I have to do the data base partition testing, i created the interval partition to the table now if i move the clock for testing, the new partitions are not getting created? Still it is showing the old partitions. Any idea how to resolve this? How to check whether table is range partitioned or interval partitioned in oracle database?
After using the below code for the partition deletion i am getting interval partitioned table as range partitioned.
SQL> create or replace procedure partition_delete(var in int) AS
2 v Date := SYSDATE;
3 i number;
4 occurance number;
5 l_drop_sql varchar2(2000);
6 BEGIN
7 execute immediate ' alter table "sch1"."AUDITS" set interval ()';
8 execute immediate ' alter table "sch1"."ALERTAUDITS" set interval ()';
9 -- select the tables that starts with either A or L having cfcc as table owner
10 for curs in ( select table_owner,table_name,partition_name,high_value from dba_tab_partitions where table_owner='owner' and REGEXP_LIKE (table_name,'^(A|L)')) LOOP
11 EXECUTE IMMEDIATE 'SELECT ' || curs.high_Value || ' FROM dual' INTO v; -- Conversion of high_value from long to date
12 select round(SYSDATE - v) into i from dual; -- finding the difference between current date and partition creation date
13 select count(*) into occurance from dba_tab_partitions where table_name=curs.table_name; -- Finding the no of existing partitions to the particular table
14 -- occurance>1 indicates table having only one partition is not getting deleted
15 if i > var and occurance > 1 then
16 dbms_output.put_line('The no of days are '||i);
17 dbms_output.put_line('The table name and partition name are '||curs.table_name||'and'||curs.partition_name);
18 l_drop_sql :='alter table "'||curs.table_owner||'"."'||curs.table_name||'" drop partition '||curs.partition_name||' update global indexes';
19 dbms_output.put_line(l_drop_sql);
20 execute immediate l_drop_sql;
21 end if;
22 end LOOP;
23 execute immediate 'alter table "sch1"."AUDITS" set interval (NUMTOYMINTERVAL(1,''month''))';
24 execute immediate 'alter table "CFCC"."ALERTAUDITS" set interval (NUMTOYMINTERVAL(1,''month''))';
25 end;
26 /
Procedure created.
Please help me with it..
For interval partitions, the column INTERVAL in the data dictionary view USER_TAB_PARTITIONS is set to YES:
SELECT table_name, partition_name, partition_position, INTERVAL, segment_created
FROM user_tab_partitions;
TABLE_NAME PARTITION_NAME PARTITION_POSITION INTERVAL SEGMENT_CREATED
MYTABLE PRE2014 1 NO NO
MYTABLE SYS_P385 2 YES YES
MYTABLE SYS_P401 3 YES YES
MYTABLE SYS_P441 4 YES YES
To find if a table is interval partitioned, whether or not any partitions based on the interval have been created, you can check (DBA)(ALL)(USER)_PART_TABLES.INTERVAL. If it's not NULL this column contains the partitioning interval specified when the table was created or altered to be interval partitioned. If NULL it means that the table isn't interval partitioned.
Related
I want to Design a table like table F and partition it in such a way that a new partition is created by adding a new data assuming it is not in the existing partitions. (partition based on the date column and 1 partition for each day) . I am new in oracle, please help me ,what is the best idea ? How can I write this code .
Table F is :
DATE Amount ID
2015-05-18 1000 1
2015-05-19 2000 2
2015-05-20 3000 3
2015-05-21 4000 4
2015-05-21 5000 5
2015-05-21 3000 6
2015-05-22 2002 7
You can create several different partitions on a date column ie ( daily, weekly, monthly, quarterly or yearly) and include a local or global index on the column you need to decide what fits your needs
Below is an example of a weekly PARTITION with a global index. The PARTITIONs will be automatically added with a system generated name
when a new date is inserted into the table.
