Slave 4 359

partitions must match exactly 360

if not, better in 11g 361

fallback to bloom filter 362

SQL> select ... 2 from NORTH n, SOUTH s 3 where n.model = s.model ---------------------------------------------------------------- | Id | Operation | Name | Pstart| Pstop | ---------------------------------------------------------------- | 0 | SELECT STATEMENT | | | | |* 1 | HASH JOIN | | | | | 2 | PART JOIN FILTER CREATE | :BF0000 | | | | 3 | PARTITION RANGE ALL | | 1 | 2 | | 4 | TABLE ACCESS FULL | NORTH | 1 | 2 | | 5 | PARTITION RANGE JOIN-FILTER| |:BF0000|:BF0000| | 6 | TABLE ACCESS FULL | SOUTH |:BF0000|:BF0000| ---------------------------------------------------------------- 363

if nececssary, brew your own don't assume 364

wrap up 366

all positive 367

know the pitfalls 368

pitfalls # 1 369

SQL> select * from v$option; PARAMETER VALUE -------------------------------------------------- -------- Partitioning TRUE Objects TRUE Real Application Clusters TRUE Advanced replication TRUE Bit-mapped indexes TRUE Connection multiplexing TRUE Connection pooling TRUE Database queuing TRUE Incremental backup and recovery TRUE Instead-of triggers TRUE Parallel backup and recovery TRUE Parallel execution TRUE Parallel load TRUE 370

even in EE 372

worth the cost.... 373

pitfalls # 2 374

boundary cases constraint validation 375

boundary cases statistics gathering 376

boundary cases shared pool 377

boundary cases reference partitions 378

test with sql trace 379

Connor McDonald OracleDBA co.uk 380

ORA-00041 “active time limit exceeded - session terminated” www.oracledba.co.uk 381

Connor McDonald Partitioning

by InSync Conference on Aug 15, 2010

Accessibility

Categories

Upload Details

Usage Rights

Statistics

Connor McDonald Partitioning Presentation Transcript