Ways for improving the Table performance which holds million of records for oracle. Currently we have partitioning and indexing but it doesn't seem to work.
trying to update a column in a table which has 3 columns of 16million rows from column in another table which has 1million rows, there is no relationship between the 2 tables.
Table A has 3 columns of 16million rows, the first two columns have 16million ID numbers, the 3rd colunm is currently NULL.
Table B has 1million Numbers, i need to somehow update column 3 in table A using the numbers in table B, it doesnt how many times each of the 1 million numbers are used but i dont want it to just update every row to the same value.
As per Article mentioned in Oracle Base,I have converted non-partitioned table (1 million data) into range-partition table,but,I don't see performance improvement in explain .
We have two tables, TableA and TableB that contain list of accounts and balances.The requirement is to compare the balances of accounts in both the tables, and if there is a difference, then record that difference with account number in another table.
Both TableA and TableB contain more than 10 million rows.What is the best way to do this task in PL/SQL? A join on TableA and TableB to know the differences has become very slow due to large volume.
If a table(have a primary key) is empty(after truncate),the sql of dml(insert,update) is very quickly,but if the table have many rows about 10,000,000 rows, the dml is very slowly,why?
I am trying to update columns of Table A with the columns of Table B. Both these tables have 60,000 rows each. I tried this operation using following 2 queries:
Query 1
Update TableA A set (A.col1,A.col2,A.col3)=(select B.col1,B.col2,B.col3 from TableB where A.CODE=B.CODE)
Query 2 Update TableA A set (A.col1,A.col2,A.col3)=(select B.col1,B.col2,B.col3 from TableB where A.CODE=B.CODE) where exists A.code = (select B.code from TableB B where A.code=B.code)
When i execute these two above queries, it keeps executing indefinitely.
Lets take the basic emp table for our Referenece and lets assume that it contains around 60000 Records and all the deptno in that table are Initially 10. Please provide an update statement which would update deptno column of EMP table((based on) order by EMPNO) in for every 120 records incrementing by 1.(DeptNo to be incremented by 1,like 10 ,11 , 12 etc).
First 120 Records deptno should be 10, Next 120 Records deptno should be 11, and so on. . . . . . . For Last 120 records deptno should be updated with 500.
We have to load 10 million rows in a table from another table based on the multiple joins. How much tablespace size we allocate to the table and for performance point of view how much should be the SGA size.
I am facing some challenge while running update query on newly added column in existing table.
Environment Details Oracle 9i, version 9.2.0.6 Os Unix Aix 6.1
No of records in table : 12572770
Below are the step i followed.
1. In table testtablename, I have added new column COLUMNNAME29 with datatype VARCHAR2(8). 2. After adding the new column, i executed the update query to populate the data form COLUMNNAME1 to COLUMNNAME29. 3. The query is executed using COLUMNNAME24 in where clause, to drive query in index based.
SQL> desc testtablename Name Null? Type ----------------------------------------- -------- ---------------------------- COLUMNNAME1 VARCHAR2(8) COLUMNNAME2 CHAR(1) COLUMNNAME3 CHAR(1) COLUMNNAME4 VARCHAR2(8) COLUMNNAME5 VARCHAR2(11)
[Code]...
Table altered.
SQL> select index_name, column_position, column_name from dba_ind_columns where table_name = 'TESTTABLENAME' order by index_name,column_position;
1. The update query is hanging in database, it's not progressing (In single update, approximately 40000 records will get update) 2. No oracle error thrown in alert log or in session where the query being executed. 3. The event for the query is "db file sequential read". 4. When i update the newly added column COLUMNNAME29 with static value "1", the update completed successfully in few seconds. 5. Then i changed the static value to "1111" and executed the update statement, which result to query hanging in database. 6. I tried to update the existing column(COLUMNNAME1) in table with static value "1111", the update completed successfully.
Below are the queries completed successfully
Update Testtablename Set Columnname29 = '1' Where Columnname24 >= To_Date('01-12-2002 00:00:00', 'DD-MM-YYYY HH24:MI:SS' ) And Columnname24 < To_Date('01-01-2003 00:00:00', 'DD-MM-YYYY HH24:MI:SS')
[Code]...
