ORA-00054 error in SQL

Question

I am getting the above error :

ORA-00054 error in SQL "Resource busy and acquire with NOWAT specified or timeout expired"

When i try and run the following command:

CREATE TABLE CONFERENCESESSION (
SESSIONID CHAR(4) NOT NULL,
BUILDINGNO CHAR(2),
ROOMNO CHAR(2) NOT NULL,
SPEAKERID CHAR(2),
SESSIONDATE DATE,
SESSIONPRICE NUMBER(4,2),
CONSTRAINT SESSIONID_PK PRIMARY KEY(SESSIONID),
CONSTRAINT BUILDINGNO_FK1 FOREIGN KEY (BUILDINGNO) REFERENCES BUILDING(BUILDINGNO),
CONSTRAINT ROOMNO_FK2 FOREIGN KEY (ROOMNO,BUILDINGNO) REFERENCES ROOM(ROOMNO,BUILDINGNO),
CONSTRAINT SPEAKERID_FK3 FOREIGN KEY (SPEAKERID) REFERENCES SPEAKER(SPEAKERID)
);

I am unsure how to find what is using the object.

I am using Oracle SQL developer for a school assignment.

Answer 1

That error is normally caused by locking, try breaking up you create table query, like:

CREATE TABLE CONFERENCESESSION (
SESSIONID CHAR(4) NOT NULL,
BUILDINGNO CHAR(2),
ROOMNO CHAR(2) NOT NULL,
SPEAKERID CHAR(2),
SESSIONDATE DATE,
SESSIONPRICE NUMBER(4,2)
)
GO

ALTER TABLE CONFERENCESESSION ADD CONSTRAINT SESSIONID_PK PRIMARY KEY(SESSIONID)
GO
ALTER TABLE CONFERENCESESSION ADD CONSTRAINT BUILDINGNO_FK1 FOREIGN KEY (BUILDINGNO) REFERENCES BUILDING(BUILDINGNO)
GO
ALTER TABLE CONFERENCESESSION ADD CONSTRAINT ROOMNO_FK2 FOREIGN KEY (ROOMNO,BUILDINGNO) REFERENCES ROOM(ROOMNO,BUILDINGNO)
GO
ALTER TABLE CONFERENCESESSION ADD CONSTRAINT SPEAKERID_FK3 FOREIGN KEY (SPEAKERID) REFERENCES SPEAKER(SPEAKERID)
GO

Run each batch individually and you'll be able to isolate the part that is causing the error

Answer 2

you may use this query to detect who's locking your table:

select distinct s.inst_id, s.sid, s.serial#, s.module, s.client_info, s.username, s.status, s.osuser, o.object_name
from gv$session s, gv$locked_object l, dba_objects o 
where l.object_id = o.object_id 
  and l.session_id = s.sid 
  and l.inst_id = s.inst_id
  and lower(o.object_name) like lower('%'||'&i_table_name'||'%') 
--and lower(s.module) like lower('%'||'&i_modul_name'||'%')  
--and s.username = upper('&i_schema_name')
order by o.object_name

if you have db privileges.

Answer 3

已修正，我可以通过我的uni网站删除当前会话。