ORA - 04020: deadlock detected while trying to lock object - oracle

Getting an ORA-04020: deadlock detected while trying to lock object and I believe the source of the error could be these statements:
v_sql := 'DELETE FROM ' || in_table_name || ' SUBPARTITION (' || v_subpart_name || ')';
EXECUTE IMMEDIATE v_sql;
v_sql := 'ALTER TABLE ' || in_table_name || ' TRUNCATE SUBPARTITION ' || v_subpart_name;
EXECUTE IMMEDIATE v_sql;
Any ideas on how to resolve this issue? Could it be the ALTER statement is throwing the error since the DELETE is right before it? Not sure, I thought the ALTER would execute only once the DELETE if finished. Or could it be the procedure doesn't wait for the ALTER to complete before exiting and re-executing?

if your already doing TRUNCATE SUBPARTITION then why you need to delete . TRUNCATE would be much efficient way to delete data from table.
other wise you have to do commit after delete , then only truncate is allowed.
Regards
Ramki

Related

Oracle: Invalid ALTER command in execute immediate

In the procedure, in the ALTER command, I need to dynamically substitute the name of the trigger that needs to be activated.
declare
v_trg_name varchar2(25) := 'article_comment_audit';
begin
execute immediate 'ALTER TRIGGER' || v_trg_name || 'ENABLE';
end;
I try to run this code, but it returns an error ORA-00940 invalid ALTER command
Please tell me what is the problem?
You'll get 'ALTER TRIGGERarticle_comment_auditENABLE'.
Insert Blanks:
'ALTER TRIGGER ' || v_trg_name || ' ENABLE';
in order to get 'ALTER TRIGGER article_comment_audit ENABLE'.

Truncate and drop storage in multiple tables in oracle

I wanna action a truncate and drop storage in multiple tables in oracle.
I am using the pl/SQL below :
BEGIN
FOR i IN (select('LOG_'||X.TABLE_ID) AS LogTables from LOGFILE X)
LOOP
EXECUTE IMMEDIATE 'TRUNCATE TABLE ' || i.LogTables ;
END LOOP;
END;
My code works perfectly but i wanna add the 'DROP STORAGE' clause.
How shall i Proceed ?
I found the answer :
BEGIN
FOR i IN (select('SDE_LOGPOOL_'||X.TABLE_ID) AS LogPoolTables from SDE_LOGFILE_POOL X)
LOOP
EXECUTE IMMEDIATE 'TRUNCATE TABLE ' || i.LogPoolTables || ' DROP STORAGE' ;
END LOOP;
END;