Below are the queries hanging in database
Update Testtablename
Set Columnname29 = Columnname1 Where Columnname24 >= To_Date('01-12-2002 00:00:00', 'DD-MM-YYYY HH24:MI:SS' ) And Columnname24 < To_Date('01-01-2003 00:00:00', 'DD-MM-YYYY HH24:MI:SS')
Update Testtablename
Set Columnname29 = '1111' Where Columnname24 >= To_Date('01-12-2002 00:00:00', 'DD-MM-YYYY HH24:MI:SS' ) And Columnname24 < To_Date('01-01-2003 00:00:00', 'DD-MM-YYYY HH24:MI:SS')
Below is character set in database
SQL> select * from v$nls_parameters; PARAMETER VALUE ---------------------------------------------------------------- ---------------------------------------------------------------- NLS_LANGUAGE AMERICAN NLS_TERRITORY AMERICA NLS_CURRENCY $ NLS_ISO_CURRENCY AMERICA
Can this be optimized, in dev and Ist we didn't realize since 1000 rows were there, but in PERF since 2 mil rows are there this is taking a long time,
SET SERVEROUTPUT ON DECLARE counter number := 0; CURSOR insertValues IS select roleid, productcode, functioncode, typecode, restrictiontype, value1 from restrictions where actionmode = 'INSERT';
[code]...
can this be done in a single update since Selects /Updates are happening on same table
Updating multiple ROWS with different values using single statement. Requirement is to update one column in a table with the values in the other table.
Say we have 3 tables, CORPORATION,CORPORATE PROFILE and MEMBER.
Each MEMBER has CORPORATE PROFILE which in turn is associated with CORPORATION. Now I need to update MEMBER table with CORPORATION identifier for members who belong to corporations with identifiers say 'ABC' and 'DEF'.
MEMBER table contains column 'CORPIDENTIFIER '. CORPORATEPROFILE table contains MEMBERID and CORPORATIONID,this will associate a member with the corporation. CORPORATION table contains ID and CORPIDENTIFIER.
Using the below query I am getting error,ORA-01427:single-row subquery returns more than one row
UPDATE MEMBER M SET M.CORPIDENTIFIER= (SELECT A.IDENTIFIER FROM CORPORATION A,CORPORATEPROFILE B WHERE B.CORPORATIONID=A.ID AND B.MEMBERID=M.ID AND (A.IDENTIFIER LIKE 'ABC' OR A.IDENTIFIER LIKE 'DEF'))
Sub query in the above query returns multiple rows and hence it is throwing the error.More than one members are associated with Corporations ABC and DEF. Is there any way possible to update all the rows in single query with out iterating the result set of sub query.
I have to do the optimization of a query that has the following characteristics:
- Takes 3 hours to process - Performs the inner join with 30 tables - Produces an output of 280 million records with 450 fields
First of all it is not feasible to make 30 updates (one for each table) to 280 million records.
The best solution that I had found so far was to create 3 temporary tables, where each of them to do the join with 1/3 of the 30 tables, and in the end I make the join between the main table and these three tables temporary.
I know that you will ask (or maybe not) to the query and samples, but it is impossible to create 30 examples.
how to optimize this type of querys that perform the join with multiple tables and produce a large output with (too) many columns.
We have a procedure, which do truncate to some of the tables. Most of the time it finished in short of spam of time. But from last few days, it is taking much longer time.
I am looking at an existing utility which inserts data into configuration tables. The utility is fairly basic, you simply add the UPDATE / INSERT / DELETE sql commands to a .sql file, set up a few params in a .sh script in order to tell it which Database / Schema to run against and away it goes, doing some logging, etc on the way.
Most of the time this is fine. However there is one table that causes big performance problems. This large table holds rating data and it has two large triggers on it. It also gets updated quite a bit with new rating tariffs.
The triggers check that many fields are not null or are certain values... but they also check that dates of the rates do no overlap, etc. So, in short, they do a lot of work. I can see that these are the main performance obstacle. I have no ability to alter or disable these triggers, this is a core table supplied by the vendor and as such I cannot manipulate it.
So looking at the things I can change, what am I left with?... only the way I load the data..
I can consider using SQLloader in order to handle INSERTS or using the APPEND hint in order to perform a direct path insert rather than having individual INSERT statements.