/* weekly PARTITION */
CREATE TABLE t1 (
seq_num NUMBER GENERATED BY DEFAULT AS IDENTITY (START WITH 1) NOT NULL,
dt DATE)
PARTITION BY RANGE (dt)
INTERVAL ( NUMTODSINTERVAL (7, 'DAY') ) (
PARTITION OLD_DATA VALUES LESS THAN (DATE '2022-04-01')
);
/
INSERT into t1 (dt)
with dt (dt, interv) as (
select date '2022-04-01', numtodsinterval(1,'DAY') from dual
union all
select dt.dt + interv, interv from dt
where dt.dt + interv < date '2022-08-31')
select dt from dt;
/
create index t1_global_ix on T1 (dt);
/
Every time a new partition is created Oracle generates a system name, which is quite cryptic
Here is a list of the PARTITION names, which Oracle generated when I loaded the data above
SELECT PARTITION_NAME
FROM USER_TAB_PARTITIONS
WHERE TABLE_NAME = 'T1'
PARTITION_NAME
OLD_DATA
SYS_P458773
SYS_P458774
SYS_P458775
SYS_P458776
SYS_P458777
SYS_P458778
SYS_P458779
SYS_P458780
SYS_P458781
SYS_P458782
SYS_P458783
SYS_P458784
SYS_P458785
SYS_P458786
SYS_P458787
SYS_P458788
SYS_P458789
SYS_P458790
SYS_P458791
SYS_P458792
SYS_P458793
SYS_P458794
Although PARTITION management will work with system GENERATED PARTITION names, I use the procedure below to rename them to something more meaningful.
Let's create and run the procedure and take a look at the names again. As you can see, since we are working with weekly partitions the name is P_ for partittion YYYY 4 digit year the PARTITION is in, W for Week of the year, and ## for the week number within the year.
I would suggest using the scheduler to run this process at least once a day. You can run it as many times as you want as it will not cause any harm.
CREATE OR REPLACE PROCEDURE MaintainPartitions IS EXPRESSION_IS_OF_WRONG_TYPE EXCEPTION;
PRAGMA EXCEPTION_INIT(EXPRESSION_IS_OF_WRONG_TYPE, -6550);
CURSOR PartTables IS
SELECT TABLE_NAME, INTERVAL
FROM USER_PART_TABLES
WHERE PARTITIONING_TYPE = 'RANGE'
ORDER BY TABLE_NAME;
CURSOR TabParts(aTableName VARCHAR2) IS
SELECT PARTITION_NAME, HIGH_VALUE
FROM USER_TAB_PARTITIONS
WHERE regexp_like(partition_name,'^SYS_P[[:digit:]]{1,10}') AND
TABLE_NAME = aTableName AND
table_name not like 'BIN$%'
and interval is not null
ORDER BY PARTITION_POSITION;
ym INTERVAL YEAR TO MONTH;
ds INTERVAL DAY TO SECOND;
newPartName VARCHAR2(30);
PERIOD TIMESTAMP;
BEGIN
FOR aTab IN PartTables LOOP
BEGIN
EXECUTE IMMEDIATE 'BEGIN :ret := '||aTab.INTERVAL||'; END;' USING OUT ds;
ym := NULL;
EXCEPTION
WHEN EXPRESSION_IS_OF_WRONG_TYPE THEN
EXECUTE IMMEDIATE 'BEGIN :ret := '||aTab.INTERVAL||'; END;' USING OUT ym;
ds := NULL;
END;
FOR aPart IN TabParts(aTab.TABLE_NAME) LOOP
EXECUTE IMMEDIATE 'BEGIN :ret := '||aPart.HIGH_VALUE||'; END;' USING OUT PERIOD;
IF ds IS NOT NULL THEN
IF ds >= INTERVAL '7' DAY THEN
-- Weekly partition
EXECUTE IMMEDIATE 'BEGIN :ret := TO_CHAR('||aPart.HIGH_VALUE||' - :int, :fmt); END;' USING OUT newPartName, INTERVAL '1' DAY, '"P_"IYYY"W"IW';
ELSE
-- Daily partition
EXECUTE IMMEDIATE 'BEGIN :ret := TO_CHAR('||aPart.HIGH_VALUE||' - :int, :fmt); END;' USING OUT newPartName, INTERVAL '1' DAY, '"P_"YYYYMMDD';
END IF;
ELSE
IF ym = INTERVAL '3' MONTH THEN
-- Quarterly partition
