I'm currently working on a project which is to archive the old data and then purge the same data from the main table.
Here is a detail description:
There are around 50 odd tables from which I would need to archive the old data(matching certain filter conditions...not date based). Meaning I have to store the data in a temp table. Once stored in temp table then I would have to delete those rows from the main table. This temp table will be later exported and stored on ARchive database(a seperate database). These tables are very huge. One of the table is actually 250 GB in size. And all these tables have many indexes built - both normal and bitmap.The 250 GB size table has 40 million rows that need to be archived and purged. The total number of rows in the table are 540 million.On this table alone there are 50 bitmap indexes and 2 normal indexes. This table is partitioned based on date column.This date column is not used/useful in identifying the old data. There are around 20 tables which are quite similar in size to the above described table. Rest of them are little small when compared to the above table.
We have to execute this activity over a weekend which gives us about 48 hours time to complete the activity. Best possible ways to handle this activity. Most importantly should be able to complete the activity within the specified 48 hour window.
The solution what we are now thinking of is:
1. Create the temp table ---Create tmp_tbl as select * from main_table where <<conidtions identifying old data>>
2. Once the temp table is created. Make copy of indexes that exist on the main table and eventually drop them.
3. Execute a PL/SQL script to perform the bulk delete from main table and commit for every 100000 rows.
4. Once the bulk delete is finished then recreate the indexes on the main table using the copy made at earlier step.
Our main worry is about the step#4. Considering the size of these tables and the number of indexes to be built,we are not sure how long the index re-creation will run for each table.
depending on the possibilities we may have to split the activity in to 2-3 phases spreading across 2-3 weekends. Even then we are not sure whether we will be able to pull off this activity.
We have a huge table in production, with LONG column. We are trying to change its datatype to CLOB. The table has 120 Million records and is of 270 GB in size.
We tried using the oracle expdp/impdp option to try the conversion in our perf environment. With 32 parallels, the export completed in 1.5 hrs. However, the import took 13 hrs.
I also tried the to_lob option using inserts, it went on for 20 hrs and I killed the process. Are there any ways to improve the performance of LONG to CLOB conversion on huge tables?
Here is my problem, i need to create some files with my own format(let say 5000 records each) from a huge data table (May contain 5 Million records). And i want this creation to be multi threaded.
so how can i form queries efficiently to fetch records like 1..5000 and 5001..10000 and so on. I can form some thing like select * from table where rownum<5000 and not exists ( already fetched records) . but it is not the efficient one.
I have 2 questions, because they can be inter-related I am posting it in a single post. These queries are related to Oracle(PL\SQL).
1. I am trying to increase the size of a field in a table which has almost 2 million records and the query for alteration runs for almost and hour and rollsback, wondering is there a better way of doing it.
2. I have modified the size of a field in a table from Varchar2(10) to Varchar2(20), now when I tried to rollback the modification it is not letting me to change the size from Varchar2(20) to Varchar2(10). No data has been inserted after the modification.
I have 2 questions, because they can be inter-related I am posting it in a single post. These queries are related to Oracle(PLSQL).
1. I am trying to increase the size of a field in a table which has almost 2 million records and the query for alteration runs for almost and hour and rollsback, wondering is there a better way of doing it.
2. I have modified the size of a field in a table from Varchar2(10) to Varchar2(20), now when I tried to rollback the modification it is not letting me to change the size from Varchar2(20) to Varchar2(10). No data has been inserted after the modification.
Need to change the precision of a column in a existing table. Statistics about the table
* has over 130 columns * More than 300 million records * Column to modify is #121 which has data * No primary key defined
Since the column has data, it is not possible to modify with a simple Alter.
Second option - create temp column in same table, update from original, put null in original, alter, update back from temp, drop the temp column. This approach is very expensive and time consuming.
I am trying to delete 3 million records of data from huge table which already consists of 3 billion records.
This is hitting performance of DB and halting other activities of my users. Is there any easy way to delete such data fast. I have tried with forall delete but it is even taking lot of time.
I have table which contains huge data. around 12 lakhs records. when I use sum function on accountname and docdate it gives wrong value. once I restart the server it gives the correct value. one or two days it gives correct value after that again I get the same problem. If I restart again it gives correct value.
I use Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 64 bit server on Linux.
extract a huge amount of data from a couple of views... the problem is that they want it in TXT files with fixed record length. There will be like 6 files, for a total amount of about 10GB.
export those tables in the fastest possible way? If I'm not mistaken exp and expdp can't create txt files, so do I really need to use utl_file or spool?
I need to read a huge number of rows, say in lakhs and then need to populate it in data block. Since it is having huge data am never able to run the form. it hangs after some time. when i test with few rows it is working. so no problem in coding.
I have written a purge package that would delete records older than 10 years. Since the data is huge, the purging was taking 14 hours plus. To improve performance, I disabled constraints , deleted records and then reanabled them. This was quite quick but the only problem is rollback. Say for some reason if enabling constraints fails there is no way to rollback as enabling and disabling constraints does an implicit rollback.
I want to purge a table which is having more then 98M rows...here are the details...
Purge Process I followed --------------------------------------------- Step 1. Created backup table from Main table with required data only create table abc_98M_purge as select * from abc_98M where trunc(tran_date)>='01-jul-2011' -> table created with 5325411 rows
Step 2. truncate table abc_98M
Step 3. inserted all 5325411 rows back to abc_98M from abc_98M_purge using below procedure
DECLARE TYPE ARRROWID IS TABLE OF ROWID INDEX BY BINARY_INTEGER; tbrows ARRROWID; row PLS_INTEGER; cursor cur_insert is select rowid from abc_98M_purge order by rowid; BEGIN open cur_insert; loop [code]....
