Create table taking much longer than select sql oracle - oracle

I have a select query running on an oracle database that takes only about fifteen seconds to run. However when I try to create a table from this, either using a create select as or creating a blank table and inserting the rows, the create just keeps running and running (so far I've waited up to fifteen minutes with no result).
Below is my attempt at the create blank then insert method, which shows the structure of the table I'm creating and the data I'm trying to insert:
CREATE TABLE MYNEWTABLE
(mykey number(10), brand varchar2(255), day_id number(10), adateone date, p_id number (10), startdate date, enddate date, another_day_id number(10))
INSERT INTO MYNEWTABLE
select ns.mykey, ns.brand, oc.day_id, oc.day_date as adateone, tbut.p_id, tbut.startdate, tbut.enddate, cust.another_day_id
from TABLE_1 ns
RIGHT JOIN TABLE_2 tbut
ON ns.mykey = tbut.mykey
LEFT JOIN
TABLE_3 cust
ON ns.mykey = cust.mykey
LEFT JOIN DATE_TABLE oc
on cust.first_del_day_id = oc.day_id
where ns.brand = 'SOME VALUE'
What is the cause of the table's creation being so slow and how can I improve this?
Many thanks.

When any session hangs, the appropriate thing to check is V$SESSION_WAIT.
Execute,
select * from v$session_wait where sid = <your sid>
Depending on the result of the wait, you need to figure out which session is holding the lock you are waiting for.

Looks like your SQL runs using nested loops. So 15 seconds it is time to return first N rows (where n depends on your client tool). When you start to fetch all rows and insert into new table it takes more time.

Related

Delete logic is taking a very long time to process in Oracle

I am trying to use the following statement for the Delete process and it has to delete around 23566424 Rows, but oracle takes almost 3 hours to complete the process and we have already created an index on " SCHEDULE_DATE_KEY" but still, the process is very slow.Can someone advise on how to make Deletes faster in oracle
DELETE
FROM
EDWSOURCE.SCHEDULE_DAY_F
WHERE
SCHEDULE_DATE_KEY >
(
SELECT
LAST_PAYROLL_DATE_KEY
FROM
EDWSOURCE.LAST_PAYROLL_DATE
WHERE
CURRENT_FLAG = 'Y'
);
I don't think any index will help here, probably Oracle will decide the best approach is a full table scan to delete 20M rows from 300M. It is deleting at a rate of over 2000 rows per second, which isn't bad. In fact any additional indexes will slow it down as it has to delete the row entry from the index as well.
A quicker approach could be to create a new table of the rows you want to keep, something like:
create table EDWSOURCE.SCHEDULE_DAY_F_KEEP
as
select * from EDWSOURCE.SCHEDULE_DAY_F
where SCHEDULE_DATE_KEY <=
(
SELECT
LAST_PAYROLL_DATE_KEY
FROM
EDWSOURCE.LAST_PAYROLL_DATE
WHERE
CURRENT_FLAG = 'Y'
);
Then recreate any constraints and indexes to use the new table.
Finally drop the old table and rename the new one.
You can try testing a filtered table move. This has an online clause. So you can do this while the application is still running.
Note 12.2 and later the indexes will remain valid. In earlier versions you will need to rebuild the indexes as they will become invalid. Good Luck
Move a Table
Create and populate a new test table.
DROP TABLE t1 PURGE;
CREATE TABLE t1 AS
SELECT level AS id,
'Description for ' || level AS description
FROM dual
CONNECT BY level <= 100;
COMMIT;
Check the contents of the table.
SELECT COUNT(*) AS total_rows,
MIN(id) AS min_id,
MAX(id) AS max_id
FROM t1;
TOTAL_ROWS MIN_ID MAX_ID
---------- ---------- ----------
100 1 100
SQL>
Move the table, filtering out rows with an ID value greater than 50.
ALTER TABLE t1 MOVE ONLINE
INCLUDING ROWS WHERE id <= 50;
Check the contents of the table.
SELECT COUNT(*) AS total_rows,
MIN(id) AS min_id,
MAX(id) AS max_id
FROM t1;
TOTAL_ROWS MIN_ID MAX_ID
---------- ---------- ----------
50 1 50
SQL>
The rows with an ID value between 51 and 100 have been removed.
As mentioned above if maybe best to PARTITION the table abs drop a PARTITION every N number of days as part of a daily task.