EXECUTE IMMEDIATE 'BEGIN :ret := TO_CHAR('||aPart.HIGH_VALUE||' - :int, :fmt); END;' USING OUT newPartName, INTERVAL '1' DAY, '"P_"YYYY"Q"Q';
ELSE
-- Monthly partition
EXECUTE IMMEDIATE 'BEGIN :ret := TO_CHAR('||aPart.HIGH_VALUE||' - :int, :fmt); END;' USING OUT newPartName, INTERVAL '1' DAY, '"P_"YYYYMM';
END IF;
END IF;
IF newPartName <> aPart.PARTITION_NAME THEN
EXECUTE IMMEDIATE 'ALTER TABLE '||aTab.TABLE_NAME||' RENAME PARTITION '||aPart.PARTITION_NAME||' TO '||newPartName;
END IF;
END LOOP;
END LOOP;
END MaintainPartitions;
/
EXEC MaintainPartitions
SELECT PARTITION_NAME
FROM USER_TAB_PARTITIONS
WHERE TABLE_NAME = 'T1'
PARTITION_NAME
OLD_DATA
P_2022W14
P_2022W15
P_2022W16
P_2022W17
P_2022W18
P_2022W19
P_2022W20
P_2022W21
P_2022W22
P_2022W23
P_2022W24
P_2022W25
P_2022W26
P_2022W27
P_2022W28
P_2022W29
P_2022W30
P_2022W31
P_2022W32
P_2022W33
P_2022W34
SELECT COUNT(*) FROM USER_TAB_PARTITIONS
COUNT(*)
31
Next step is setting up your RETENTION table. There should be an entry for each interval range PARTITION.
The RETENTION value is for you to decide. In my example, I chose 30 days fir table T1. This means, when the high value for a PARTITION is greater than 30 days its eligible to be dropped. So chose wisely when setting up these values.
Note: I listed the names of other tables to show how each table has its own value.
CREATE TABLE PARTITION_RETENTION (
seq_num NUMBER GENERATED BY DEFAULT AS IDENTITY (START WITH 1) NOT NULL,
TABLE_NAME VARCHAR2(30),
RETENTION INTERVAL DAY(3) TO SECOND(0),
CONSTRAINT
partition_retention_pk primary key (table_name),
CONSTRAINT CHK_NON_ZERO_DAYS CHECK (
RETENTION > INTERVAL '0' DAY
),
CONSTRAINT CHK_WHOLE_DAYS CHECK (
EXTRACT(HOUR FROM RETENTION) = 0
AND EXTRACT(MINUTE FROM RETENTION) = 0
AND EXTRACT(SECOND FROM RETENTION) = 0
)
);
insert into PARTITION_RETENTION (TABLE_NAME, RETENTION)
select 'T0', interval '10' day from dual union all
select 'T1', interval '30' day from dual union all
select 'T2', interval '15' day from dual union all
select 'T3', interval '30' day from dual union all
select 'T4', 15 * interval '1' day from dual union all
select 'T5', 5 * interval '1 00:00:00' day to second from dual;
Below are 3 procedures that need to be created.
The ddl procedure is a wrapper, which shows you what is being processed and how long it takes.
The rebuild_index procedure is obvious it rebuilds any invalid indexes. As I mentioned above if you are using a global index and a PARTITION is dropped then the index needs to be rebuilt. I hardcoded parallel 4 in this example but if you have plenty if CPU power you may want to increase the number to fit your needs.
In addition, there are other ways indexes can be marked unusable so you may want to consider scheduling that task.
Lastly, is the anonymous block. Which actually drops the PARTITIONS for, which the retention PERIOD has passed. This needs to be scheduled once a day!!
If you look carefully at the anonymous block the last step is a call to the rebuild index procedure. So if an index is unusable it will be rebuilt.
Now let's run the process and see what happens.
