Server Administration :: Command To Determine Which Table Can Benefit From Shrinking
Apr 14, 2010
I use following command to determine which table can benefit from shrinking
select * from
table(dbms_space.asa_recommendations('FALSE', 'FALSE', 'FALSE'))
order by reclaimable_space desc
then i give following command to get reclaimable space
alter table t1 enable row movement ;
alter table t1 shrink space cascade;
alter table t1 disable row movement ;
in table t1 427MB was shown as reclaimable space, after executing above commands, i run dbms_space procedure again to check the out come, but result was same.I understand tablespaces are by default ASSM in 11g, none of table has LONG datatype or LOB indexes or MVIEW with ON COMMIT.
I have installed Oracle Database 11g.2 by database configuration assistant on windows XP as and adminstrator on my laptop(no connection to network),but when I want to create database I face this warning: error securing database control ,Datatbase control has been brought up in non-secure mode . to secure the database conntrol execute following command....(error is attached).
We have quarterly and yearly processes that deletes and updates data for millions of rows crossing different tables. To make room on the file system I would either like to remove empty datafiles (my preference) or coalesce TS to compact the data than remove the empty datafile.
Having said that, any query that can show me if a datafile has any data in it or a query that can show me whether a TS is a good candidate to be coalesced maybe a query with something displaying a percentage as to free and used extents and a YES/NO column whether to be coalesced or not.
1) We have a 4TB database and using BIG FILE datafiles for all the datafiles(DATA,INDEX,UNDO and TEMP).
Few tables have grown extremely to consumed entries ASM disks. we have purged its data. so the the data file have the free space. However the data have another tables' LOB segment at the end of the datafile. so we could not shrik the data file.
we could do data pump export/import or moving the different tablespace. But we do not have ASM space. 11g Tablespace re-organization also require additional space(beleive equal amount of tablespace)
Is there any way to shink the data file?
2) let us assume my datafile is 190G and it has 80 free space with in the datafile and my ASM diskgroup size is 200G(4x50GB).
If I drop 1 ASM disk from my diskgroup, will it shrink the datafile becuase it has only free space ?
3) we are having TDE license...But not advanced compression...can we do segment movement with table compression?
I was about to move some tables from one table space to another but it seems it is not possible to move partitioned tables between table spaces of different block sizes.
So far the only option I have is to export and then import back the data.
know if there is any way to move a partitioned table between table spaces of different block size?
1.Is it necessary to reorganize a table and index after the deletion of records from table ? Because i see some change in table size after table and index reorganization.
2.Will re org table and index improve the database performance ?
SQL> Alter Table tb_hxl_user Shrink Space Cascade; Alter Table tb_hxl_user Shrink Space Cascade * ERROR at line 1: ORA-10635: Invalid segment or tablespace type
SQL> desc tb_hxl_user; Name Null? Type ----------------------------------------- -------- ---------------------------- STATEDATE NOT NULL DATE USERNUMBER NOT NULL VARCHAR2(13) PROVCODE NOT NULL NUMBER
We are running 11g (11.2.0.3)We have a "working table" that is empty at the beginning of the day.Then we start adding rows (insert) with a key column called STATE with a value of 100.At the same time, there are other apps that pickup data in state 100 , process that data and change that state to 200 or 300.There is also another app that pickup data in state 200 , process that data and change that state to 300 or 400.
So in summary, the data on that table is at the beginning empty, then all the rows are in state 100, they slowly move to different states (200, 300, etc) and by the end of the day, they are all in 400.
My question is what would be the best way to collect stats on this table?
