I need move table create$java$LOB$TABLE (only has 1 row data, and 1 column is LOB column) in a user schema to new table sapce, Why can't I drop it and recreate it with the data saved from exp?
Why would you want to drop it if you only want to move it.
ALTER TABLE ... MOVE
amd
ALTER TABLE table_name MOVE LOB(lob_columnname) STORE AS (TABLESPACE new_tablespace_name);
Related
I have dropped the all the partitions in the hive table by using the alter command
alter table emp drop partition (hiredate>'0');
After droping partitions still I can see the partitions metadata.How to delete this partition metadata? Can I use the same table for new partitions?
Partitioning is defined when the table is created. By running ALTER TABLE ... DROP PARTITION ... you are only deleting the data and metadata for the matching partitions, not the partitioning of the table itself.
Your best bet at this point will be to recreate the table without the partitioning. If there is some data you are trying to save, rename the current table, create the new table (without the partitioning), then run an INSERT from the old table to the new table.
How can I change DATA TYPE of a column from number to varchar2 without deleting the table data?
You can't.
You can, however, create a new column with the new data type, migrate the data, drop the old column, and rename the new column. Something like
ALTER TABLE table_name
ADD( new_column_name varchar2(10) );
UPDATE table_name
SET new_column_name = to_char(old_column_name, <<some format>>);
ALTER TABLE table_name
DROP COLUMN old_column_name;
ALTER TABLE table_name
RENAME COLUMN new_column_name TO old_coulumn_name;
If you have code that depends on the position of the column in the table (which you really shouldn't have), you could rename the table and create a view on the table with the original name of the table that exposes the columns in the order your code expects until you can fix that buggy code.
You have to first deal with the existing rows before you modify the column DATA TYPE.
You could do the following steps:
Add the new column with a new name.
Update the new column from old column.
Drop the old column.
Rename the new column with the old column name.
For example,
alter table t add (col_new varchar2(50));
update t set col_new = to_char(col_old);
alter table t drop column col_old cascade constraints;
alter table t rename column col_new to col_old;
Make sure you re-create any required indexes which you had.
You could also try the CTAS approach, i.e. create table as select. But, the above is safe and preferrable.
The most efficient way is probably to do a CREATE TABLE ... AS SELECT
(CTAS)
alter table table_name modify (column_name VARCHAR2(255));
Since we can't change data type of a column with values, the approach that I was followed as below,
Say the column name you want to change type is 'A' and this can be achieved with SQL developer.
First sort table data by other column (ex: datetime).
Next copy the values of column 'A' and paste to excel file.
Delete values of the column 'A' an commit.
Change the data type and commit.
Again sort table data by previously used column (ex: datetime).
Then paste copied data from excel and commit.
I have a external partitioned table with almost 500 partitions. I am trying to create another external table with same properties as of the old table. Then i want to copy all the partitions from my old table to the newly created table. below is my create table query. My old table is stored as TEXTFILE and i want to save the new one as ORC file.
'add jar json_jarfile;
CREATE EXTERNAL TABLE new_table_orc (col1,col2,col3...col27)
PARTITIONED BY (year string, month string, day string)
ROW FORMAT SERDE 'org.openx.data.jsonserde.JsonSerDe'
WITH SERDEPROPERTIES (....)
STORED AS orc
LOCATION 'path';'
And after creation of this table. i am using the below query to insert the partitions from old table to new one.i only want to copy few columns from original table to new table
'set hive.exec.dynamic.partition=true;
set hive.exec.dynamic.partition.mode=nonstrict;
INSERT OVERWRITE TABLE new_table_orc PARTITION (year,month,day) SELECT col2,col3,col6,year,month,day FROM old_table;
ALTER TABLE new_table_orc RECOVER PARTITIONS;'
i am getting below error.
'FAILED: SemanticException [Error 10044]: Line 2:23 Cannot insert into target table because column number/types are different 'day': Table insclause-0 has 27 columns, but query has 6 columns.'
Any suggestions?
Your query has to match the number and type of columns in your new table. You have created your new table with 27 regular columns and 3 partition columns, but your query only select six columns.
If you really only care about those six columns, then modify the new table to have only those columns. If you do want all columns, then modify your select statement to select all of those columns.
You also will not need the "recover partitions" statement. When you insert into a table with dynamic partitions, it will create those partitions both in the filesystem and in the metastore.
I would like to know which is the command to convert a temporary table to permanent table in Oracle.
Other issue is about the index. An index used in a temporary table will be the same used in a permanent table, if I convert it?
You can't convert a table from a temporary table to a permanent table.
You can create a new permanent table that matches the structure of the temporary table
CREATE TABLE new_permanent_table
AS
SELECT *
FROM old_temporary_table
WHERE 1=0;
Or you could get the DDL for the temporary table using the DBMS_METADATA package and manually edit the DDL to create the new permanent table.
Then you can create whatever indexes you would like on the new permanent table and drop the old temporary table. Once the old temporary table is dropped, you can rename the permanent table to use the name of the old temporary table if you would like.
How can I alter a partitioned table (in Oracle 10g Database) to a new table space for not only the partitions but also the table itself? Which I mean is, I can do following without issues,
--sql
alter table abc move partition abc01 tablespace new_tablespace;
alter table abc move partition abc02 tablespace new_tablespace;
alter table abc move partition abc03 tablespace new_tablespace;
but somehow the table's definition is still associating with the old table space, and and I have moved all tables data off the old table space. If I query the dba_segment for the old table space, there is nothing there. My question is, may I drop the old table space, even no data in the data files in the old table space, but somehow those partitioned tables definitions still associating with the old table space?
Each partition must be moved, as you've discovered. If you want new partitions to be created in a different tablespace without specifying that new tablespace, you'd have to use the following:
alter table abc modify default attributes tablespace new_tablespace;