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)
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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')
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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
My local currency is INR, I need to write a query to convert the foreign currency to loacl currency INR.In my case i need to write aSQL for a view.It should not implement through PL/SQL
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.
How can i apply currency format to the select list values queried from database tables. The data is stored in database in number format. The user wants to see 1000 separator commas in the list item values.
i have a table in my PD database which have more than 30,000 records .some records in a column say p_code is not tagged with code like '9876543'while other records are tagged in this column with code such as '19022345678'.
Now i want to update these records with tagging 1902 with each one .
i have to update a single column(x.c) in x table.here the condition is x.a is not null and x.b is not null x.d is null then update x.c=x.b for each row.
I have a scenario where I need to update field in report_input table.It has bind variables in it which will be prompted while running the query.I see that QUERY_VALUE field that need to be updated has length of VARCHAR2(3000).
desc report_input Name Null Type ----------------- -------- -------------- QUERY_NAME NOT NULL VARCHAR2(64) QUERY_VALUE NOT NULL VARCHAR2(3000) [code]....
I want this trigger to automatically update the num_songs_in_album column in the album table whenever rows are inserted or deleted into the Track table.
SQL> CREATE OR REPLACE TRIGGER update_num_songs_in_album 2 BEFORE INSERT OR DELETE ON Track 3 FOR EACH ROW 4 BEGIN 5 IF INSERTING THEN [code]....
ITEMNUM STORELOC lastyear currentyear AM1324 AM1 need sum(quantity) here need sum(quantity) AM1324 AM2 need sum(quantity) here need sum(quantity)
We have to update the last year and current year columns with sum of quantities for each item from matusetrans table based on date at different location in Inventory table.
we had nearly 13,000 records(itemnum's with different location) in inventory table in DB we have to update entire records.
How to write an sql queries to update lastyear and currentyear columns with sum of quantities based on itemnum and location in Inventory table
How the length of column width effects index performance?
For example if i had IOT table emp_iot with columns: (id number, job varchar2(20), time date, plan number)
Table key consist of(id, job, time)
Column JOB has fixed list of distinct values ('ANALYST', 'NIGHT_WORKED', etc...).
What performance increase i could expect if in column "job" i would store not names but concrete numbers identifying job names. For e.g. i would store "1" instead 'ANALYST' and "2" instead 'NIGHT_WORKED'.
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.
Now we are supposed to apply column level TDE to some of our table in database. Now it will be a 'ALTER' on the columns. it involves 4 big tables out of which 3 tables having size ~30GB(one is partitioned table) and another one ~800GB(Not partitioned) Now the concern is, what will be the efficient/safest way to apply TDE on columns, below are the two options with us. (NOTE - We do have downtime window during DB maintenance but looking at the size of the table, i suspect it might take lot.)
1. Directly apply 'ALTER' on the columns. (Note- i was testing on my local, it took 3hrs for a 30GB table to ALTER the column to TDE)
2. Use Table Redefinition for Altering the column. (Creating interim table with column as TDE and then Redefining whole table).
SELECT CURRENTSTEP FROM (SELECT ( WFENTRY.NAME || ',' || CURRENTSTEP.STEP_ID ) AS CURRENTSTEP, (CASE WHEN WFENTRY.NAME IN
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in this query I am concatenating tow columns , I use this query as a sub query in my other queries and filter the results with and CURRENTSTEP = ?
here is how I use it
select sys_audit_id from ( SELECT * FROM (SELECT F.FINDING_NUMBER,
[Code]....
I saw adding this as a subquery with the filter and CURRENTSTEP = ? is slowing my query very much , as this is a derived column i cannot add index then how to improve performance for this subquery ?
We have a table called address and having the address fields and city ,state etc. The table will store huge amount of data .We need to query on the table. I would like to know how can we fasten the query and improve the performance of the query by creating index on these columns...Query is given below . note that the nullable columns can have data
I have an issue in materialized view which has got one of the null able column and query on this column taking approximately 2 mins where as other indexed columns takes less than 10 sec.
Here is the summary
SQL> Select Count (1), Count (VAT_NO) From Mv_customer;
If an index is created on VAT_NO will that improve the performance. What kind of index can be created considering very less number of records has got VAT_NO
I'm trying to collect histograms for column COL_C of table TAB_A(150K records), So an index "BAD_IDX" will *not* be used in a query when the value is not selective.
This is my query:
SELECT COL_A, COL_B , COL_C , COL_D , COL_E , COL_F FROM TAB_A WHERE COL_A = 050 AND COL_B = 13012345 AND COL_C = 0 AND COL_D = 0 AND COL_D >= '07/23/2013 00:00:00' ORDER BY COL_E ASC;
Now, I have index "BAD_IDX" on columns (COL_C, COL_E ).and the distribution of values looks like this:
select COL_C, count(*) FROM TAB_A --very not selective for 0, selective for the rest, also no histogram group by rollup(COL_C) order by 2 desc;
and the result is 20k row long (20k distincts), So I'll post just the top part of it:
Now, the problem with the query was that "COL_B = 13012345" was the most selective predicate, And an index for it did not exist, so the index "BAD_IDX" is used, and is scanning 86k records (all the "0" value records for column COL_C)!
So, I created an index
Create index GOOD_IDX on TAB_A(COL_B) compute statistics;
However, that BAD_IDX index is still being used! I've thought that maybe it's because the lack of histograms for the column COL_C.I've also understood from documentation I've read that the suitable histogram type is TOP FREQUENCY, Because although I have 20k distincts here for the column COL_C, what does the difference is the 86k records of value 0.
