I'm a SQL Server DBA currently getting up to speed on Oracle. I'm trying to create something very similar to sp_WhoIsActive for SQL Server but for Oracle without reinventing the wheel. Essentially all I'm doing is selecting some values from v$session and inserting them into a table (poor man's ASH/AWR).
It would seem that in Oracle 12.1, there's a bug when querying dictionary views where it can take forever due to bad parsing logic (Bug 22225899 : SLOW PARSE FOR COMPLEX QUERY). The work-around is to set a session parameter:
alter session set "_optimizer_squ_bottomup"=false;
In T-SQL, I could very easily execute a stored procedure in-session and set this variable at runtime. However in Oracle, it wouldn't seem thats the case.
Sample Code:
CREATE OR REPLACE PROCEDURE SP_DB_ACTIVITY
(
v_temp NUMBER :=1
) IS
BEGIN
alter session set "_optimizer_squ_bottomup"=false;
INSERT INTO SY_DB_ACTIVITY
SELECT
<fields>
FROM
v$session;
commit;
When I run this, I get the error:
"PLS-00103: Encountered symbol 'ALTER' when expecting one of the following..."
Right now, the only way I know how to do this is via a utility like SQL Plus that initiates an interactive user session. Can anyone give me some direction as to how Oracle handles this situation? I'd like to bundle this up into a SP or a Package and then call it from Oracle Scheduler.
Hre is a simple example how to execute alter session inside of the procedure:
CREATE PROCEDURE SP_DB_ACTIVITY IS
BEGIN
EXECUTE IMMEDIATE 'alter session set "_optimizer_squ_bottomup"=false';
END;
/
Here is the way you can combine that with your select and insert statement:
CREATE OR REPLACE PROCEDURE SP_DB_ACTIVITY
(v_temp IN number) AS
v_Id NUMBER;
BEGIN
EXECUTE IMMEDIATE 'alter session set "_optimizer_squ_bottomup"=false';
SELECT 1
INTO v_Id
FROM dual;
INSERT INTO SY_DB_ACTIVITY (id) VALUES(v_Id);
END SP_DB_ACTIVITY;
/
Here is a small DEMO where you can see what will procedure do when you call it and how you can call it. Also, in this example you are calling procedure with and IN parameter. So you can use that parameter for something and in the example above is the procedure without any parameters...
You can also, of course, insert into table directly:
CREATE OR REPLACE PROCEDURE SP_DB_ACTIVITY
(v_temp IN number) AS
v_Id NUMBER;
BEGIN
EXECUTE IMMEDIATE 'alter session set "_optimizer_squ_bottomup"=false';
INSERT INTO SY_DB_ACTIVITY(id)
select 1
from dual;
END SP_DB_ACTIVITY;
/
Related
I'm using PL/SQL Developer. I'm trying to get query results to excel via vba. Since query is so long, i decided to create table with the query results and then simply get the table results with vba. In order to create table via excel i needed to create procedure with dynamic sql. So this is what i tried so far (even this simple example doesn't work):
create or replace procedure d_x IS
str VARCHAR(81) = 'create table as select 1 as x from dual'
BEGIN
EXECUTE IMMEDIATE str;
END;
Procedure completes without error. But when i try to execute it to create table it throws an error.
Execute statement:
EXECUTE d_x;
The execute statement throws 'ORA-00900' Invalid sql statement error.
I'm kinda new to pl sql so i couldn't find a solution to this.
Any help would be appreciated, thanks.
Procedure you posted can't possibly execute without errors because it is invalid. When fixed, looks like this:
SQL> create or replace procedure d_x IS
2 str VARCHAR(81) := 'create table test as select 1 as x from dual';
3 BEGIN
4 EXECUTE IMMEDIATE str;
5 END;
6 /
Procedure created.
In tools that support execute, you can run it as:
SQL> execute d_x
PL/SQL procedure successfully completed.
SQL> select * from test;
X
----------
1
"Correct" way - which works anywhere - is to enclose it (the procedure) into begin-end block:
SQL> drop table test;
Table dropped.
SQL> begin
2 d_x;
3 end;
4 /
PL/SQL procedure successfully completed.
SQL>
I suggest you do that.
In PL/SQL Developer you can click on the procedure name and choose 'Test', which will generate a calling script as a Test window.
You can only use execute in a Command window, because it's a SQL*Plus command and not part of SQL or PL/SQL, and the Command window is a SQL*Plus emulator.
In a SQL window you could either use a complete PL/SQL block:
begin
d_x;
end
/
or use the SQL call command:
call d_x();
Note that call() requires brackets regardless of whether or not the procedure has any parameters.
The / character is useful as a separator when using PLSQL blocks in a SQL window where you have more than one statement, otherwise PL/SQ Developer won't know where one ends and the next starts.
A Test window can only have one statement and only a single PL/SQL block or SQL statement is allowed, so there is no / character at the end.
I'm doing something very similar to dnoeth's second comment on this question:
Insert Into table Teradata dynamic stored procedure SQL
I need to run it multiple times to loop the same insert statement but with different values for the "?" and I'm not sure how to go about that.
The dynamic value in my version is a date span. I can't run a massive insert without spooling out so I've broken the data into segments.
Thanks.
William,
As you are aware that you need to use cursor to iterate through each value you want to process.
For that purpose store dynamically created INSERT statement into a variable.
