Our UNDO space remains at a high level 85 to 95 percent. We keep adding database files and it doesn't seem to go down significantly. When we do a backup of the system where we shut the database down, it does go down some but then within a week or so it is back up again.
View 11 Repliesattached query giving consistent execution plan but different timings across run
SELECT /*+ INDEX (CRT CRT_CUN_FK_I)*/
DISTINCT odr.dve_id
FROM company_requirements crt, orders odr, lelo_products la_pct
WHERE crt.qtn_cun_id = 10035637--10000021--10035667
AND crt.ID = odr.crt_id_quote_implemented
AND NVL (odr.cancellation_date, '31-Dec-9999') = '31-Dec-9999'
[code]....
we have 4 databases, 2 on each servers, such that db1 and db2 on server1 and db3 and db4 on server2
refer count of the records for column of biggest table in the query, taken on all 4 databases (The column is nullable)
select count(*) from company_requirements crt WHERE crt.qtn_cun_id = 10035637
db1 = 73335
db2 = 89073
db3 = 81182
db4 = 82936
First I executed the query on db1 and db2 while there wasn't any user logged on to the system
db1
**********
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 1 0.06 0.08 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 1 17.47 473.39 85704 1508102 0 0
[code]...
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 1 0.00 0.00
db file sequential read 85704 0.31 460.55
latch free 1 0.00 0.00
SQL*Net message from client 1 14.98 14.98
[code]...
Why the elasped time changed when data and plan hasn't changed at all? Also why the plan has different stats for round 1 and 2 on db1 and db2?
I ran it 2 times each round each database so hard parsing shall not be issue.Also why the number of rows accessed are different in db1,db2 and db3,db4 especially for step1 when count of crt.qtn_cun_id is similar?
In fact when the query was taking long I was the only user on the system Also I used hard coded value (no bind variables at all)
I checked num_rows, distinct keys as well which are quite similar across all 4 databases Also no stats where gather during the query execution
What I should have checked or monitored?
DBMS_STATS.CREATE_STATS_TABLE
DBMS_STATS.EXPORT_SCHEMA_STATS
DBMS_STATS.GATHER_TABLE_STATS
I have used the above to get a copy of schema stats and gather new stats for specific tables into a STATS TABLE in my personal schema. What I want to do now is use this stats table to generate plans for queries where I believe stats are off. Is it even possible? To be clear, I do not want to import stats because this replaces the stats currently there. I just want to point the CBO to my stats table for generating plans.
there was a session parameter I could set to tell oracle to use my stats table when generating plans, or an explain plan clause I could use or a DBMS_XPLAN paramter I could provide that would tell these tools to use my stats table when generating a plan, or even some way to tell autotrace. But I have found none of this.
Is it possible for the DBMS_STATS "LIST STALE" command to show a stale partition but NOT have its table show as stale?
I had a scenario where the table itself AND 1 partition showed as stale. I ran a fnd_stats gather table stats just on that 1 partition. Once it was completed it showed the partition to no longer be stale. it also showed that the table was no longer stale. so I guess I do not need to run stats on the whole table as well?
so if this is the case, when would I need to run stats on the full partitioned table if running it on the partitions themselves removes the staleness of the table?
By default the DBMS_STATS package runs once every 24 hours to collect statistics for database objects and Oracle collects new statistics when enough of the data (about 10%) has changed.
My question here is how to check the table has changed 10% in database?
I load a table through sql loader which takes nearly 14 min for 8-9 millions records, once the records complete i run the analyze table compute statics to gather stats and it takes nearly 15 min. is there any ways so that i can reduce the stats timing. the stats collection command runs from other schema not from where the table is residing.
View 1 Replies View RelatedI have set the incremental stats for my partition table as it takes more than 20 min to gather , though the incremental is set to 'true' the table is getting analyzed completely.
View 3 Replies View RelatedOracle 10g has the feature of automatic stats gathering in this case is it necessary to run DBMS_STATS on tables manually. Does the stats gathered become stale when the auto stat runs ?
View 1 Replies View RelatedI am gathering stats by using below block i.e., for some 3 million records and there are 6 indexes on the table. What is the relevance of value 4 here (i.e., method_opt => 'FOR ALL INDEXED COLUMNS SIZE 4')? If I increase 4 to 250 will there be any speed change in gathering stats. My intention is to speed up the gathering of stats.
begin
dbms_stats.gather_table_stats(
ownname => SYS_CONTEXT('USERENV', 'CURRENT_SCHEMA'),
tabname => 'LEGAL_VIEW_TARGET',
method_opt => 'FOR ALL INDEXED COLUMNS SIZE 4',
cascade => TRUE
);
END;
I have a Datamart DB which has a continuously increasing volume. I run a daily optimize job, to have the data analysed using the below:-
EXECUTE dbms_stats.gather_schema_stats(ownname=> 'xxx' ,estimate_percent=> 25 , DEGREE => 4, cascade=> TRUE );
analyze table xxx.abc compute statistics; But this optimization itself is taking nearly 4 hrs to complete and I can't afford to have the delay.
