Alter table DDL does a FTS

We are trying to modify some columns from BYTE semantics to CHAR semantics in a UTF8 database and noticed that for some tables the ALTER TABLE ... modify (col varchar2(nn CHAR)) statement is very fast and for others it does a full table scan and takes a very long time. Verified this using sql_trace/tkprof and looking at the trace file.
What determines whether the data in the table is scanned vs a quick dictionary update? It also doesn't appear to make a difference whether the column(s) being modified are part of a primary/unique key constraint.
Comments? Thanks

Yes, the tables that were fast is much smaller than the ones that took a long time but that might have been a co-incidence since, as I said, when I looked at the trace file, the fast one did not do many LIOs at all.
I am just trying to determine how does this ALTER TABLE ... MODIFY command works and if it is possible to speed it up for tables containing a lot of data. I always thought that operations like adding a new column, expanding a column were quick dictionary updates regardless of the number of rows in the table.
Thanks
Fastcall     count       cpu    elapsed       disk      query    current        rows
Parse        1      0.00       0.00          0          0          0           0
Execute      1      0.08       0.13          2          6         19           0
Fetch        0      0.00       0.00          0          0          0           0
total        2      0.08       0.14          2          6         19           0Slow (cancelled it after a few seconds, the table is very big)
call     count       cpu    elapsed       disk      query    current        rows
Parse        1      0.00       0.02          0          0          0           0
Execute      1      5.12      13.35      16127      16068          0           0
Fetch        0      0.00       0.00          0          0          0           0
total        2      5.12      13.37      16127      16068          0           0

Similar Messages

Generate DDL - change is a new column and I want to generate a alter table

Morning all,
I have searched and looked all over the data modeler and I cannot find this option ... yet I did find it easily in Designer.
I hope you can help me.
SQL Developer Data Modeler v3.0.0.665.
I have added a new column to a table and when I generate the DDL I would like it to be an alter table add column rather than a create table.
This feature is in Designer so I would think it would be in data modeler.
Just incase my description is not clear here are the high level steps so it is clear.
1. create the logical model
2. create the relational from the logical.
3. create the physical from the relational.
4. generate DDL and run in database. At this point I go to production with my system and all is well.
5. At this point we have an enhancement request. For the model it will be a new column in a table.
6. update logical model.
7. update relational from logical
8. update physical from relational
9. generate DDL. Here I would like to have the generate be aware the it needs only to generate an alter table add column and not create the table.
This is something I do alot as all my models are in production. I cannot find how to do this step of getting data modeler to generate the alter.
Designer does this exceptionally well.
Quite often it is more than a single column. The changes can be many and made over time and at the time of generating the DDL you may not recall every single change you made. To have the tool discover those changes for you and generate the appropriate DDL is a feature I regard as very high.
I hope this is clear and you can help me.
Cheers
Chris ....

Hi Chris,
you need to compare your model against database - import from database into same relational model and use "swap target" option - in this case "alter statements" against database will be generated.
You can look at demonstrations here http://www.oracle.com/technetwork/developer-tools/datamodeler/demonstrations-224554.html
Probably this particular one will be most helpful http://download.oracle.com/otn_hosted_doc/sqldev/importddl/importddl.html
Soon or later your changes will require table to be recreated and you'll need to backup your data - you can consider usage of "Advanced DDL" option - script will be generated that will unload the content of your table (including LOBs) to file system accessible from database and restore it after changes. Well don't try it directly on production system :).
Philip

DDL failure (eg. ALTER TABLE) - will it commit or not?

Trying to fathom out whether a failing DDL statement still does an implicit COMMIT.
I disable a constraint. Then manipulating the data hoping that all is referentially correct. I am then trying to reinstate (ENABLE) the constraint, which in my case is an FK. What happens if this fails, for instance because an ORA-02298 error is yielded as a reaction upon ENABLEing the constraint? Are any other data in the session committed or not?
My initial idea was that it would fail to commit, but I can't be so sure now. Does anybody have any experience in this matter?
Thanks!