CREATE OR REPLACE PROCEDURE ddl(p_cmd varchar2)
authid current_user
is
t1 pls_integer;
BEGIN
t1 := dbms_utility.get_time;
dbms_output.put_line(p_cmd);
execute immediate p_cmd;
dbms_output.put_line((dbms_utility.get_time - t1)/100 || ' seconds');
END;
/
CREATE OR REPLACE PROCEDURE rebuild_index
authid current_user
is
BEGIN
for i in (
select index_owner, index_name, partition_name, 'partition' ddl_type
from all_ind_partitions
where status = 'UNUSABLE'
union all
select owner, index_name, null, null
from all_indexes
where status = 'UNUSABLE'
)
loop
if i.ddl_type is null then
ddl('alter index '||i.index_owner||'.'||i.index_name||' rebuild parallel 4 online');
else
ddl('alter index '||i.index_owner||'.'||i.index_name||' modify '||i.ddl_type||' '||i.partition_name||' rebuild parallel 4 online');
end if;
end loop;
END;
/
DECLARE
CANNOT_DROP_LAST_PARTITION EXCEPTION;
PRAGMA EXCEPTION_INIT(CANNOT_DROP_LAST_PARTITION, -14758);
CANNOT_DROP_ONLY_ONE_PARTITION EXCEPTION;
PRAGMA EXCEPTION_INIT(CANNOT_DROP_ONLY_ONE_PARTITION, -14083);
ts TIMESTAMP;
CURSOR TablePartitions IS
SELECT TABLE_NAME, PARTITION_NAME, p.HIGH_VALUE, t.INTERVAL, RETENTION, DATA_TYPE
FROM USER_PART_TABLES t
JOIN USER_TAB_PARTITIONS p USING (TABLE_NAME)
JOIN USER_PART_KEY_COLUMNS pk ON pk.NAME = TABLE_NAME
JOIN USER_TAB_COLS tc USING (TABLE_NAME, COLUMN_NAME)
JOIN PARTITION_RETENTION r USING (TABLE_NAME)
WHERE pk.object_type = 'TABLE' AND
t.partitioning_type = 'RANGE' AND
REGEXP_LIKE (tc.data_type, '^DATE$|^TIMESTAMP.*');
BEGIN
FOR aPart IN TablePartitions LOOP
EXECUTE IMMEDIATE 'BEGIN :ret := '||aPart.HIGH_VALUE||'; END;' USING OUT ts;
IF ts < SYSTIMESTAMP - aPart.RETENTION THEN
BEGIN
ddl('alter table '||aPart.TABLE_NAME||' drop partition '||aPart.partition_name);
EXCEPTION
WHEN CANNOT_DROP_ONLY_ONE_PARTITION THEN
DBMS_OUTPUT.PUT_LINE('Cant drop the only partition '||aPart.PARTITION_NAME ||' from table '||aPart.TABLE_NAME);
ddl('ALTER TABLE '||aPart.TABLE_NAME||' TRUNCATE PARTITION '||aPart.PARTITION_NAME);
WHEN CANNOT_DROP_LAST_PARTITION THEN
BEGIN
DBMS_OUTPUT.PUT_LINE('Drop last partition '||aPart.PARTITION_NAME ||' from table '||aPart.TABLE_NAME);
EXECUTE IMMEDIATE 'ALTER TABLE '||aPart.TABLE_NAME||' SET INTERVAL ()';
ddl('alter table '||aPart.TABLE_NAME||' drop partition '||aPart.partition_name);
EXECUTE IMMEDIATE 'ALTER TABLE '||aPart.TABLE_NAME||' SET INTERVAL( '||aPart.INTERVAL||' )';
EXCEPTION
WHEN CANNOT_DROP_ONLY_ONE_PARTITION THEN
-- Depending on the order the "last" partition can be also the "only" partition at the same time
EXECUTE IMMEDIATE 'ALTER TABLE '||aPart.TABLE_NAME||' SET INTERVAL( '||aPart.INTERVAL||' )';
DBMS_OUTPUT.PUT_LINE('Cant drop the only partition '||aPart.PARTITION_NAME ||' from table '||aPart.TABLE_NAME);
ddl('ALTER TABLE '||aPart.TABLE_NAME||' TRUNCATE PARTITION '||aPart.PARTITION_NAME);
END;
END;
END IF;
END LOOP;
rebuild_index();
END;
alter table T1 drop partition OLD_DATA
.02 seconds
alter table T1 drop partition P_2022W14
.01 seconds
alter table T1 drop partition P_2022W15
.02 seconds
alter table T1 drop partition P_2022W16
.01 seconds
alter table T1 drop partition P_2022W17
.02 seconds
alter table T1 drop partition P_2022W18
.01 seconds
alter table T1 drop partition P_2022W19