I was thinking to create an hourly job to collect stats on that table: exec dbms_stats.gather_table_stats ( ownname => 'SCOTT', tabname => 'WORK_T
Name Null Type ------------------------------ -------- ------------------------ ENTITY_ID NOT NULL VARCHAR2(100 CHAR) ENTITY_TYPE_ID NOT NULL NUMBER SOURCE_ID NOT NULL VARCHAR2(512 CHAR) XML_SCHEMA_ID NOT NULL NUMBER JOB_ID NOT NULL NUMBER FINGERPRINT NOT NULL VARCHAR2(100 CHAR) ENTITY_XML_DATA CLOB() ARCHIVED NUMBER(1) CREATION_DATE TIMESTAMP(6) MODIFICATION_DATE TIMESTAMP(6) ARCHIVING_DATE TIMESTAMP(6) CREATED_BY VARCHAR2(50 CHAR) MODIFIED_BY VARCHAR2(50 CHAR)
The problem is that the data of the table are 40GB while on the DB the table holds 400GB! How can I shrink and reuse that space except from drop/recreate and drop/import?
The table has no initial data, so that I can play with the INITIAL parameter. Data are inserted, updated and deleted all the time. I have run DBMS_ADVISOR which recommended to SHRINK table. I have performed the shrink :
I want to get the stale stats for Table resides at APPS schema. Is there is any table or view exists to get the details like DBA_STALE_STATS or anything? Currently I am checking LAST_ANALYZED column from DBA_TABLES?
Why do we gather table statistics manually ?Is it because of database performance.
I know In Oracle Database 10g, Automatic Optimizer Statistics Collection reduces the likelihood of poorly performing SQL statements due to stale or invalid statistics and enhances SQL execution performance by providing optimal input to the query optimizer.
Optimizer gathers statistics when 10% table rows have been changed.
3) as a workaround, i compressed these 2 SWP tables with OLTP option, and then i was able to drop the column from these 2 SWP tables.
4) Below statement is correct or not ? IF A TABLE USING BLOCK LEVEL COMPRESSION, THEN this error will come - ORA-39726: unsupported add/drop column operation on compressed tables.
if above statement is correct, then how to find out whether table data is using block level compression ?
5) we have DBMS_COMPRESSION.GET_COMPRESSION_TYPE. using this i just tried to find out, but i am getting "1" as output. I am not getting the exact meaning of it.
confirm what is the conclusion on this ?
SQL> declare rid rowid; n number; begin select max(rowid) into rid from NOVAR.PAYMENT_SWP; n := dbms_compression.get_compression_type('NOVAR','PAYMENT_SWP',rid); dbms_output.put_line(n); end; / 2 3 4 5 6 7 8 9 1
PL/SQL procedure successfully completed.
SQL> SQL> SET SERVEROUTPUT ON SQL> / 1
PL/SQL procedure successfully completed.
SQL> SELECT max(rowid) from NOVAR.PAYMENT_SWP;
MAX(ROWID) ------------------ AAsz4fAHSAAAD3IABs
(ii) 2nd table
SQL> set serveroutput on SQL> declare rid rowid; n number; begin select max(rowid) into rid from NOVAR.PREPAYMENT_SWP; n := dbms_compression.get_compression_type('NOVAR','PREPAYMENT_SWP',rid); dbms_output.put_line(n); end; 2 3 4 5 6 7 8 9 10 / 1
PL/SQL procedure successfully completed.
SQL> SELECT max(rowid) from NOVAR.INVOICELINE_SWP;
- we have 55 blocks allocated to the table (still) - 35 blocks are totally empty (above the HWM) - 19 blocks contains data (the other block is used by the system) - we have an average of about 2.8k free on each block used.
Therefore, our table
- consumes 19 blocks of storage in total. - of which 19 blocks * 8k blocksize - 19 block * 2.8k free = 98k is used for our data.
not too sure this calculation is accurate for getting the size (data)of the table.
I have a partioned table that has close to 2 billion rows and a PK of all columns. Becuase of time constrains my APP team wants the PK disabled while they pump into hundreds of thousands of rows with a batch process.
Now I am finding when I enable the PK its eating up close to close to 200GB of temp space.
Is there something I can do to reduce the amount of temp space being used?
