Partitioning - Switch Partition Key On Existing Table?
Jan 23, 2011
I recently started working with legacy code and noticed that some huge tables (5 years worth of data, don't have more details on me right now but can post later if needed) are partitioned based on time sequence number column while majority of queries are done based on time (different column). Queries performance is degrading and I'd like to try to modify partitioning and run some tests to evaluate performance improvement.
My only concern is with so much live data I have to come up with solution on how to switch partitioning with the least impact on applications running 24 x 7. Something you have done in the same situation and it worked?
DECLARE v_name VARCHAR2(256); BEGIN SELECT sys_context('userenv', 'current_user') INTO v_name FROM dual; DBMS_REDEFINITION.CAN_REDEF_TABLE(v_name, 'SO33070_ORIGINAL', dbms_redefinition.CONS_USE_ROWID); END;
Success
3. Creating a duplicate table
CREATE TABLE SO33070_NEW ( SERIAL_ID NUMBER(15,0), INSERTED_TIME DATE DEFAULT SYSDATE ) PARTITION BY RANGE ("INSERTED_TIME") INTERVAL (NUMTODSINTERVAL(1,'DAY')) ( PARTITION "p1_1" VALUES LESS THAN (TO_DATE(' 2012-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) )
We have a transaction table and has 30 million rows. The table is not partitioned till date. We need to create partition on this table. We had an idea of moving this data to a temporary table and create partition[range]on the original table and move the data back.
I need to partition a existing table based on varchar2 field (which is actaully date value but storing as character in the table). Using below statement for creating table, but getting error.
I am trying to create a partitioned table so that a number (which date converted to number ) partition is created on inserting a new row for release_date column.
note that release_date column is having number data type (as per design) and people want to create an interval based partition on this.
They want data type NOT to be altered.
create table product( prod_id number, prod_code varchar2(3), release_date number) partition by range(release_date) interval(NUMTOYMINTERVAL (1,'MONTH')) (partition p0 values less than (20120101))
I have created an Interval Partition Table as show below, Is their any way, i can drop the partition dynamically when i truncate the table as oracle creates them with system generated name? Instead Alter table drop partition !
Insert Script : ------------------------------------------------------------------------------------------------------------------------------------------------ INSERT INTO TBL_EMP_SALES VALUES (1001,'A',50,SYSDATE); INSERT INTO TBL_EMP_SALES VALUES (1002,'B',100,SYSDATE+1); INSERT INTO TBL_EMP_SALES VALUES (1003,'C',80,SYSDATE+2);
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Partitions Created : ------------------------------------------------------------------------------------------------------------------------------------------------- select segment_name,partition_name,bytes from user_segments where segment_name = 'TBL_EMP_SALES'; segment_name partition_name bytes
I have problem to transfer data in non partitioning table to partitioning table.
I have non partitioning table and i create new table partitioning that have same column and type like in non partitioning. So how can i transfer data from table in non partitioning to table in partitioning?
I have a partitioned table in which at the first level it is been partitioned based on date column(C1) and within in each partition it is again sub-partitioned based on a column(C1) which is a numeric value now at first level(C1 column level) there are 6 partitions and in the last partition i want to add another partition how can i do that.
table was defined as below & indexes are also created on name /dept columns, data is also available :
create table test ( name varchar2(10), version NUMBER(12), dept varchar2(10) [code].....
Now the requirement is that the parition keys has to be changed to 'dept' from the existing 'version' . How to accomplish this without any implication on the indexes and other constraints.
I think that performance better partition table than non-partition table. How to assure partition table is better than non-partition table at SELECT operation?
I have compare a specific query EXPLAIN PLAN at partition table and non-partition table. both tables data is same. Is it true way or not?
I have a table that partitioned into six partitions. each partitions placed in different table space and every two table space placed it on a different hardisk
when I will do query select with the non-partition keys condition, how the search process ? whether the sequence (scan sequentially from partition 1 to partition 6) or partition in a hardisk is accessed at the same time with other partition in other hardisk. ( in the image, partition 1,4 accessed at the same time with partition 2,5 and 3,6)
Can i alter the table to create partition on non partition table, i have tried and could not create it. Do we have some other means to do it as this is the live table and cannot drop them else will lose the data.
Can I add range sub partition to a hash partition table. Example like this.
CREATE TABLE test ( test_id VARCHAR2(10 ) , test_TYPE VARCHAR2(5) , CREATE_DATE date ) partition by hash (test_id, test_type) Partitions 3 SUBPARTITION BY RANGE (CREATE_DATE);
When Tried, I am getting syntax error as invalid option.
When I am trying to insert record from tbl_mittal into tbl_temp table. I am facing "ORA-14400: inserted partition key does not map to any partition" error
SQL> insert into tbl_temp select * from tbl_mittal; insert into tbl_temp select * from tbl_mittal * ERROR at line 1: ORA-14400: inserted partition key does not map to any partition
AS tbl_mittal is having hugh number of records so I am providing only few rows from tbl_mittal table as test data.