DDl issues two implicit commits, one before one after. So even if the statement fails any prior DML if the transaction will have been committed.
Simple demo: in session 1 let's create and populate a table
SQL1> CREATE TABLE my_t1 (col1 number)
2 /
Table created.
SQL1> INSERT INTO my_t1 VALUES (1)
2 /
1 row created.
SQL1> r
1* INSERT INTO my_t1 VALUES (1)
1 row created.In session 2 our table seems to be empty...
SQL2> SELECT * FROM my_t1
2 /
no rows selected
SQL2>Back in session 1 we issue some DDL which is bound to fail...
SQL1> ALTER TABLE my_t1 ADD CONSTRAINT my_pk PRIMARY KEY (col1)
2 /
ALTER TABLE my_t1 ADD CONSTRAINT my_pk PRIMARY KEY (col1)
ERROR at line 1:
ORA-02437: cannot validate (A.MY_PK) - primary key violated
SQL1>Now in session 2 that table is populated...
SQL2> SELECT * FROM my_t1
2 /
      COL1
         1
         1
SQL2> Quod erat demonstrandum
Cheers, APC

ALTER TABLE command with owner does not work

I performed the following statement in a SQLplus script where the variables were filled some lines before:
alter table '&ownername||'.'||&tablename' move online tablespace '&tablespacename';
However this does not work. I am getting:
ERROR at line 1:
ORA-00903: invalid table name
The variables are replace correctly by SQLplus and everything owner, table, tablespace exist.
Can I (as SYSDBA) not alter the table of another user?
Peter

Solomon Yakobson wrote:
EdStevens wrote:
Ok, you removed the mis-placed quotes, but why the double "." ??
If you wish to append characters immediately after a substitution variable, use a <font color=red size=3>period</font> to separate the variable from the character.
SY.Ah, I had simply never done it that way nor seen it done that way.

Replicating DDL, but only for ALTER TABLE/CREATE TABLE

We're looking to use Streams to replicate our database, for Warehouse use. We're not looking to use any ETL, but rather copy the table structures & data over identically as they appear in the source database. We'll add indexes in a custom step. Otherwise, though, we don't need TRIGGERs, PROCs, VIEWs etc.
Is this possible in Streams? Probably asking if it's possible is the wrong question ... Is this something that is normally done, or does it bring with it a significant amount of complexity, plus some extra things to note (like, "..don't forget TRUNCATE also...")
Thanks,
Chuck

Sorry to bump this one ...
So, if our intent is to copy over all tables in a specified list of shemas, in their current form, and then we wanted to capture:
INSERTs
UPDATEs
DELETEs
TRUNCATE TABLE
ALTER TABLE (but excluding anything related to CONSTRAINTS)
(... I'm thinking that's all we'd need to keep a copy of the main db in the warehouse, without a DBA having to "retouch" the warehouse to keep it in sync ...)
Would that be considered a complicated configuration? The ALTER TABLE piece sounds picky enough, that it could be a headache ... but I'm thinking the Oracle reps were being pushy about the amount effort needed to set this environment up.
--=Chuck

High wait on Library Cache Lock while doing ALTER TABLE EXCHANGE PARTITION

We are observing a very high wait time on "Library cache lock" while performing Exchange partition.
Here we go
ALTER TABLE PSALESREG EXCHANGE PARTITION P123
WITH TABLE PBKPSALESREF WITHOUT VALIDATION
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 1 0.11 *6684.73* 2 9 2 0
Fetch 0 0.00 0.00 0 0 0 0
total 2 0.11 6684.73 2 9 2 0
Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
library cache lock 2274 3.12 *6681.32*
Is it a bug? is anyone there who experienced the same issue?
Rgds

