In one of my Windows form application in asp .net, I am creating tables on daily basis sharp at 00:00 am with name as "data_YYYY_MM_DD" in Oracle database. A large amount of data exist in each table as after every 5 seconds I am writing some useful data into these.
Now consider all tables of month Oct 2016. All will have name like 'data_2016_10%'. How can I take backup of only these tables (not backup of entire database) and then drop these tables from the database.
You can take logical backup of these tables using data pump. It creates dump file(binary file) which can be imported as per your needs.
Export:Table Mode
A table mode export is specified using the TABLES parameter. In table mode, only a specified set of tables, partitions, and their dependent objects are unloaded.
Example:
expdp hr TABLES=hr.employees VERSION=LATEST DIRECTORY=dpump_dir1 DUMPFILE=emp.dmp NOLOGFILE=YES
Reference:
Data Pump Export
Try like below,
you can schedule it in dbms_scheduler jobs,So that every day it will run and create backup table and drop existing table.Also please add exceptions like table does not exist...if you want
create or replace procedure backup_monthly_table
as
prev_date varchar2(20) := to_char(sysdate-1, 'yyyy-mm-dd');
begin
for i in (select table_name from dba_tables where upper(table_name) like '%'||'"'||prev_date||'_%')
loop
dbms_output.put_line('working');
dbms_output.put_line(i.table_name);
execute immediate 'create table sysman.'||'"'||i.table_name||'_bkp'||'"'||' as select * from sysman.'||'"'||i.table_name||'"';
execute immediate 'drop table sysman.'||'"'||i.table_name||'"';
end loop;
end;
verification output:
select owner,table_name from dba_tables where upper (table_name) like '%2017-%'
SYSMAN 2017-02-01_test1_bkp
SYSMAN 2017-02-01_test2_bkp
SYSMAN 2017-02-01_test3_bkp
SYSMAN 2017-02-01_test4_bkp
Related
Probably I ask for the impossible, but I'll ask anyway.
Is there an easy way to select from one Oracle session and then insert/commit into another?
(I guess, technically it could be done with pl/sql procedure calls and PRAGMA AUTONOMUS Transactions, but it would be a hassle)
I have the following scenario:
I run some heavy calculations and update / insert into some tables.
After the process is completed I would like to 'backup' the results
(create table as select or insert into another temp table) and then rollback my current session without loosing the backups.
Here is desired/expected behavior:
Oracle 11g
insert into TableA (A,B,C) values (1,2,3);
select * from TableA
Result: 1,2,3
create table [in another session] TempA
as select * from TableA [in this session];
rollback;
select * from TableA;
Result null
select * from TempA;
Result 1,2,3
Is this possible?
Is there an easy way to select from one Oracle session and then insert/commit into another?
Create a program in a third-party language (C++, Java, PHP, etc.) that opens two connections to the database; they will have different sessions regardless of whether you connect as different users or both the same user. Read from one connection and write to the other connection.
you can insert your "heavy calculation" into a Oracle temp Table .
CREATE GLOBAL TEMPORARY TABLE HeavyCalc (
id NUMBER,
description VARCHAR2(20)
)
ON COMMIT DELETE ROWS;
the trick is that when you commit the transaction all rows are deleted from temporary table.
Then you first insert data into the temp table, copy the result to you backup table and commit the transaction.
I need import utility to remove old data then reinsert new data. How can I do that without using data pump?
The reason I can't use data pump is because I need to run this script on application server, I don't have the privilege to run this on database server. below is the script I'm currently trying to fix
imp < username >/< password >#//< host > fromuser=< schema > touser=< schema > file=exp_$TODAY.dmp log=exp_import_$TODAY.log ignore=y
IMP can't truncate tables prior to importing, so - you're out of luck here. If you could use the Data Pump Import, you could use the TABLE_EXISTS_ACTION parameter set to TRUNCATE (which would remove existing data) or even REPLACE (which drops table, creates it and loads data). Ask the DBA to provide access to a directory you could use for importing purposes.
Alternatively, as it seems that you're importing everything, consider dropping the target user (with the cascade option) and then import its objects.