how to use or create temp table in Oracle

I am pretty new to Oracle.
I am just stuck when i try to achieve the following logic. I am creating a sql script in oracle that will help me to generate a report. This script will run twice a day so i should't pick the same file when it runs next time.
1) run the query and save the result setand store the Order Id in the temp table when the job runs #11 Am
2) Run the query second time # 3 pm check the temp table and return the result set that's not in temp table.
Following query will generate the result set but not sure how to create a temp table and valid against when it run.
select
rownum as LineNum,
'New' as ActionCode,
ORDER_ID,
AmountType,
trun(sysdate),
trun(systime)
from crd.V_IVZ_T19 t19
where
(t19.acct_cd in
(select fc.child_acct_cd
from cs_config fc
where fc.parent_acct ike 'G_TRI_RPT'))
and t19.date>= trunc(sysdate)
and t19.date<= trunc(sysdate);
Any help much appreciated. I am not sure how to get only the timestamp also.
TEMP table is not the idea here, cause temp table data will not store the data for a long time (just for a session), you just need to create a normal table. Hope it will help you:
--- table for storing ORDER_ID for further checking, make a correct DataType, you also can add date period in the table to control expired order_ids';
CREATE TABLE order_id_store (
order_id NUMBER,
end_date DATE
);
--- filling the table for further checking
INSERT INTO order_id_store
SELECT ORDER_ID, trunc(sysdate)
FROM crd.V_IVZ_T19 t19
WHERE t19.order_id NOT IN (SELECT DISTINCT order_id FROM order_id_store)
AND t19.date>= trunc(sysdate)
AND t19.date<= trunc(sysdate);
--- delete no need data by date period, for example for last 2 days:
DELETE FROM order_id_store WHERE end_date <= trunc(SYSDATE - 2);
COMMIT;
---- for select report without already existed data
SELECT
rownum as LineNum,
'New' as ActionCode,
ORDER_ID,
AmountType,
trun(sysdate),
trun(systime)
FROM crd.V_IVZ_T19 t19
WHERE
(t19.acct_cd in
(select fc.child_acct_cd
from cs_config fc
where fc.parent_acct ike 'G_TRI_RPT'))
AND t19.order_id NOT IN (SELECT DISTINCT order_id FROM order_id_store)
AND t19.date>= trunc(sysdate)
AND t19.date<= trunc(sysdate);
I'm not sure about your "t19.date>=" and "t19.date<=", cause the close duration taking there, make that correct if it's not.