Maurice Muller wrote:
Hi,
As far as I remember a exchange partition can only be done when no other query is accessing the table.
So you should check if any other queries are executed against the table PSALESREG while you do the exchange partition. Maurice,
queries won't block the exchange operation but continue to read from the "original", exchanged segment; this "cross-DDL" read consistency is a feature that has been introduced a long time ago.
But any kind of (long-running) DML should effectively prevent the exchange operation. Still I would assume that this shouldn't show up as "library cache lock", but you would get an "ORA-00054: resource busy" error.
Regards,
Randolf
Oracle related stuff blog:
http://oracle-randolf.blogspot.com/
SQLTools++ for Oracle (Open source Oracle GUI for Windows):
http://www.sqltools-plusplus.org:7676/
http://sourceforge.net/projects/sqlt-pp/

Can't import DDL file that has alter table rename constraint

Hi:
Version 3.1.0.691 on Windows 7 Enterprise 64-bit SP1
I'm trying to import a DDL file with syntax similar to what's below. The <name> notes that I've replaced the actual names for obfuscation purposes.; the real names are in the script.
ALTER TABLE <name>
RENAME CONSTRAINT SYS_C0041150
TO <name2>_CK;
ALTER TABLE <name>
RENAME CONSTRAINT AVCON_1281559518_ACTIV_022
TO <name2>_CK;
I get the following error:
Oracle SQL Developer Data Modeler 3.1.0.691
Oracle SQL Developer Data Modeler Import Log
Date and Time: 2012-01-13 16:29:05 PST
Design Name: <name>
RDBMS : Oracle Database 11g
          All Statements:           819
          Imported Statements:      0
          Failed Statements:           0
          Not Recognized Statements:      819
<<<<< Not Recognized >>>>>
ALTER TABLE <name>
RENAME CONSTRAINT SYS_<name>
TO <name2>_CK
ALTER TABLE <name>
RENAME CONSTRAINT AVCON_1281559518_QVI_A_000
TO <name2>_CK
Thanks for any help you can provide.
Doc

Hi:
The file was indeed comprised of just alter statements. As a test, I trimmed the file down to just one alter statement:
ALTER TABLE <name> RENAME CONSTRAINT SYS_C0041413 TO <name2>_CK;
The output file contained exactly the following, where the <<BEGIN OF FILE>> and <<END OF FILE>> were simply added here for clarity. There was no section called
<<<<< ERRORS >>>>> and the ddl file contained no create table statements.
<<BEGIN OF FILE>>
Oracle SQL Developer Data Modeler 3.1.0.691
Oracle SQL Developer Data Modeler Import Log
Date and Time: 2012-01-16 10:16:42 PST
Design Name: <name>
RDBMS : Oracle Database 11g
          All Statements:           1
          Imported Statements:      0
          Failed Statements:           0
          Not Recognized Statements:      1
<<<<< Not Recognized >>>>>
ALTER TABLE <name> RENAME CONSTRAINT SYS_C0041413 TO <name2>_CK
<<END OF FILE>>
Other info.
When I do an model import, none of the existing check constraint names get captured. Also, if I add names afterwards to two separates models via DM and then compare them. The output DDL shows a drop of the target constraint referencing its name, but the recreation of the not null constraint doesnt reference the source constraint name set for it manually in DM. Here's the example I did and the output ddl.
ALTER TABLE <name>
DROP CONSTRAINT SYS_C0041413
ALTER TABLE <name>
MODIFY ( <column_name> NOT NULL )
That last line should have read as follows due to the constraint_name I added for it in DM.
ALTER TABLE <name>
MODIFY (<column_name> CONSTRAINT <name2>_CK NOT NULL);
In the example directly above, <name2>_CK is the name I explicity set via DM and would have expected the compare to have used to recreated the constraint since it referenced the target constraint name when it constructed the drop constraint syntax.
I believe at least one bug is involved here, most likely two.
The first bug is that model imports are not capturing not null check constraint names.
The second bug is that the source constraint name is not being used when generating the ddl necessary to change the not null constraint name in the target model.
All of this is assuming that I haven't just goofed and forgotten to check a box somewhere telling it to do what I've been talking about here. :-)
Doc