I partitioned a source table of around 100 million rows (62GB) in DEV server. The target database was created new. It was range partioned on a date column as follows:
PARTITION BY RANGE (ENTRY_DATE_TIME) ( PARTITION ppre2012 values less than (TO_DATE('01/01/2012','DD/MM/YYYY')) TABLESPACE WST_LRG_D, PARTITION p2012 values less than (TO_DATE('01/01/2013','DD/MM/YYYY')) TABLESPACE WST_LRG_D, PARTITION p2013 values less than (TO_DATE('01/01/2014','DD/MM/YYYY')) TABLESPACE WST_LRG_D, PARTITION p2014 values less than (MAXVALUE) TABLESPACE WST_LRG_D )
That is yearly basis. Anything before 2012 went to ppre2012, then p2012, p2013 and so forth. There is 20 million rows in p2012. and around 75 million rows in ppre2012. We needed both the source (un-partitioned) and target (partitioned) tables in DEv for comparision. The queries are normally on the current year partition. Just to state taht I am a developer and don't have full visibility to the production instance.
Now that our tests are complete, we would like to promote this in production. Obviously in production we would not not need both source and target tables. In all probability this will be performed over a weekend window. Therefore I would like to suggest the following .
1) use expdp to export source table 2) drop the source table 3) create a new source table "partitioned" with no indexes 4) use impdp to get data back into table 5) create global index (it is a unique index to enforce uniquness) and the rest of indexes as local 6) perform dbms_stats.gather_table_stats(user,'SOURCE', cascade=>true). This takes around 2 hours in dev
My point is that whether importing 100 million rows will not cause issues with undo segments. Can we import data say first to the current partition p2012 (20 million rows) first.
How to find the size pf a partition in a partition table?I guess we need to query views like dba_tab_partitions but I am not very sure. will running dbms_stats.gather_table_stats('schema_name,'table_name,'partition_name')
I have a big table in which we load about 37M recrods. We have informatica ETL which Loads the data in bulk Mode and creats index after completion. The data load takes about 1Hr and Index Creation takes about 1/2 hr. In total it takes about 90 to 95 Mnts.
Now I thought if Partition and Load paralley, It will improve perfromance. We did 4 partition and and each Partition about 9M records. The data load in Bulk mode is completing in 25 Mnts. Again When I am creating index over it, It is taking about 40 Mnts. and in Total Load time is 65 Mnts.
Is there way I can better performance to complete the load in 1/2 hr ?
At moment we use range-hash partitioning of a large dimension table (dimension model warehouse) table with 2 levels - range partitioned on columns only available at bottom level of hierarchy - date and issue_id.
Result is a partition with null value - assume would get a null partition in large fact table if was partitioned with reference to the large dimension.Large fact table similarly partitioned date range-hash local bitmap indexes
Suggested to use would get automatic partition-wise joins if used reference partitioningWould have thought would get that with range-hash on both dimension.
Database Version : DB : Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit ProductionOS : HP-UX nduhi18 B.11.31 U ia64 1022072414 unlimited-user licenseAPP : SAP - ERP I have to RANGE partition on UPDATED_ON or PROFILE either one table which is having below
structure : Name Null? Type -------------------- -------- -------------------------------- MANDT NOT NULL VARCHAR2(9) MR_ID NOT NULL VARCHAR2(60) PROFILE NOT NULL VARCHAR2(54) REGISTER_ID NOT NULL VARCHAR2(30) INTERVAL_DATE NOT NULL VARCHAR2(24) AGGR_CONSUMPTION NOT NULL NUMBER(21,6) MDM_VERS_NO NOT NULL VARCHAR2(9) MDP_UPDATE_DATE NOT NULL VARCHAR2(24) MDP_UPDATE_TIME NOT NULL VARCHAR2(18) NMI_CONFIG NOT NULL VARCHAR2(120) NMI_CONFIG_FLAG NOT NULL VARCHAR2(3) MDM_DATA_STRM_ID NOT NULL VARCHAR2(6) NSRD NOT NULL VARCHAR2
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As per my knowledge, RANGE is better suited for DATE or NUMBER. and INTERVAL partition is possible on DATE or NUMBEr . Column PROFILEIts is of VARCHAR2 datatype. I know still I can partition as Oracle internally convert varchar2 to number while inserting data. But INTERVAL is not possible. How to RANGE partition on PROFILE ? Column CREATED_ON :It is of NUMBER with decimal
I think that performance better partition table than non-partition table. How to assure partition table is better than non-partition table at SELECT operation?
I have compare a specific query EXPLAIN PLAN at partition table and non-partition table. both tables data is same. Is it true way or not?
I have to convert some existing materialized views (fast refresh) to partition materialized views.
Database version is oracle 10.1.0.4. I have decided to use on prebuilt table option to do the partitioning as it minimizes the time to transfer from the master site.
1) stop replication 1) create interim tables with similar structure as the materialized views 2) transfer all data from the materialized views to the interim tables 4) script out the materialized views structure and add in on prebuilt table option in the scripts 5) drop the materialized views 6) rename the interim tables with the same name as the materialized views 7) run the scripts to create the materialized views with on prebuilt table option 8) refresh the newly created materialized views -> it should take a short time since I am using on prebuilt table option
But I am facing one major issue. That is if I drop the materialized views, the materialized view logs of the master tables are purged. When the materialized views are refreshed fast, there are some data missing. the data that are purged out when the materialized view are dropped.
Do you happen to know other ways that existing materialized views can be converted to partitioned materialized views? Do you have any workaround to prevent the materialized view logs from being purged?
I am creating a table from another existing table in another schema. The existing table contains data. When I am using the query- create table m _voucher as select * from ipm.m_voucher,I am getting the whole data of m_voucher but I want empty m_voucher table, so what will be the query to get the empty m_voucher table?