BANNER -------------------------------------------------------------------------------- Oracle Database 11g Enterprise Edition Release 11.1.0.7.0 - 64bit Production PL/SQL Release 11.1.0.7.0 - Production CORE 11.1.0.7.0 Production TNS for Linux: Version 11.1.0.7.0 - Production NLSRTL Version 11.1.0.7.0 - Productionredo logs multiplexed. [code]....
+ when the redolog 5 was archived how the archiving process works ?
let say both the log members are clean in case which one will be archived 5a or 5b ?
+ I can also see only one archive log is creating during log swtich
I am working on an archiving strategy. I want to roll off transactions that are older than seven days, but only if they are flagged as Completed. The numbers of transactions are very large so this is a worthwhile venture.
The only strategy I have been able to come up with so far is to partiton on date. Then when 7 days comes up, sweep the about-to-be archived day for the few remaining not Completed transactions, put those into a new table (a new version of this partiton) and switch partitions. Each day I do this until the older parititions are empty.
I just want to write some data in a particular table,But I dont want it to be archivedSo is it possible to disable archiving in session level Oracle 11g Rel 2
RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03009: failure of sql command on default channel at 01/26/2013 22:48:56 RMAN-11003: failure during parse/execution of SQL statement: alter system archive log current ORA-00258: manual archiving in NOARCHIVELOG mode must identify log RMAN>
I have to cleanup data from our tables (Production Environment) that contain millions of rows. The question is apart from the solution of the partitioned tables what alternative recommended solution suggests Oracle?
To delete these tables by using a cursor PL/SQL block or to import all the database and in the tables that we want to remove the old rows to use the QUERY option of the data pump utility.
I have used both ways and i have to admit that datapump solution is much much faster than the deletion that suffers from I/O disk.The question again is which method from these two is more reliable and less risky for the health of the database.
I came across an implementation where data from DB2 tables are moved to Oracle tables, for BI solutioning, using some oracle procedures called from MS SQL DTS packages which are scheduled jobs.Just being curious, can this be done using OWB or ODI rather than the above detour. I suppose there are some changes being done in those procedures before the data is being loaded into Oracle tables, can't this be done using OWB/ODI? Can it be scheduled too as jobs using OWB/ODI?
I need to export only the data from schemas or tables, how to do that with Oracle Data Pump? when we use schemas parameter this export all schema, not only the data right?
I created a data warehouse in oracle 10g n with three Dimension and one cube after that it crates 4 tables . How to use an insert sql statement to insert data in those tables n how to access them.
Consider tables A,B,C,D,E,F. all are having 100000++ records Tables B,C,D are dependent on table A (with foreign key constraint). When I am deleting records from all tables, table B,C,D are taking max 30-40 seconds while table A is taking 30-40 mins. All tables are having indexes.
Method I have used:
1. Created Temp table
2. then deleted all records from B,C,D,E,F for all records in temp table for limit of 500.
delete from B where exists (select 1 from temp where b.col1=temp.col1);
3. why it is taking too much time for deleting records in table A.
I have a table which have 300+ columns and have 13 million rows. It is on a 32 kb block size. This is a table in data ware house environment. There no# of rows in the table haven't changed much but I see that the time taken to collect statistics have increased significantly.Initially it took only 15 minutes (with the same 13M rows) now it runs for 4+ hours. The max parallel servers is 4 (which is unchanged). The table is not partitioned.
OS: HP UX Itanium Database: Oracle 11g (11.2.0.2)
Command is: exec dbms_stats.gather_table_stats(ownname=>'ABC',tabname=>'ABC_LOAD',estimate_percent=>dbms_stats.auto_sample_size,cascade=>TRUE,DEGREE=>dbms_stats.auto_degree);
I would like to understand:
1) What could have been the causes of this change in time. 15 minutes to 4+hours ? 2) How can we gather statistics of huge table at a faster rate?
I need to verify huge number of records in two different databases. Basically i wanted to check if same record exist in other database's table or not? but as the number of records are more than billions who would i verify?
checking record one by one would be so hectic and time consuming. any other option is there?
create table ACTIONARI_ARH ( actionar_id NUMBER(10) not null, id VARCHAR2(20) not null, id_2 VARCHAR2(20), tip VARCHAR2(1), nume VARCHAR2(100), prenume VARCHAR2(100), adresa VARCHAR2(200),
[code]....
and this view
CREATE OR REPLACE VIEW ACTIONARI AS SELECT "ACTIONAR_ID","ID","ID_2","TIP","NUME","PRENUME","ADRESA","LOCALITATE","JUDET","TARA","CERT_DECES","DATA_REGISTRU" Data_operare,"USER_MODIF","DATA_MODIF","REZIDENT" FROM ( select
[code]....
The table has about 30 milion records and holds persons names, addresses, personal id (id), and internal id(actionar_id) and date when a new adress has been added.
The view is about getting only the most recent info for one person (actionar_id).
if i run a
a) select * from actionari a where a.actionar_id = 'nnnnnnn', result is returned immediatly, oracle uses index and does not do a full table scan.
b) select * from actionari a where a.actionar_id in ('nnnnnnn','mmmmmm','ooooooo'), result is returned immediatly, oracle uses index and does not do a full table scan.
my problem when i use this view in a join.let's assume i have another table with no more than 500 records, something like
create table SMALL_TABLE ( actionar_id NUMBER(10) not null, ...... );
and if i run
select * from SMALL_TABLE s join actionari a on a.actionar_id = s.actionar_id;
it takes like forever to process, forever means 1~3 minutes.by looking at the execution plan, oracle does a full table scan, creates the view for all unique 7milion persons, and only then joins the result with the actionar_is's in the small table and returns the desired 500 record result.i am using oracle 10g.