.02 seconds
alter table T1 drop partition P_2022W20
.01 seconds
alter table T1 drop partition P_2022W21
.01 seconds
alter table T1 drop partition P_2022W22
.02 seconds
alter table T1 drop partition P_2022W23
.01 seconds
alter table T1 drop partition P_2022W24
.01 seconds
alter table T1 drop partition P_2022W25
.01 seconds
alter table T1 drop partition P_2022W26
.01 seconds
alter table T1 drop partition P_2022W27
.02 seconds
alter index SQL_WUKYPRGVPTOUVLCAEKUDCRCQI.T1_GLOBAL_IX rebuild parallel 4 online
.1 seconds
…
…
…
alter index SQL_WUKYPRGVPTOUVLCAEKUDCRCQI.T1_GLOBAL_IX rebuild parallel 4 online
.1 seconds
SELECT count(*) from USER_TAB_PARTITIONS
Where
table_name not like 'BIN$%'
8
SELECT PARTITION_NAME
FROM USER_TAB_PARTITIONS
WHERE TABLE_NAME = 'T1'
AND
table_name not like 'BIN$%'
P_2022W28
P_2022W29
P_2022W30
P_2022W31
P_2022W32
P_2022W33
P_2022W34
P_2022W35
I have an Oracle database that has 20 very large tables, each with hundreds of partitions. I can compress a table but it takes over 2 hours. This would mean over 40 hours to complete all 20 tables. I would like to run the partition compression simultaneously (1 per table). Because the partitions are added daily I need a utility to generate the "alter table ..." syntax at the time of the run. So far, all I can think of is to create a SQL for each of the 20 tables and their partitions, then run them in 20 SQLPlus sessions.
Is there a better, more automated way to do this?
You could submit several jobs, which will - in turn - run your code simultaneously. Here's an example:
Test tables - I want to modify ID's datatype to VARCHAR2(10)
SQL> create table t1 (id varchar2(2));
Table created.
SQL> create table t2 (id varchar2(2));
Table created.
SQL> create table t3 (id varchar2(2));
Table created.
A procedure which will utilize EXECUTE IMMEDIATE and is called from DBMS_JOB (see below):
SQL> create or replace procedure p_exe (par_what in varchar2) is
2 begin
3 execute immediate par_what;
4 end;
5 /
Procedure created.
Create jobs which will run the ALTER TABLE simultaneously
SQL> declare
2 l_str varchar2(200);
3 l_job number;
4 begin
5 for cur_r in (select 't1' table_name from dual union all
6 select 't2' from dual union all
7 select 't3' from dual)
8 loop
9 l_str := 'alter table ' || cur_r.table_name || ' modify id varchar2(10)';
10 dbms_output.put_line(l_str);
11 dbms_job.submit(l_job,
12 'p_exe(' || chr(39) || l_str || chr(39) ||');',
13 sysdate
14 );
15 commit;
16 end loop;
17 end;
18 /
PL/SQL procedure successfully completed.
Jobs are now running; in a few moments (in my case, as it is a simple one - you'd check that somewhat later), check what's being done:
SQL> desc t1;
Name Null? Type
----------------------- -------- ----------------
ID VARCHAR2(10)
SQL> desc t3;
Name Null? Type
----------------------- -------- ----------------
ID VARCHAR2(10)
SQL> desc t3;
Name Null? Type
----------------------- -------- ----------------
ID VARCHAR2(10)
SQL>
I have a table based on daily partitions.
I can drop a paritition using the below query
ALTER TABLE MY_TABLE DROP PARTITION FOR(TO_DATE('19-DEC-2017','dd-MON-yyyy'))
How can I drop all the partitions (multiple partitions) before 15 days?
You can use PL/SQL like this.