Final step: Use EXECUTE IMMEDIATE command to run insert statement stored in teradata variable
Here is the working sample that you may refer
REPLACE PROCEDURE td_user.sp_dynamic_insert( OUT proc_msg VARCHAR(5000) )
BEGIN
DECLARE lv_insert_txt VARCHAR(20000);
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
/* Error handling code if required */
END;
L0:
FOR insert_cursor AS select_list
CURSOR FOR
SELECT Col2
FROM test_1
DO
SET lv_insert_txt = 'INSERT INTO test_2(Col1,Col2) VALUES('||TRIM(insert_cursor.Col2)||','||TRIM(insert_cursor.Col2)||')';
EXECUTE IMMEDIATE lv_insert_txt;
END FOR L0;
SET proc_msg = 'Procedure completed successfully';
END;
I have some tables and views in my schema and I am trying to create a stored procedure that will take in 2 parameters (table_name, view_name) to Truncate a table and re-populate it from a view.
Here is the code I have for the procedure:
CREATE OR REPLACE
PROCEDURE PROC_NAME (TABLE_NAME IN VARCHAR2, VIEW_NAME IN VARCHAR2)
IS
BEGIN
EXECUTE IMMEDIATE 'TRUNCATE TABLE TABLE_NAME';
EXECUTE IMMEDIATE 'INSERT INTO TABLE_NAME
SELECT * FROM VIEW_NAME';
END;
/
Now when I run the following code:
BEGIN
PROC_NAME('SOME_TABLE', 'SOME_VIEW');
END;
/
I get the following error:
ORA-00942: table or view does not exist
ORA-06512: at "SCHEMA.PROC_NAME", line 4
ORA-06512: at line 2
00942. 00000 - "table or view does not exist"
What do you guys think is the issue?
Thanks in advance!
Try:
CREATE OR REPLACE
PROCEDURE PROC_NAME (TABLE_NAME IN VARCHAR2, VIEW_NAME IN VARCHAR2)
IS
BEGIN
EXECUTE IMMEDIATE 'TRUNCATE TABLE '||TABLE_NAME;
EXECUTE IMMEDIATE 'INSERT INTO '||TABLE_NAME||'
SELECT * FROM '||VIEW_NAME;
END;
/
Your basic problem is that you had passed the parameters correctly but had not used them in the procedure. The fix was to used the the concatenation operaterator || in the strings used by EXECUTE IMMEDIATE to combine the the parameters into the string being executed.
An additional option is to use DELETE FROM rather than TRUNCATE TABLE. When Oracle first implemented Materialised Views, which is a grown up version of what you are trying to achieve, they made the same mistake. TRUNCATE TABLE is very quick but in the Oracle implementation it is a DDL (Data Definition Language) statement which means it will complete with an implicit commit. Therefore, for a period of time until the INSERT completes (and is committed), your table will be empty. If Oracle thought it important enough to change their underlying technique, then you should consider doing the same.
If you do not change to the DELETE technique then you should adding a COMMIT at the end of your procedure. The use of TRUNCATE TABLE will guarantee the removal of the data is committed, so if your INSERT succeeds then you should also commit that statement.
My reference to Materialised Views is relevant as it is a potential a built-in replacement for what you are trying to write for yourself. The problem with it is that it has so many bells and whistles that it is difficult to find an article on how to use it in your simple use case. I would welcome a comment referencing such an article.
I have more than 40 tables in RATOR_MONITORING schema for which the table name is starting from 'TEMP_'. I want to delete data from all such tables at once in a single query instead of using delete statement for each and every table. I dont even want to generate statements. I can create anonymous block if required but dont know how to do that. I tried below query but its not working.
Delete from RATOR_MONITORING_CONFIGURATION.'%TEMP_';
If you want to delete all the rows, then better use TRUNCATE, it will reset the high watermark. But remember, truncate is a DDL statement, and thus there will be an implicit commit; With DELETE you can commit manually after validation.
Although, I would not do that in a production environment. If it is something you are doing in test environment to build test data, then you could (ab)use EXECUTE IMMEDIATE.
For example, execute the following anonymous block as RATOR_MONITORING user:
DECLARE
v_sql VARCHAR2(100);
BEGIN
FOR i IN
(SELECT table_name FROM user_tables where table_name like 'TEMP%'
)
LOOP
v_sql := 'TRUNCATE TABLE '||i.table_name;
EXECUTE immediate v_sql;
END LOOP;
END;
/
By the way, using a good text editor, it won't take more than a minute to build DELETE/TRUNCATE statements and do it in pure SQL.
I've created the following procedure
Create or replace procedure abcd
(
tab_name in USER_TABLES.table_name%type
)
is
begin
execute immediate
'select * from'||tab_name;
end abcd;
The procedure gets compiled.
I am trying to get the output using the following
select abcd('Table') from dual ;
I am new to dynamic SQL and this does not seem to work for me. I keep getting the error
[Error] Execution (44: 8): ORA-00904: "ABCD": invalid identifier
Can someone please help ?
Regards,
Kshitij
You're missing a space before your table name:
create or replace procedure abcd (tab_name in USER_TABLES.table_name%type )
is
begin
execute immediate 'select * from '||tab_name;
end abcd;
This won't work because you're trying to call it as a function, not a procedure:
select abcd('Table') from dual ;
Your second attempt should now work:
exec abcd('Table');
... but will now get a different error. In PL/SQL you have to select into something. In this case you probably want to open a cursor with the dynamic string and do something with the results. Not really sure what your end goal is though.
You should also read up about SQL injection while you learn about dynamic SQL.
you cannot perform a select on a procedure, a function will work only if single record return.
use
begin
abcd();
end;
or use
execute keyword
ALSO use a space after from in query
It will not work.
When you invoke EXECUTE IMMEDIATE the sql statement is send to SQL engine. No results are passed back to the PL/SQL.
Writing "SELECT * FROM a_table" is not that hard and much safer.