Whenever I try to drop a sequence I get the following error:-
DROP SEQUENCE seq_12129;
DROP SEQUENCE: unable to drop sequence seq_12129 (there are database objects which depend on it)
I have dropped all the tables in the current schema, but I am still getting this error. Is there a way to find out what database object depends on this sequence?
Related
Is it possible to create a hive view on top of a nonexistent hive table or views?. This ability will help us deploy the hive DDL without any order at the time of refresh (migrating tables or views from one environment to another). In our environment, we have views built on top of another view. If we deploy them in any order, with the default setup some of the views may fail saying the underlying table/view doesn't exist. Looking to see if we can turn off the metadata lookup from hive metastore so that the type checks are not done at the time of view creation. It can be enforced after the deployment or at the time of querying the view for data retrieval because by that time all the views/tables will be completely deployed and there won't be any type checking related errors.
I checked on the internet for pointers but I couldn't find any. Any suggestions in this regard will be helpful to us.
Thanks in advance.
Add IF NOT EXISTS to all create statements and run all several times until errors disappear.
If executed 2 times in the wrong order like this, second run will succeed without any error:
drop view if exists my_view;
create view if not exists my_view as select from table1; --fails first time, succeeds on second run
drop table if exists table1;
create table if not exists table1(id int);
If we specify ONLINE in the CREATE INDEX statement, the table isn't locked during creation of the index. Without ONLINE keyword it isn't possible to perform DML operations on the table. But is the SELECT statement possible on the table meanwhile? After reading the description of CREATE INDEX statement it still isn't clear to me.
I ask about this, because I wonder if it is similar to PostgreSQL or SQL Server:
In PostgreSQL writes on the table are not possible, but one can still read the table - see the CREATE INDEX doc > CONCURRENTLY parameter.
In SQL Server writes on the table are not possible, and additionally if we create a clustered index reads are also not possible - see the CREATE INDEX doc > ONLINE parameter.
Creating an index does NOT block other users from reading the table. In general, almost no Oracle DDL commands will prevent users from reading tables.
There are some DDL statements that can cause problems for readers. For example, if you TRUNCATE a table, other users who are in the middle of reading that table may get the error ORA-08103: Object No Longer Exists. But that's a very destructive change that we would expect to cause problems. I recently found a specific type of foreign key constraint that blocked reading the table, but that was likely a rare bug. I've caused a lot of production problems while adding objects, but so far I've never seen adding an index prevent users from reading the table.
I am trying to implement my SQLDeveloper DB into Oracle APEX. I cannot figure out how to get the PK's in my table to auto-increment starting from a certain value (i.e. 400001). I have tried making triggers and sequences but when I try to add a row using a form in APEX, my PK increments from 40 for some reason.
Here is my APEX form outcome
enter image description here
Here is how it inserts into SQL Developer
enter image description here
Basically, can someone describe to me how I can edit the existing trigger, or create a sequence, that would make application_id of a new entry auto-increment by 1.
Thanks!
Find max application_id:
select max(application_id) From your_Table;
Suppose it is 400010 (as screenshot suggests). Now recreate the sequence (presuming its name is seq_app):
drop sequence seq_app;
create sequence seq_app start with 400011 increment by 1 nocache;
Trigger is most probably OK, as you see values being inserted into the table.
Side note: sequences will be unique, but not necessarily gapless. CACHE (or NOCACHE) might affect that, but - for performance sake, you'd rather let Oracle cache sequence numbers (default is 20) which means that - if you don't use some of those cached numbers, they will be lost. I wouldn't worry, if I were you.
I having a problem executing an stored procedure that does multiple inserts
I am a copying 30 tables from a instance of a server to another by a DBLINK:
INSERT INTO table#dblink (column1)
SELECT column1
FROM table;
But it results in:
ORA-02291: integrity constraint (string.string) violated - parent key not found
There is only one commit at the end of the procedure.
The 4th table that I'm inserting, has an FK to the first one, and its no recognizing the inserts of the first one (I have tried with deferred constraints and same problem: ORA-02291).
The problem here is you are modifying data (DML) through db-link. This might be ill-managed by Oracle, and cause unexpected behavior. You should do it the other way around: instead of pushing data, drag data through this db-link, and do the inserts locally. Of course, you probably cannot technically do what you want on the destination database...
The solution you have is to deactivate the FK before your inserts, then activate the FK.
However, I am not sure this DDL is possible directly through db-link... You may need to create a procedure to deactivate the FKs on the destination database, and call it via db-link.
We have a table TRANSMISSIONS(ID, NAME) which behaves funny in the following ways:
The statement to add a foreign key in another table referencing TRANSMISSIONS.ID won't finish
The statement to add a column to TRANSMISSIONS won't finish
The statement to disable/drop a unique constraint won't finish
The statement to disable/drop a trigger won't finish
TRANSMISSION's primary key is ID, there is also a unique constraint on NAME - therefore there are indexes on ID and NAME. We also have a trigger which creates values for column ID using a sequence, so that INSERT statements do not need to provide a value for ID.
Besides TRANSMISSIONS, there are two more tables behaving like this. For other tables, the above-mentioned statements work fine.
The database is used in an application with Hibernate and due to an incorrect JPA configuration we produced high values for ID during a time. Note that we use the trigger only for "manual" INSERT statements and that Hibernate produces ID values itself, also using the sequence.
The first thought was that the problems were due to the high IDs but we have the problems also with tables that never had such high IDs.
Anyways we suspected that the indexes might be fragmented somehow and called ALTER INDEX TRANSMISSIONS_PK SHRINK SPACE COMPACT, which ran through but showed no effect.
Also, we wanted to call ALTER TABLE TRANSMISSIONS SHRINK SPACE COMPACT which didn't work because we needed to call first ALTER TABLE TRANSMISSIONS ENABLE ROW MOVEMENT which never finished.
We have another instance of the database which does not behave in such a funny way. So we think it might be that in the course of running the application the database got somehow into an inconsistent state.
Does someone have any suggestions what might have gone out of control/into an inconsitent state?
More hints:
There are no locks present on any objects in the database (according to information in v$lock and v$locked_object)
We tried all these statements in SQL Developer and also using SQLPlus (command-line tool).