DECLARE
CANNOT_DROP_LAST_PARTITION EXCEPTION;
PRAGMA EXCEPTION_INIT(CANNOT_DROP_LAST_PARTITION, -14758);
ts TIMESTAMP;
BEGIN
FOR aPart IN (SELECT PARTITION_NAME, HIGH_VALUE FROM USER_TAB_PARTITIONS WHERE TABLE_NAME = 'MY_TABLE') LOOP
EXECUTE IMMEDIATE 'BEGIN :ret := '||aPart.HIGH_VALUE||'; END;' USING OUT ts;
IF ts < SYSTIMESTAMP - INTERVAL '15' DAY THEN
BEGIN
EXECUTE IMMEDIATE 'ALTER TABLE MY_TABLE DROP PARTITION '||aPart.PARTITION_NAME|| ' UPDATE GLOBAL INDEXES';
EXCEPTION
WHEN CANNOT_DROP_LAST_PARTITION THEN
EXECUTE IMMEDIATE 'ALTER TABLE MY_TABLE SET INTERVAL ()';
EXECUTE IMMEDIATE 'ALTER TABLE MY_TABLE DROP PARTITION '||aPart.PARTITION_NAME;
EXECUTE IMMEDIATE 'ALTER TABLE MY_TABLE SET INTERVAL( INTERVAL ''1'' DAY )';
END;
END IF;
END LOOP;
END;
For interval partitioned tables (that you probably use based on the exception ORA-14758) you may profit from using the partition_extended_name syntax.
You need not know the partition name, you reference the partition with a DATE, e.g.
alter table INT_PART drop partition for (DATE'2018-09-01')
So to drop your last 15 partitions starting with the current day this loop is to be performed:
declare
v_sql VARCHAR2(4000);
begin
for cur in (select
trunc(sysdate,'MM') - numtodsinterval(rownum - 1, 'day') my_month
from dual connect by level <= 15)
loop
v_sql := q'[alter table INT_PART drop partition for (DATE']'||
to_char(cur.my_month,'YYYY-MM-DD')||q'[')]';
execute immediate v_sql;
end loop;
end;
/
You must use execute immediateas the DATEin the ALTER TABLE statement must by static.
Following statements are generated and executed:
alter table INT_PART drop partition for (DATE'2018-09-01')
alter table INT_PART drop partition for (DATE'2018-08-31')
....
alter table INT_PART drop partition for (DATE'2018-08-19')
alter table INT_PART drop partition for (DATE'2018-08-18')
Additional to the exception ORA-14758 (that I ignore - see the note below) you should handle the exception
ORA-02149: Specified partition does not exist
dependent on you business this should be probably ignored - for this day no partition exists (and you will never reference this day using the partition dictionary metadata).
Note to workaround the ORA-14758 Last partition in the range section cannot be dropped exception you may use this little trick.
I create a dummy partition (without an extent) called P_MINVALUE that plays the role of the interval start in the far past and it will therefore never be dropped.
CREATE TABLE int_part
(
transaction_date TIMESTAMP not null,
vc_pad VARCHAR2(100)
)
SEGMENT CREATION DEFERRED
PARTITION BY RANGE (transaction_date) INTERVAL (NUMTODSINTERVAL(1,'DAY'))
(
PARTITION P_MINVALUE VALUES LESS THAN (TO_DATE('2000-01-01', 'YYYY-MM-DD') )
);
I have one table and I need to create one dummy table with same column names and data but with different datatypes for some of the columns.
For example: Table-1 has two columns C1 (varchar2) and C2(date).
I need to create a dummy table called Table-2 with columns C1 (varchar2) and C2(varchar2).
Please suggest the way to do it in oracle.
The best way to do this is to duplicate the table with create as select, without the data, for example -
create table Table-2 as select * from Table-1 where 1=0;
And then alter the datatypes of the required columns manually like so -
alter table Table-2 modify (C2 varchar2);
After the column was altered you can push the data from Table-1 into Table-2, using proper conversions. in your example -
insert into Table-2 select C1, to_char(C2,'dd-mm-yyyy') from Table-1;
Assuming that all the columns of the starting table can be converted ( implicit conversion) in VARCHAR2, you can do something like the following.