Problem with alter table in execute immediate

We have PL/SQL scripts which modify the data structure, add data etc to en existing database. These scripts basically ensure that the db is compatible with what the software expects.
The reason for doing it in PL/SQL rather than SQL script is A) The scripts are launched using GUI so that they are more user friendly. sqlplus is launched as a background process which executes these scripts. All the scripts have EXIT FAILURE WHENEVER SQLERROR as first line to ensure that the control does not hang in the sqlplus background process.
Going from one version to other, we have added a few tables to the database and also modified a few tables. since (i think) DDL is not allowed in PL/SQL block, we had to resort to putting them in EXECUTE IMMEDIATE enclosures.
Now for the real question,
If I create a table using EXECUTE IMMEDIATE clause, I can immediately have insert as a next statement to insert data in this table. but, if I alter the table and add a column to the existing table, I cannot immediately add data to that column, it throws an error saying 'invalid identifier'
At code level, the following is allowed :
EXECUTE IMMEDIATE 'CREATE TABLE SP_TEST_TABLE
                         ID     NUMBER,
                         NAME     Varchar2(40)
INSERT INTO SP_TEST_TABLE(ID, NAME) Values(1, 'SP');
but I get error for the following :
EXECUTE IMMEDIATE 'ALTER TABLE SP_TEST_TWO ADD
                    ANOTHER_COLUMN     number
UPDATE     SP_TEST_TWO SET          ANOTHER_COLUMN = 1;
In this case, it says ANOTHER_COLUMN invalid identifier
Does anybody know why?
any workaround will be greatly appreciated.
--SP

Friends,
Thanks to all of you for your help. The spelling mistakes might have occurred becuase i changed the actual script to something 'short and complete' to show the problem.
I could solve the problem by having more than one PL/SQL block within my file. something like :
BEGIN
--alter table statements here
END;
BEGIN
--insert the values in column here.
END;
I am still not sure why the error is presented only on alter table statement and not for create table statement. Probably somebody with the knowledge of oracle internals will be able to throw more light on it. I am trying to get the naswers, if I get the answer, I'll surely post it here.
Regards,
--Saurabh

Alter Table Problem/Hang

I'm using oracle9i on windows 2000/NT.
All the DDL Commands(alter table,drop table etc..) result in hanging of the session.
On restarting the oracle instance the command starts working. But only for sometime. We reinstalled oracle for 2-3 time and on different servers. But the problem persists. What could be reason/solution for this.

No, you cannot avoid the recompiles. An ALTER TABLE changes the structure of the table and all dependent objects have to be recompiled -- the dependent objects
are set to status INVALID. The RDBMS does do an implicit
compile when an INVALID View/Package/Procedure is invoked but, occassionally, with a long list of dependencies and cross-dependencies, it may fail to compile an object.
Use DBA_DEPENDENCIES to identify dependencies.
Hemant

Using dbms_metadata.get_ddl to capture the alter table

Hi there,
I know you can capture table ddl using dbms_metadata.get_ddl. However, I want to capture all the changes after the table got created. If you created a table then add one or more columns. I just want to capture the change as the new columns added.
Here's an example.
Create table test (id number, name varchar2(20);
then
alter table test add (type varchar2(40);
I want to capture the syntax "alter table test add (type varchar(40)". Is this possible?
Thanks

I dont belive you could easily use dbma_metadata to do this... but you can use a database or schema level trigger e.g. :
create or replace trigger test.test_trigger
AFTER ALTER
ON DATABASE
DECLARE
sql_text ora_name_list_t;
v_stmt VARCHAR2(2000);
n number;
BEGIN
n := ora_sql_txt(sql_text);
FOR i IN 1..n
LOOP
v_stmt := v_stmt || sql_text(i);
END LOOP;
INSERT INTO test.test_table2
VALUES
(v_stmt);
END;
This will capture all alter commands fired at the database... so you would then need to filter them using the System-Defined Event Attributes see
http://download-uk.oracle.com/docs/cd/B19306_01/appdev.102/b14251/adfns_triggers.htm#i1006211