Keeping track of all values created by a sequence for multiple inserts

In PL SQL, I'm writing a stored procedure that uses a DB link:
CREATE OR REPLACE PROCEDURE Order_Migration(us_id IN NUMBER, date_id in DATE)
as
begin
INSERT INTO ORDERS(order_id, company_id)
SELECT ORDER_ID_SEQ.nextval, COMPANY_ID
FROM ORDERS#SOURCE
WHERE USER_ID = us_id AND DUE_DATE = date_ID;
end;
It takes all orders done on a certain day, by a certain user and inserts them in the new database. It calls a sequence to makes sure there are no repeat PKs on the orders, and it works well.
However, I want the same procedure to do a second INSERT into another table that has order_id as a foreign key. So I need to add all the order_id's just created, and the data from SOURCE that matches:
INSERT INTO ORDER_COMPLETION(order_id, completion_dt)
SELECT ????, completion_dt
FROM ORDER_COMPLETION#SOURCE
How can I keep track of which order_id that was just created matches up to the one whose data I need to pull from the source database?
I looked into making a temporary table, but you can't create those in a procedure.
Other info: I'll be calling this procedure from a C# app I'm writing
I'm not sure that I follow the question. If there is an ORDERS table and an ORDER_COMPLETION table in the remote database, wouldn't there be some key on the source system that related those two tables? If that key is the ORDER_ID, why would you want to re-assign that key in your procedure? Wouldn't you want to maintain the ORDER_ID from the source system?
If you do want to re-assign the ORDER_ID locally, I would tend to think that you'd want to do something like
CREATE OR REPLACE PROCEDURE order_migration( p_user_id IN orders.user_id%type,
p_due_date IN orders.due_date%type )
AS
TYPE order_rec IS RECORD( new_order_id NUMBER,
old_order_id NUMBER,
company_id NUMBER,
completion_dt DATE );
TYPE order_arr IS TABLE OF order_rec;
l_orders order_arr;
BEGIN
SELECT order_id_seq.nextval,
o.order_id,
o.company_id,
oc.completion_dt
BULK COLLECT INTO l_orders
FROM orders#source o,
order_completion#source oc
WHERE o.order_id = oc.order_id
AND o.user_id = p_user_id
AND o.due_date = p_due_date;
FORALL i IN l_orders.FIRST .. l_orders.LAST
INSERT INTO orders( order_id, company_id )
VALUES( l_orders(i).new_order_id, l_orders(i).company_id );
FORALL i IN l_orders.FIRST .. l_orders.LAST
INSERT INTO order_completion( order_id, completion_dt )
VALUES( l_orders(i).new_order_id, l_orders(i).completion_dt );
END;
You could also do a single FOR loop with two INSERT statements rather than two FORALL loops. And if you're pulling a lot of data each time, you probably want to pull the data in chunks from the remote system by adding a loop and a LIMIT to the BULK COLLECT
There must be some link between the rows in ORDERS#SOURCE and ORDERS, and between ORDERS#SOURCE and ORDER_COMPLETION#SOURCE, so can you not use a join?
Something like:
INSERT INTO ORDER_COMPLETION(order_id, completion_dt)
SELECT o.order_id, ocs.completion_dt
FROM ORDER_COMPLETION#SOURCE ocs
JOIN ORDERS o ON o.xxx = ocs.xxx

Ensure Oracle row represents a unique timespan

I have to make a process in Oracle/PLSQL. I have to verify that the interval of time between start_date and end_date from a new row that I create must not intersect other start_dates and end_dates from other rows.
Now I need to check each row for that condition and if it doesn't correspond the repetitive instruction should stop and after that to display a message such as "The interval of time given is not correct".
I don't know how to make repetitive instructions in Oracle/PLSQL and I would appreciate if you would help me.
I need a loop or smth like that to verify each row in my table that the interval of time given by the date_hour_i and date_hour_e does not intersect the other intervals of time given by the rest of the rows. One more specification....the dates from each row correspond to a client and a employee that performs a haircut to the client in the given interval of time....and i want somehow not to let to introduce a new row if for the same client(or other client) and employee, the new interval of time intersects the other intervals of time with the same/other client and employee....i hope i made myself clear...
Two links for your reading pleasure:-
Time intervals with no overlaps
and
Avoiding overlap values...
why check each row? just query for the start and end times. if the result > 0, output the error message, else, insert.
i assume this will be during the BEFORE INSERT OR UPDATE trigger.
you will want to query the existing table for overlaps in the dates - but this will give a mutating trigger error.
You can get around this by using PRAGMA AUTONOMOUS_TRANSACTION to spawn a new thread.
alternately - you could save each date range in a secondary table, and use that to query against on each insert... something like the following (uncompiled)
CREATE OR REPLACE TRIGGER mytrigger
BEFORE INSERT OR UPDATE ON mytable FOR EACH ROW
DECLARE
cnt number;
BEGIN
SELECT count(*) into cnt
FROM reserved_date_range
WHERE :new.begin_date BETWEEN begin_dt and end_dt
if ( cnt > 0 ) then
raise_application_error(-20000,'Overlapping date ranges');
else
insert into reserved_date_range( begin_dt, end_dt )
values ( :new.begin_date, :new.end_date );
end if;
End;
/
Say your table is tab1 and the start date is stdate and end date is endate
also let new start date and new end date be in PLSQL variables v_stdate and v_endate.
so your insert can be something like
insert into tab1 (stdate,endate)
select v_stdate,v_endate from dual
where not exists(
select 'overlap' from tab1 t1
where v_stdate between(t1.stdate and nvl(t1.endate,v_endate)
or v_endate between(t1.stdate and nvl(t1.endate,v_endate)
)
The solution to this problem is a bit complicated because of concurrency issues. In your case you are scheduling an event (or a resource).So I suppose you have a table that holds resource (say client). Before you add another schedule (or event) for a client you should lock the particular client record like.
select client_id from Clients where client_id=p_client_id for update;
Then you can verify there are no overlaps and insert the new schedule and commit.At this point the lock will be released.Any solution that does not use a serialization object is bound to be flawed due to concurrency issues.You can do it in your PLSQL or in a After Insert trigger.But it is an absolute must to lock the actual resource record.