Say you have this table:
SQL> create table table1 (
2 date_field date,
3 varchar_field varchar2(1000),
4 number_field number
5 );
Table created.
SQL> insert into table1 values (sysdate, 'some text', 999);
1 row created.
SQL> commit;
Commit complete.
You can build a dynamis SQL that creates another table and copies the data from one table to another, using implicit type conversion:
SQL> declare
2 stm varchar2(32767);
3 begin
4 select 'create table table2( ' ||
5 listagg(column_name, ' varchar2(4000), ') within group (order by column_name) ||
6 ' varchar2(4000) )'
7 into stm
8 from user_tab_columns
9 where table_name = 'TABLE1';
10 --
11 execute immediate stm;
12 --
13 select 'insert into table2( ' ||
14 listagg(column_name, ', ') within group (order by column_name) ||
15 ' ) select ' ||
16 listagg(column_name, ', ') within group (order by column_name) ||
17 ' from table1'
18 into stm
19 from user_tab_columns
20 where table_name = 'TABLE1';
21 execute immediate stm;
22 end;
23 /
PL/SQL procedure successfully completed.
SQL> select * from table2;
DATE_FIELD NUMBER_FIELD VARCHAR_FIELD
--------------- --------------- ---------------
27-APR-16 some text 999
SQL>
I need to create a Oracle tables with random number of columns for load testing. I just want to specify number of columns with type NUMBER, number of columns with type VARCHAR2 etc and the fields should be generated automatically. Also, I will be filling up the tables with random data for which I will be using dbms_random.
How can I achieve this?
"I just want to specify number of
columns with type NUMBER, number of
columns with type VARCHAR2 etc and the
fields should be generated
automatically."
The following procedure does just that. Note that it is rather basic; you might want to make it more sophisticated, for example by varying the length of the varchar2 columns:
SQL> create or replace procedure bld_table
2 ( p_tab_name in varchar2
3 , no_of_num_cols in pls_integer
4 , no_of_var_cols in pls_integer
5 , no_of_date_cols in pls_integer
6 )
7 as
8 begin
9 execute immediate 'create table '||p_tab_name||' ('
10 ||' pk_col number not null'
11 ||', constraint '||p_tab_name||'_pk primary key (pk_col) using index)';
12 << numcols >>
13 for i in 1..no_of_num_cols loop
14 execute immediate 'alter table '||p_tab_name||' add '
15 ||' col_n'||trim(to_char(i))||' number';
16 end loop numcols;
17 << varcols >>
18 for i in 1..no_of_var_cols loop
19 execute immediate 'alter table '||p_tab_name||' add '
20 ||' col_v'||trim(to_char(i))||' varchar2(30)';
21 end loop varcols;
22 << datcols >>
23 for i in 1..no_of_date_cols loop
24 execute immediate 'alter table '||p_tab_name||' add '
25 ||' col_d'||trim(to_char(i))||' date';
26 end loop datcols;
27 end bld_table;
28 /
Procedure created.
SQL>
Here it is in action:
SQL> exec bld_table ('T23', 2, 3, 0)
PL/SQL procedure successfully completed.
SQL> desc t23
Name Null? Type
----------------------------------------- -------- ----------------------------
PK_COL NOT NULL NUMBER
COL_N1 NUMBER
COL_N2 NUMBER
COL_V1 VARCHAR2(30 CHAR)
COL_V2 VARCHAR2(30 CHAR)
COL_V3 VARCHAR2(30 CHAR)
SQL>
We can also use dynamic SQL to populate the table with rows of random data.