Is there a better way of running this optimization?
I have several databases that i've recently upgraded from 9i to 11g. With all of them, the automatic stats gathering process has worked just fine every night during the maintenance window.
However, i have this other database that i created and it seems that the only stats being gathered are on the sys and system schemas and not the actual schema that holds all of our tables.
I did some searching, but i'm not sure i was using the right search terms, because i came up empty.
BANNER
-----------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
PL/SQL Release 11.2.0.1.0 - Production
CORE 11.2.0.1.0 Production
TNS for Solaris: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
Quote:Oracle collects new statistics when enough of the data (about 10%) has changed.I read the above statement in the oracle documentation that Oracle collects new statistics when enough of the data (about 10%) has changed every day during 10 pm to 6am .
But still i see some object statistics are stale and empty.Do i need to collect statistics for these objects manually ? and would like to know why these objects statistics were not collected during maintenance window ?
I have two tables with 113M records in DWH_BILL_DET & 103M in prd_rerate_chg_que and Im running following merge query, which is running for 13 hrs to update records, which is quiet longer time.
SQL> explain plan for MERGE /*+ parallel (rq, 16) */
INTO DWH_BILL_DET rq
USING (SELECT rated_que_rowid,
detail_rerate_flag_code,
rerate_sel_key,
[code].....
I am trying to update columns of Table A with the columns of Table B. Both these tables have 60,000 rows each. I tried this operation using following 2 queries:
Query 1
Update TableA A
set
(A.col1,A.col2,A.col3)=(select B.col1,B.col2,B.col3
from TableB
where A.CODE=B.CODE)
Query 2
Update TableA A
set
(A.col1,A.col2,A.col3)=(select B.col1,B.col2,B.col3
from TableB
where A.CODE=B.CODE)
where exists
A.code = (select B.code
from TableB B
where A.code=B.code)
When i execute these two above queries, it keeps executing indefinitely.
Below query is taking a long time...
select gam.SOL_ID,COUNT(gam.FORACID) from gam,smt where
gam.ACID=smt.ACID and gam.ACID NOT IN(select ACID from imt) and
gam.SCHM_TYPE in('SBA','CCA','CAA','ODA') and GAM.ACCT_CLS_FLG='N' and
gam.SOL_ID IN(select SOL_ID from IMT) group by gam.SOL_ID
/
attached is the explain plan.
in which index on IMT table is not used. And the query is doing a FTS on IMT table. What needs to be done to avoid FTS on IMT table.
What are the factors that decide on which column we should partition the table and which partition method we should chose.
View 2 Replies View RelatedI am using one script to delete the records from a table, its taking 1hr to delete.
declare
cursor c1 is select ownerid,ownertype from nightly_metric_projects
;
v1 c1%rowtype;
open c1;
loop
fetch c1 into v1;
exit when c1%notfound;
DELETE FROM DGT_ITEMEFFORTDATA WHERE OWNERTYPE = c1.OWNERTYPE
AND OWNERID = c1.OWNERID;
end loop;
close c1;
commit;
nightly_metric_projects--1200 records
DGT_ITEMEFFORTDATA--13200000
I have normal tables with hugh Data and would like to increase the performace by following means:
1) Add a new column in each table. Say this column Name is IS_LIVE. This new column have only two value 1 ( LIVE ) OR 0 ( NOT LIVE ).
2) Change the normal tables to Partitioned table. There would be only two partitioned in all the table. The partitioned key column would be IS_LIVE and both partitioend recrods would be in two different tablespace.
3) Added a POLICY function to these partitioned table to Always add a Query Predicate of '1' to all queuries.
I am interested to know that what kind of Indexes ( Global Or local ) would be suitable for these kind of Design.Is there any use of having Local index on IS_LIVE.Please note that Primary Key doesnot have this new column in it.
what analyzing a table does to existing indexes? Do I need to rebuild the indexes after dbms_stats.gather_table_stats command ?
View 4 Replies View RelatedObjective : To find solution to archieve data from 2 big tables which is occupying maximum size in the data base. With current data (From Jan 2005 to Sept 2011) it has records as mentioned below:
transaction - 41687927
trnansaction_dtl - 83945934
We need to load data and run monthly batches from October 2011 to current month which will increase this space.
1. Issue is there will not be having so much space.
2. Maintenance of such table is diffcult now.Also there is huge impact on performance. Can we think of partitioning the table base on date aswe query 1st table based on certain date range?