Multiple Alter Table Statements in one batch

Hi Team,
We have in one of our upcoming release two columns being added to a table that has over 20 million records and 14 indexes.
We needed to add two columns to the table both not null (bit). Because it was taking a while to add the columns, we thought that putting these two alter statements in one batch would speed up the operation significantly but to my surprise it did not.
Conclusion from my test: individual alter statements or batch alter statements take the same time
Here are me test and results - table Order1 and Order2 are exactly the same structure and data.
Test case 1:
===================
ALTER TABLE Order1
ADD OR_N BIT DEFAULT 0 NOT NULL
go
ALTER TABLE AccountTradeConfirmation_Alter1
ADD OR_S BIT DEFAULT 0 NOT NULL
Go
Elapsed Time: 2 hrs
             Mar 18 2015 5:56PM
(1 row affected)
Non-clustered index (index id = 3) is being rebuilt.
Non-clustered index (index id = 4) is being rebuilt.
Non-clustered index (index id = 5) is being rebuilt.
Non-clustered index (index id = 6) is being rebuilt.
Non-clustered index (index id = 7) is being rebuilt.
Non-clustered index (index id = 8) is being rebuilt.
Non-clustered index (index id = 9) is being rebuilt.
Non-clustered index (index id = 10) is being rebuilt.
Non-clustered index (index id = 11) is being rebuilt.
Non-clustered index (index id = 12) is being rebuilt.
Non-clustered index (index id = 13) is being rebuilt.
Non-clustered index (index id = 14) is being rebuilt.
(21777920 rows affected)
Non-clustered index (index id = 3) is being rebuilt.
Non-clustered index (index id = 4) is being rebuilt.
Non-clustered index (index id = 5) is being rebuilt.
Non-clustered index (index id = 6) is being rebuilt.
Non-clustered index (index id = 7) is being rebuilt.
Non-clustered index (index id = 8) is being rebuilt.
Non-clustered index (index id = 9) is being rebuilt.
Non-clustered index (index id = 10) is being rebuilt.
Non-clustered index (index id = 11) is being rebuilt.
Non-clustered index (index id = 12) is being rebuilt.
Non-clustered index (index id = 13) is being rebuilt.
Non-clustered index (index id = 14) is being rebuilt.
(21777920 rows affected)
             Mar 18 2015 7:52PM
Test case 2:
===================
ALTER TABLE Order2
ADD OR_N BIT DEFAULT 0 NOT NULL, OR_S BIT DEFAULT 0 NOT NULL
go
2 hrs elapsed time
             Mar 20 2015 11:10AM
(1 row affected)
Non-clustered index (index id = 3) is being rebuilt.
Non-clustered index (index id = 4) is being rebuilt.
Non-clustered index (index id = 5) is being rebuilt.
Non-clustered index (index id = 6) is being rebuilt.
Non-clustered index (index id = 7) is being rebuilt.
Non-clustered index (index id = 8) is being rebuilt.
Non-clustered index (index id = 9) is being rebuilt.
Non-clustered index (index id = 10) is being rebuilt.
Non-clustered index (index id = 11) is being rebuilt.
Non-clustered index (index id = 12) is being rebuilt.
Non-clustered index (index id = 13) is being rebuilt.
Non-clustered index (index id = 14) is being rebuilt.
(21777920 rows affected)
             Mar 20 2015 1:12PM

Hi Kiran,
I have read your response a few times and I was not able to understand your angle. I assume based on the results of my test that Sybase does the following in processing the alter statements
ALTER TABLE Order2
ADD OR_N BIT DEFAULT 0 NOT NULL, OR_S BIT DEFAULT 0 NOT NULL
go
process alter ADD OR_N BIT
-- > make copy of table
---> alter original table
--> put data back in
process alterOR_S BIT
-- > make copy of table
---> alter original table
--> put data back in
rebuild index
my expectation was that it would make a copy of the table only once and process the two alter statements. Also when doing the alter separately (test1) it rebuilt the index twice, however using the batch the index was rebuilt once (at least only one message displayed).
Regards.