Or, if it isn't too complicated, create a script which would truncate tables, for example
SQL> select 'truncate table ' || tname ||';' from tab;
'TRUNCATETABLE'||TNAME||';'
----------------------------------------------
truncate table BONUS;
truncate table DEPT;
truncate table EMP;
truncate table SALGRADE;
truncate table WC;
SQL>
so you'd run those TRUNCATE TABLE statements prior to importing.
Note that - if there are foreign key constraints - they won't let you do it unless you disable them; as above, you could use SQL to create SQL for you:
SQL> select 'alter table ' || table_name || ' disable constraint ' || constraint_name ||';'
2 from user_constraints
3 where constraint_type = 'R';
'ALTERTABLE'||TABLE_NAME||'DISABLECONSTRAINT'||CONSTRAINT_NAME||';'
---------------------------------------------------------------------------------------------
alter table EMP disable constraint FK_DEPTNO;
SQL>
I am searching for a way, to store only the tables and columns that are added in the database with the one who created it (nachine_name) in a log table.
I tried to add a trigger on sys table user_tab_cols but I cannot do that Why cannot I create triggers on objects owned by SYS?
The system table user_objects will give me the date when a table created, but I want also to know which machine created it. and I also want to track the column creation and modification and log them in a table.
Is that possible ? is there a way for that ?
you can create a database event trigger:
CREATE OR REPLACE TRIGGER log_ddl_event_trg
AFTER DDL
ON DATABASE
DECLARE
v_sql_list ora_name_list_t;
v_sql_txt VARCHAR2(2500);
BEGIN
FOR i in 1..ORA_SQL_TXT(v_sql_list) LOOP
v_sql_txt := v_sql_txt || v_sql_list(i);
EXIT WHEN length(v_sql_txt ) >= 2000;
END LOOP;
...
END;
/
in the Trigger, you can get the executed ddl-statement using the ORA_SQL_TXT() Funktion, and then log it in the table together with the other data (log_date, user etc.).
I have a big problem When i take a dump of database the empty tables are truncated
How i can export the all tables in oracle 10g
exp SYSTEM/password FILE=expdat.dmp
This might be because of these tables may not be extent allocated. Before taking backup you need to identify all the tables that do not have data. Then alter these tables to allocate extent.
ALTER TABLE <table_name> ALLOCATE EXTENT;
Use the below script to alter all tables they do not have extent allocated.
SELECT 'ALTER TABLE '||table_name||' ALLOCATE EXTENT;' FROM user_tables WHERE segment_created = 'NO';
Copy the output and execute it.
You might consider expdp (data pump) instead. There's a parameter CONTENT=METADATA_ONLY that might get you what you want.
I found another solution here.
Oracle has an option called DEFERRED_SEGMENT_CREATION, default true.
from the docs:
If set to true, then segments for tables and their dependent objects (LOBs, indexes) will not be created until the first row is inserted into the table.
I'll sum up the solution from the above link:
SQL> alter system set DEFERRED_SEGMENT_CREATION=FALSE scope=both;
Run the output of the following statement:
SQL> select 'alter table ' || table_name || ' move;' from user_tables where num_rows=0;
This made my exp export empty tables as well.
I need to create a table every morning based on overnight generated data from a massive table. This will then be accessed by a handful of users form Excel.
My initial approach was to use a materilazed view and when this was rejected (for political reasons) to used Managed XLL but this was rejected for other reasons. I don't want to get messed up with Temporary tables and so really just need to know how to schedule an Oracle Create Table statement as our DBA says it can't be done.
My faith in SO users sasy otherwise though!
I don't see why you have to create a new table every morning and not use an existing one?
This creates your table from PL/SQL. Is this what you want?
CREATE OR REPLACE PROCEDURE make_table AS
BEGIN
EXECUTE IMMEDIATE 'CREATE TABLE your_table ( column_1 INT PRIMARY KEY, column_2 VARCHAR2(10) )';
END make_table;
/
EXEC make_table;
Your user needs to have the necessary grants, grants given by role don't apply to compiled PL/SQL code.