3. Most of reports use this table and creating performances issues
We have few tables in our production database which are havoc in size and will increase in size in future too so as part of the corrective measures , we have jotted down the below 3 methods to manage the size of those tables :-
1> Partitioning the table and take the export of identified partitions and after that, truncate those partition.
2> Creating history tables and remove not so current data from the original table to history table.
I have tried below steps for removing the table fregmentation but for some table i am not getting good result here.
1. It will collect the data which are having more than 100MB fragmentation.
select owner,table_name,blocks,num_rows,avg_row_len,round(((blocks*8/1024)),2)||'MB' "TOTAL_SIZE", round((num_rows*avg_row_len
/1024/1024),2)||'Mb' "ACTUAL_SIZE", round(((blocks*8/1024)-(num_rows*avg_row_len/1024/1024)),2) ||'MB' "FRAGMENTED_SPACE" from
dba_tables where owner in('a','b','c','d') and round(((blocks*8/1024)-(num_rows*avg_row_len/1024/1024)),2)
> 100 order by 8 desc;
2. then move the object(table) to the same tablespace.
alter table abc move;
alter table bcd move;
alter table efg move;
3. also rebuild the dependent objects.
alter index abc_PK rebuild online;
4. Then analyze the table which are having more than 100MB of fragmentation.
exec dbms_stats.gather_table_stats('a','abc');
exec dbms_stats.gather_table_stats('b','bcd');
exec dbms_stats.gather_table_stats('c','cdf');
after that when check the table fragmentation, i am getting the same result, which i have collected from the 1st query.
From the below query i found that there are some stale stats for 3 tables.
=================================
select table_name, stale_stats, last_analyzed
from dba_tab_statistics
where owner= 'SYSADM' and stale_stats='YES'
order by last_analyzed desc
I collect stats for those above 3 tables with dbms_stats.gather_table_stats().But no luck.After collection of stats immediately I ran the above query.But still it is showing there are stale stats for 3 tables.
how can I change "STALE-STATS" status, so that optimizer can use the updated stats eficiently.
If a table(have a primary key) is empty(after truncate),the sql of dml(insert,update) is very quickly,but if the table have many rows about 10,000,000 rows, the dml is very slowly,why?
View 6 Replies View Related1.2 million chained rows, 1.7 million blocks, etc. Initial extent for this table is 64k and next 1 mb. I would try to calculate this out better for efficiency and performance. This will not be efficient as it stands. calculate the size.
View 14 Replies View RelatedI am working with an online application with the database in Oracle 10G. We have a table with 10 million rows and this table is subjected to grow in future also. Moreover we cannot archive some of these rows as these records are required for referencing.
We have all necessary indexes on the table but querying this table takes a lot of time especially when it is joined with other tables. some methods with which I can manage this table in a better way so that queries joining this table would execute faster..
SELECT
TAB1.C6,
TAB1.C8,
TAB1.C10,
TAB3.C4,
[code]....
We are on Oracle 10.2.0.4 on Solaris 10. There is a table in my production db that has 872944 number of rows. Most of its data is now unnecessary, we need to retain, based on a date column in the table just last one month's data and delete rest of the data. So after that the table will have just 3000 rows.
However as the table was huge earlier(872k rows prior to delete) , does the delete of data release its oracle blocks and does the size of the table reduce? If not, will it rebuild the table online (online redefinition) so that the query that does a full scan on this table goes faster?
I checked using an example table that just delete of data does not remove the oracle blocks - they remain in the user_tables for that table and cost of full table scan remains same. We have a query that does the full table scan so I am thinking that after this delete I should do an online table re-definition , is that the right decision?
When i run a script that does a select from a single table (table has 33521868 records)the query is executed in about .094 seconds. I use the exact same query to insert into a temporary table and the query takes 10 minutes and more.
What should I be doing to speed up this process. Also tried using hints and it does not speed up the insert.
I have a table which contains 8,21,177 amount of data totally.Now I am trying to delete around 4,84,000 of data from this table by using just one filter i.e. my query is something like below
DELETE /*+ parallel(resource,4) */ FROM resource where created_by = 'MIGN'
This is going to delete 4,84,000 rows of data . But my current issue is this is taking lots of time to delete the data . To be precise , its almost taking 25 hours to delete this data..The created_by column is indexed .
Execution Plan
----------------------------------------------------------
Plan hash value: 2389236532
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time
|
--------------------------------------------------------------------------------
| 0 | DELETE STATEMENT | | 499 | 20459 | 39 (0)| 00:00:
01 |
| 1 | DELETE | RESOURCE | | | |
[code]....
I am inserting data using a procedure for 2012 and 2013 year which is using partitioned tables includes crore of data in a partition taking lot of time or taking months. Is there any other way by which I can insert data fast from our query.
View 14 Replies View Related