In which tables sap does not add partitions to partitioned tablespaces

Hi Team,
I would like to know in which tables sap does not add partitions to partitioned tablespaces in a BW 7.00 system on aix db2. any idea?
DB2 version is 8.1.5
Thanks,
Asad
Message was edited by: Asad S Zafer

The documentation you quote says
Local and global indexes associated with the range-partitioned table remain usable.When you added a partition, the indexes remained usable, just as it said they would:
when checked for the status of the indexes, I can still see them as USABLE.so I'm not sure what the issue is.
btw I'm not sure what you mean by
creating a table and adding local and global partition using the ALTER CommandDid you mean the ALTER TABLE command? What are "local and global partitions" and how did you add them?

What privs r required to run Alter table truncate partition update indexes?

I rebuilt the indexes on the table. Know my problem is that when I truncate a partition on the table the unique index whic consist of the primary key fields becomes unusable which causes my to have to rebuild it after each truncate. I tried to runm the following statement from the master schema on but get
an insufficient privs error when I use "update indexes":
Alter table schema_name.table_name truncate partition partition_name storage update indexes;
What priv does master need to perform statement successfully when there's data in it?
Does using 'update indexes' needs extra priveleges?
Thanks in Advance
Gagan

Hi Its Oracle 10.2.0.4 64 Bit on HP UX.
I dont have the exact error as I got this much information only from the end user....It will be couple of hours more then he will be available again
ok so for Truncate we need 'Drop any' privs but to use clause 'update indexes' alongwith do we need some extra privelege?
Thanks again
Gagan

Alter Table 's Tablespace

Dear All ,
I have 10g database on rehl5 .I move table's(T_TRANSACTION_TABLE) tablespace(USERS) to tablespace (IMAGES) .
It completed successfully
MY command is
ALTER TABLE USERS MOVE TABLESPACE IMAGES
and
ALTER INDEX USERS REBUILD TABLESPACE IMAGES
Problem is transaction_images table show using table space IMAGES but store data in USERS table space .
I check this using em->administrator->schema->Table
and i also check DBA_SEGMENT,DBA_EXTENTS both are show tablespace USERS
Note :- 1) This table contain BLOB column for save image .
2) I am also rebuild index also.
Thanks in advance
Shaikh Abdul Moyed

A LOB (CLOB or BLOB) can be stored in a different tablespace than the rest of the table. Are you certain that you're looking at the tablespace for the table segment rather than the LOB segment?
If you want to move the LOB segment to a different tablespace
ALTER TABLE <<table name>>
MOVE LOB( <<name of BLOB column>> )
STORE AS( TABLESPACE <<new tablespace>> )Additionally, I'm a bit confused by the DDL you posted
ALTER TABLE USERS MOVE TABLESPACE IMAGES
ALTER INDEX USERS REBUILD TABLESPACE IMAGESYou use USERS as a table name and as an index name in these DDL statements. But then you later talk about the USERS tablespace. I'm guessing that you really put the table name (TRANSACTION_IMAGES) in the ALTER TABLE command and that you used the correct index name in your ALTER INDEX.
Justin

Shrink,alter table move

hi
This is the scenerio
a,b,c: distinct blocks
f:free blocks
Assume the extent is like:
aaafffccccbbfb
after shrink does it become like
aaabbbccccffff
or
aaafffccccbbbf

Ricardo,
Both the things are same.They both are used to remove the fragmentation.The way they work may be different but the output of either will be the same.Free space will be on one side only ie after the hight water mark.You do it by move or by shrink,you will end up with the same thing.You put free space anywhere in the scenerio,it will come up to one end only.If it wont than I guess we are back from where we started.
That said,check back the Oracle doc for both the commands.Also search for the same topic in http://hemantoracledba.blogspot.com/2008/03/alter-table-shrink-space.html
HTH
Aman....

Alter table DDL does a FTS

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