SQL> create or replace procedure pop_table
2 ( p_tab_name in varchar2
3 , p_no_of_rows in pls_integer
4 )
5 as
6 stmt varchar2(32767);
7 begin
8 stmt := 'insert into '||p_tab_name
9 || ' select rownum ';
10 for r in ( select column_name
11 , data_type
12 , data_length
13 from user_tab_columns
14 where table_name = p_tab_name
15 and column_name != 'PK_COL' )
16 loop
17 case r.data_type
18 when 'VARCHAR2' then
19 stmt := stmt ||', dbms_random.string(''a'', '||r.data_length||')';
20 when 'NUMBER' then
21 stmt := stmt ||', dbms_random.value(0, 1000)';
22 when 'DATE' then
23 stmt := stmt ||', sysdate + dbms_random.value(-1000, 0)';
24 end case;
25 end loop;
26 stmt := stmt || ' from dual connect by level <= '||p_no_of_rows;
27 execute immediate stmt;
28 end pop_table;
29 /
Procedure created.
SQL>
Note that the primary key is populated with the ROWNUM so it will most likely fail if the table already contains rows.
SQL> exec pop_table('T23', 4)
PL/SQL procedure successfully completed.
SQL> select * from t23
2 /
PK_COL COL_N1 COL_N2 COL_V1 COL_V2 COL_V3
---------- ---------- ---------- ------------------------------ ----------------------------- ------------------------------
1 913.797432 934.265814 NUtxjLoRQMCTLNMPKVGbTZwJeYaqnXTkCcWu WFRSHjXdLfpgVYOjzrGrtUoX jIBSoYOhSdhRFeEeFlpAxoanPabvwK
2 346.879815 104.800387 NTkvIlKeJWybCTNEdvsqJOKyidNkjgngwRNN PPIOInbzInrsVTmFYcDvwygr RyKFoMoSiWTmjTqRBCqDxApIIrctPu
3 93.1220275 649.335267 NTUxzPRrKKfFncWaeuzuyWzapmzEGtAwpnjj jHILMWJlcMjnlboOQEIDFTBG JRozyOpWkfmrQJfbiiNaOnSXxIzuHk
4 806.709357 857.489387 ZwLLkyINrVeCkUpznVdTHTdHZnuFzfPJbxCB HnoaErdzIHXlddOPETzzkFQk dXWTTgDsIeasNHSPbAsDRIUEyPILDT
4 rows selected.
SQL>
Again, there are all sorts of ways to improve the sophistication of the data.
As an aside, using these sorts of data pools for load testing is not always a good idea. Performance problems are often caused by skews in the distribution of data values which you just aren't going to get with DBMS_RANDOM. This is particularly true of some date columns - e.g. START_DATE - which would tend to be clustered together in real life but the above procedure will not generate that pattern. Similarly maxing out the varchar2 columns will lead to tables which take up more storage than they wlll under real-life usage.
In short, randomly generated data is better than nothing but we need to understand its weaknesses.
Two approaches
1) Write code to generate text files containing the CREATE TABLE commands that you need to run and populate your tables, then execute these using SQL*Plus.
2) Use Dynamic SQL embedded inside PL/SQL -
PROCEDURE create_random_table
(pTableName IN VARCHAR2,
pNumberOfColumns IN INTEGER)
IS
PRAGMA AUTONOMOUS_TRANSACTION;
lCommand VARCHAR2(32000);
BEGIN
lCommand :=
'CREATE TABLE '||pTableName||'(';
FOR i IN 1..pNumberOfColumns LOOP
append your column definition here
END LOOP;
lCommand := lCommand||';';
--
EXECUTE IMMEDIATE lCommand;
END;
You could also use 'CREATE TABLE AS SELECT' to populate your table at the same time (see other answer).
This should give you a good starting point - there isn't anything in the system that will do what you want without writing code.
You may generate such table by yourself.
Create table with required datatypes:
Create Table RandomTable
AS
Select dbms_random.string('A', 1) CharField,
dbms_random.string('a', 20) VarCharField,
TRUNC(dbms_random.value(0, 35000)) IntField,
dbms_random.value(0, 35000) NumberField,
Level SequenceField,
sysdate + dbms_random.value(-3500, 3500) DateField
from dual connect by level < 1000
(You can change 1000 to required rows numbers, and add required data types)
After that you can create or populate tables with random data from RandomTable
Create Table TestTable1
AS
SELECT CharField as a, NumberField as b
from RandomTable
INSERT INTO TestTable2(DateFrom, Quantity)
SELECT DateField, IntField
from RandomTable
Where SequenceField <= 500