I'm trying to declare local temporary table using the example from Oracle / PLSQL: LOCAL TEMPORARY TABLES. But when I try to insert it into sqlplus' CLI and hit Enter, it does not execute anything and I don't know what to do next to complete the command except pressing Ctrl+C interrupting command inputing:
SQL> DECLARE LOCAL TEMPORARY TABLE suppliers_temp
( supplier_id number(10) NOT NULL,
supplier_name varchar2(50) NOT NULL,
contact_name varchar2(50)
); 2 3 4 5
6
7 ;
8 ^C
To execute this query I've logged in as SYSTEM user.
Why this example does not work for me?
local temporary tables aren't a thing in the Oracle RDBMS. Instead, you can have a Global Temporary Table (GTT) (which creates a permanent table, but the data is held at session level) or, introduced in 18c, you can have a Private Temporary Table (PTT) (the table definition and data are held at session level).
Both are similar to the standard create table statement, so to create a GTT that drops the rows when you commit, you would do something like:
create global temporary table table_name (col1 number, col2 varchar2(20))
on commit delete rows;
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 am going to develop a reporting database by querying the production database once using a stored procedure.
The stored procedure will then write the result into it's own output tables.
Following is the schema for the output table:
Create table Output (
Customer_ID NUMBER(15) not null,
STD_HASH RAW(1000 BYTE) ,
VALID_PERIOD_START NOT NULL TIMESTAMP(6),
VALID_PERIOD_END NOT NULL TIMESTAMP(6),
Address VARCHAR2(30 CHAR),
period for valid_period(valid_period_start,valid_period_end),
Constraint Output_PK Primary Key ( Customer_ID, valid_period_start, valid_period_end )
)
As the stored procedure will perform a lot of update and delete statement on the output table, and those output table is very big. The largest one I have right now is 8GB. I am thinking to alter those output tables with the "SHRINK SPACE" option at the end of the stored procedure to reclaim some spaces.
Following is the statement that I am going to apply:
Alter table OUTPUT1 ENABLE ROW MOVEMENT; -- Temporary enable row movement for the table
Alter TABLE output2 SHRINK SPACE;
Alter table OUTPUT1 DISABLE ROW MOVEMENT;-- Disable row movement.
Those output tables are temporal table that is using the valid period and the ID from production as a primary key.
However, as I am very new with the Shrink Space function. Can anyone tell me what is the disadvantage of using this function?
The table, basically will not be updated from anywhere other than this stored procedure. The stored procedure will be scheduled to run in a daily base.
Thanks in advance!
yes, shrink has some restrictions:
(1) it locks the table during the shrink operation
(2) it change the rowid of the table.
(3) it needs the tablespace with automatic segment-space management enabled.
we have other alternatives to claim the unused space:
(1) export/import
(2) dbms_redefinition
Iam facing a issue while altering the GTT table.
I need to find the active users on that table, Can someone help in query regarding how to find the active users on the specific object in oracle database
As far as I can tell, you didn't explain what problem you're trying to solve, but rather what you think that might help you solve it. So, let me try to guess.
Here's a global temporary table (GTT):
SQL> create global temporary table gtt (id number) on commit preserve rows;
Table created.
SQL> insert into gtt values (1);
1 row created.
SQL> commit;
Commit complete.
You're trying to alter it, but - it fails:
SQL> alter table gtt add name varchar2(10);
alter table gtt add name varchar2(10)
*
ERROR at line 1:
ORA-14450: attempt to access a transactional temp table already in use
OK, so - delete row(s) and commit, then try again:
SQL> delete from gtt;
1 row deleted.
SQL> commit;
Commit complete.
SQL> alter table gtt add name varchar2(10);
alter table gtt add name varchar2(10)
*
ERROR at line 1:
ORA-14450: attempt to access a transactional temp table already in use
Still no luck. But, if you truncate the table, then it works:
SQL> truncate table gtt;
Table truncated.
SQL> alter table gtt add name varchar2(10);
Table altered.
SQL>
If that's not what you're after, then see if this answers your question: connect as a privileged user (such as SYS, if you don't have any other) and run such a query: it shows who owns the GTT, its name, who locked it (which Oracle user) and which operating system user is it (that might help you to contact those people):
SQL> select b.owner,
2 b.object_name,
3 a.oracle_username,
4 a.os_user_name
5 from v$locked_object a, dba_objects b
6 where a.object_id = b.object_id;
OWNER OBJECT_NAM ORACLE_USERNAME OS_USER_NAME
--------------- ---------- --------------- ------------------------------
SCOTT GTT SCOTT littlefoot
SQL>
I need import utility to remove old data then reinsert new data. How can I do that without using data pump?
The reason I can't use data pump is because I need to run this script on application server, I don't have the privilege to run this on database server. below is the script I'm currently trying to fix
imp < username >/< password >#//< host > fromuser=< schema > touser=< schema > file=exp_$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>
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