I can try to ensure that my data is sorted along the same lines as the index on the table in order to ensure that I am updating the index nodes in as streamlined way as possible. I can improve performance still more, or even circumnavigate the drag of the triggers?
I'm trying to write a query that counts how many sessions are active during a 1 second time interval, then returns the maximum number of sessions active during any time interval, and all the time intervals that hit that max.
I have column containing three values:-N,E,Y.I want to get results with only E and Y values.Is it it possible to create index which would not look for N values.
So our situation is pretty simple. We have 3 tables.
A, B and C
the model is A->>B->>C
Currently A, B and C are range partitioned on a key created_date however it's typical that only C is every qualfied with created date. There is a foreign key from B -> A and C -> Bhave many queries where the data is identified by state that is indexed currently non partitioned on columns in A ... there are also indexes on the foreign keys that get from C -> B -> A. Again these are non partitioned indexes at this time.
It is typical that we qualifier A on either account or user or both. There are indexes (non partitioned on these) We have a problem with now because many of the queries use leading wildcards ie. account like '%ACCOUNT' etc. This often results in large full table scans. Our solution has been to remove the leading wildcard.
We are wondering how we can benefit from partitioning and or sub partitioning table A. since it's partitioned on created_date but rarely qualified by that. We are also wondering where and how we can benefit from either global partitioned index or local partitioned indexes on tables A. We suspect that the index on the foreign key from C to B could be a local partitioned index.
We have database with multiple fields containing NULL values and in many queries we have NVL function which in turn is suppressing the index usage when in fact it is really essential (selectying very few rows from massive data) instead of creating lot of Function based indexes (NVL) or composite indexes with (nullable_column, constant) I am thinking of settting a default value for most of the fields In that regard I have some queries :
Which approach is better - setting default value for the fields or updating the fields with default value and modyfing inserts to take care of future data? Though altering table and modifing column to set default value looks better considering it will take care of data inserted in the future, it will invalidate the subroutines.I understand in 10g both statement will generate lot of undo (though in 11g, I heard things changed for setting default value of a column) How to take care of all the queries which are using the criteria 'where column1 IS NULL' or 'where column1 IS NOT NULL'. It will be really difficult task to manually change each and every occurrence of such condition even using user_source.
Finally for numeric values say for ID field which starts from 1 onwards 2,3,4 etc, we can set 0 as sensible default so that the performance is not affected.
Is there such precaution for varchar2 field purely from performance point of view?
i am using 11.2.0.3.0 version of oracle. We are planning to move some ~40 tables/indexes to new encrypted tablespace as a part of TDE(transparent data encryption). Currently three tables are having size ~30GB and one having ~800GB other have <2GB in size. And tables/indexes are altogether placed in different tablespaces.
whether i should create as many no of encrypted table spaces as it was before as unencrypted tablespace? or I should create one encrypted tablespace and move all the tables/indexes into that?
I have tried a lot by alternate solutions like rearranging the order of tables in join and moving where conditions before but no success...Its a bottleneck and I could not have indexes on these tables in production...I want to change the approach in subquery
SELECT g.COLUMN1, g.COLUMN2, e.COLUMN3, g.COLUMN4, MIN(e.dat1) KEEP ( DENSE_RANK FIRST ORDER BY date2 Desc) * -1, min(to_char(date3,'dd-mm-yyyy')) [code]....
SELECT department_id FROM (SELECT department_id FROM employees UNION SELECT department_id FROM employees_old ) WHERE department_id=100; [code]....
The index has been created on both depart_id for the two tables. The only difference between the two I observed was the 1 recursive call for the 1st sql.and also, one additional view in the plan.There is a little difference in bytes sent over the network.
There is coulmn called DATA in a table with LONG RAW datatype. we are facing more than 60% chained rows in this table because of this LONG RAW column.
It is very difficult to clean up these chained rows periodically. Since an application using this table is a business critical interms of high availability.Hence, is there any other way in oracle to avoid chained rows permanently in future?
1) I have 5 Exported Dump files. 2) All of those 5 dump files were taken in different time periods. 3) Many of those Dump files are having the same Partition records.
eg:- Dump 1:- 01-06-2010 to 31-11-2010 Dump 2:- 01-09-2010 to 31-12-2010
4) Now i want to import all those partitioning data into a single table, without having any duplication.