PL/SQL Triggers with dynamic sql

I want to create ddl trigger(on create) which will create a dml trigger
But i have error:
ORA-06512: на line 8
00604. 00000 - "error occurred at recursive SQL level %s"
*Cause: An error occurred while processing a recursive SQL statement
(a statement applying to internal dictionary tables).
*Action: If the situation described in the next error on the stack
can be corrected, do so; otherwise contact Oracle Support.
CREATE OR REPLACE TRIGGER test_ddl
after CREATE ON SCHEMA
DECLARE
user_col VARCHAR(5) := 'user_';
time_col VARCHAR(5) := 'time_';
BEGIN
IF ora_dict_obj_type = 'TABLE'
THEN
EXECUTE IMMEDIATE 'alter table ' || ora_dict_obj_name || ' add(' || user_col || ' varchar(20), '|| time_col ||' timestamp)'||'';
EXECUTE IMMEDIATE 'CREATE OR REPLACE TRIGGER add_user_time BEFORE INSERT OR UPDATE ON test_tab FOR EACH ROW BEGIN ' || ':' || 'new.time_ := sysdate; END';
END IF;
END;
/
DROP TABLE test_tab PURGE;
/
CREATE TABLE test_tab(ID NUMBER);
At the very least, I expect you want new.time_ to be :new.time_
You are missing a semicolon after the END.
Replace this
EXECUTE IMMEDIATE 'CREATE OR REPLACE TRIGGER add_user_time BEFORE INSERT OR UPDATE ON test_tab FOR EACH ROW BEGIN ' || ':' || 'new.time_ := sysdate; END';
with that
EXECUTE IMMEDIATE 'CREATE OR REPLACE TRIGGER add_user_time BEFORE INSERT OR UPDATE ON test_tab FOR EACH ROW BEGIN ' || ':' || 'new.time_ := sysdate; END;';
Full error messages are:
ORA-00604: error occurred at recursive SQL level 1
ORA-24344: success with compilation error
ORA-06512: at line 8
Important part was:
ORA-24344: success with compilation error
The source code should read:
CREATE OR REPLACE TRIGGER test_ddl
after CREATE ON SCHEMA
DECLARE
user_col VARCHAR(5) := 'user_';
time_col VARCHAR(5) := 'time_';
BEGIN
IF ora_dict_obj_type = 'TABLE'
THEN
EXECUTE IMMEDIATE 'alter table ' || ora_dict_obj_name || ' add(' || user_col || ' varchar(20), '|| time_col ||' timestamp)'||'';
EXECUTE IMMEDIATE 'CREATE OR REPLACE TRIGGER add_user_time BEFORE INSERT OR UPDATE ON test_tab FOR EACH ROW BEGIN ' || ':' || 'new.time_ := sysdate; END;';
END IF;
END;
/
DROP TABLE test_tab PURGE;
/
CREATE TABLE test_tab(ID NUMBER);
Just as an explanation: I have put some log messages to see where it exactly fails. Then you can see that the trigger is recursively called upon the CREATE OR REPLACE TRIGGER but with an ora_dict_obj_type = TRIGGER

Create Oracle users in a loop with default tablespace

I try to execute this but it gives an error at the default tablespace. I want to give a default tablespace to the users I create but how?
BEGIN
FOR USERNAME IN (SELECT studentname from students)
LOOP
EXECUTE IMMEDIATE 'CREATE USER ' || USERNAME.studentname || ' IDENTIFIED BY ' || USERNAME.studentname;
EXECUTE IMMEDIATE 'DEFAULT TABLESPACE "USERS"';
EXECUTE IMMEDIATE 'TEMPORARY TABLESPACE "TEMP"';
EXECUTE IMMEDIATE 'GRANT STUDENT TO ' || USERNAME.studentname ;
END LOOP;
END;
Error report - ORA-00900: invalid SQL statement ORA-06512: at line 5 00900. 00000 - "invalid SQL
You need to combine the first three statements into one and add in appropriate spaces. You don't need the double-quotes around the tablespace names since you're using case-insensitive identifiers.
BEGIN
FOR USERNAME IN (SELECT studentname from students)
LOOP
EXECUTE IMMEDIATE 'CREATE USER ' || USERNAME.studentname || ' IDENTIFIED BY ' || USERNAME.studentname ||
' DEFAULT TABLESPACE USERS
TEMPORARY TABLESPACE TEMP';
EXECUTE IMMEDIATE 'GRANT UNLIMITED TABLESPACE TO ' || USERNAME.studentname;
EXECUTE IMMEDIATE 'GRANT STUDENT TO ' || USERNAME.studentname ;
END LOOP;
END;
Personally, I'd always generate a string with the SQL statement and pass that string to EXECUTE IMMEDIATE. That makes it easy to do things like log the SQL statements that are executed or to log which statement failed. That's going to make debugging far easier.

When does user_tab_columns get updated?