How to duplicate all data in a table except for a single column that should be changed

I have a question regarding a unified insert query against tables with different data
structures (Oracle). Let me elaborate with an example:
tb_customers (
id NUMBER(3), name VARCHAR2(40), archive_id NUMBER(3)
)
tb_suppliers (
id NUMBER(3), name VARCHAR2(40), contact VARCHAR2(40), xxx, xxx,
archive_id NUMBER(3)
)
The only column that is present in all tables is [archive_id]. The plan is to create a new archive of the dataset by copying (duplicating) all records to a different database partition and incrementing the archive_id for those records accordingly. [archive_id] is always part of the primary key.
My problem is with select statements to do the actual duplication of the data. Because the columns are variable, I am struggling to come up with a unified select statement that will copy the data and update the archive_id.
One solution (that works), is to iterate over all the tables in a stored procedure and do a:
CREATE TABLE temp as (SELECT * from ORIGINAL_TABLE);
UPDATE temp SET archive_id=something;
INSERT INTO ORIGINAL_TABLE (select * from temp);
DROP TABLE temp;
I do not like this solution very much as the DDL commands muck up all restore points.
Does anyone else have any solution?
How about creating a global temporary table for each base table?
create global temporary table tb_customers$ as select * from tb_customers;
create global temporary table tb_suppliers$ as select * from tb_suppliers;
You don't need to create and drop these each time, just leave them as-is.
You're archive process is then a single transaction...
insert into tb_customers$ as select * from tb_customers;
update tb_customers$ set archive_id = :v_new_archive_id;
insert into tb_customers select * from tb_customers$;
insert into tb_suppliers$ as select * from tb_suppliers;
update tb_suppliers$ set archive_id = :v_new_archive_id;
insert into tb_suppliers select * from tb_suppliers$;
commit; -- this will clear the global temporary tables
Hope this helps.
I would suggest not having a single sql statement for all tables and just use and insert.
insert into tb_customers_2
select id, name, 'new_archive_id' from tb_customers;
insert into tb_suppliers_2
select id, name, contact, xxx, xxx, 'new_archive_id' from tb_suppliers;
Or if you really need a single sql statement for all of them at least precreate all the temp tables (as temp tables) and leave them in place for next time. Then just use dynamic sql to refer to the temp table.
insert into ORIGINAL_TABLE_TEMP (SELECT * from ORIGINAL_TABLE);
UPDATE ORIGINAL_TABLE_TEMP SET archive_id=something;
INSERT INTO NEW_TABLE (select * from ORIGINAL_TABLE_TEMP);

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