In another question I tried to create a hist table, which keeps a log from the given table. With the answers in that question, I tried to create something new.
Since it is not possible to create a system trigger on tables or views, I created a DDL trigger like this:
create or replace trigger ident_hist_trig after alter on schema
declare
v_table varchar2(30);
begin
select upper(ora_dict_obj_name) into v_table from dual;
if (v_table = 'Z_IDENT') then
prc_create_hist_tabel('z_ident_hist', 'z_ident');
elsif (v_table = 'D_IDENT') then
prc_create_hist_tabel('d_ident_hist', 'd_ident');
elsif (v_table = 'X_IDENT') then
prc_create_hist_tabel('x_ident_hist', 'x_ident');
else
null;
end if;
end;
/
The procedure prc_create_hist_tabel looks like this:
create or replace procedure prc_create_hist_tabel(p_naam_hist_tabel in varchar2, p_naam_tabel in varchar2) is
cursor c is
select 'alter table ' || p_naam_hist_tabel || ' add ' || column_name || ' ' || data_type || case when data_type = 'DATE' then null else '(' || data_length || ')' end lijn
from user_tab_columns
where TABLE_NAME = upper(p_naam_tabel)
and column_name not in (select column_name from user_tab_columns where table_name = upper(p_naam_hist_tabel));
v_dummy number(1);
cursor trig is
select column_name || ',' kolom, ':old.' || column_name || ',' old
from user_tab_columns
where table_name = upper(p_naam_tabel);
v_trigger_sql varchar2(32767);
begin
begin
select 1 into v_dummy
from user_tab_columns
where TABLE_NAME = upper(p_naam_hist_tabel)
group by 1;
exception when no_data_found then
execute immediate 'create table ' || p_naam_hist_tabel || ' (wijziger varchar2(60) default user, wijzigdatum date default sysdate, constraint pk_' || p_naam_hist_tabel || ' primary key (wijziger, wijzigdatum))';
end;
dbms_output.put_line('BBB');
for i in c
loop
begin
dbms_output.put_line(i.lijn);
execute immediate i.lijn;
exception when others then
dbms_output.put_line(i.lijn);
end;
end loop;
v_trigger_sql := 'create or replace trigger ' || p_naam_tabel || '_hist_trig after update on ' || p_naam_tabel || ' for each row begin insert into ' || p_naam_hist_tabel || ' (';
for v_lijn in trig
loop
v_trigger_sql := v_trigger_sql || v_lijn.kolom;
end loop;
v_trigger_sql := substr(v_trigger_sql, 1, length(v_trigger_sql) - 1);
v_trigger_sql := v_trigger_sql || ') values (';
for v_lijn in trig
loop
v_trigger_sql := v_trigger_sql || v_lijn.old;
end loop;
v_trigger_sql := substr(v_trigger_sql, 1, length(v_trigger_sql) - 1);
v_trigger_sql := v_trigger_sql || '); end;';
execute immediate v_trigger_sql;
end;
/
In short what that function does, is maintain the history table. If it doesn't exist, it will create one, and if it exists, it will add the new columns to it. The procedure also creates a new trigger which will write the old values into the history table after update.
But when I alter one of the tables x_ident, z_ident or d_ident, the cursor c will return nothing (I can check that with the print when I loop through it). Although when execute the select after I altered my table, then I do get results.
The results I get from altering the table d_ident are these:
BBB
d_ident: Table altered.
But I guess it should be the other way around, I think that the procedure prc_create_hist_tabel is executed before the alter table actually goes off, and I guess I should get something like this:
d_ident: Table altered.
BBB
Any help would be apreciated. I tried to create a trigger on insert on user_tab_columns, but that gave me ORA-25001: cannot create this trigger type on views.
I tried with a sleep command as well, but that didn't work either.
This won't work. Even if you were able to get the column that is being added to the table in your trigger, if you tried to actually do DDL in a trigger, you'd get an error that DDL isn't allowed in a trigger.
I'd expect that the right way to approach this would be to make the call to prc_create_hist_tabel as part of your promotion scripts. Reasonable systems don't add columns to tables willy-nilly. The DDL is part of a promotion that exists in source control and gets deployed after testing. If your promotion scripts failed to modify the history table, you'd find out during testing that you missed a step and the change would never go to production. Having changes happen automatically means that they're not in change control which makes it more difficult to do a build from change control.
If you are determined to do this automatically, your trigger would need to submit a job, realistically using dbms_job not the newer dbms_scheduler, that calls the procedure. That job would run after the transaction the DDL trigger is a part of committed. At that point, the column would be visible in dba_tab_columns. And your job is free to do DDL.

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