Performance Tuning :: What Does Analyzing A Table Do For Indexes
Sep 26, 2012what analyzing a table does to existing indexes? Do I need to rebuild the indexes after dbms_stats.gather_table_stats command ?
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Performance Tuning :: Analyzing Non-sequential Snapshots In AWR
Mar 5, 2013How can check database performance in a non-sequential parts of a day using AWR tool. For example, suppose we divide a day to 2 parts: low-traffic time and high-traffic time with the following time interval:
low-traffic time : 7:00am - 10:00am and 7:00pm - 11:00pm
high-traffic time : 10:00am - 01:00pm and 4:00pm - 06:00pm
I want to examine performance using snapshots gathered by AWR. If I get 2 AWR reports for low-traffic time of day (one for 7:00am - 10:00am, another for 7:00pm - 11:00pm ) and compute average of values in 2 reports, could I called it database performance in low-traffic part of day or not?
Performance Tuning :: Required In Analyzing Network Waits From AWR
May 29, 2013We are experiencing Network waits on one of our 2-node clustered databases...In every 1 hour of clock time we are finding 700-900 seconds of Network waits
From the AWR data I find that "ARCH wait on SENDREQ" is one of the main constituent for these Network waits and as such I suspect Network between Production database and its corresponding database might be slow
Question 1) Does this understanding look correct?
Question 2) Apart from the above what could be the other causes of the Network waits. Can we point out any particular area from following AWR extract...Seeing some gc* waits initially I thought it might be due to slow interconnect between the cluster nodes but some google search denotes it is not the case...So what could be other causes? I mean which network link I would check?
Snap Id Snap Time Sessions Curs/Sess
--------- ------------------- -------- ---------
Begin Snap: 22631 22-May-13 10:00:11 976 7.9
End Snap: 22632 22-May-13 11:00:28 978 8.1
Elapsed: 60.29 (mins)
DB Time: 795.66 (mins)
[code].....
Performance Tuning :: How To Find Local And Global Indexes On Particular Table
Mar 19, 2012getting how many local and global indexes on particular oracle table
View 2 Replies View RelatedPerformance Tuning :: Practices With Indexes?
Dec 10, 2010So I was reading about indexes here:[URL]...1Is there any reason to NOT use an index? If there aren't, then should you use an index on every column on every table?
What is the general best practice with indexes? After reading the section, it seems that there are only positive impacts of using an index, so why are they not automatically created?
Performance Tuning :: Unable To Avoid Indexes
May 20, 2011Below query is getting delayed becasue of BitMap Indexes on the table. I am trying to avoid indexes by using Hints in the query but unable to do so, Details are as follows.
explain plan for
SELECT cbu_cid, cbu_cid_customer_en_nm,
COUNT (billg_acct_no) AS billg_acct_no,
SUM (subscriber_cnt) AS subscriber_cnt
FROM daily_view
WHERE (billg_system_id = 'TM' AND mktg_sub_segment_a_nm = 'TM')
AND (cbu_cid NOT IN ('0001988048', '0001379962', '0001350469'))
GROUP BY cbu_cid, cbu_cid_customer_en_nm
HAVING SUM (subscriber_cnt) > 10
ORDER BY subscriber_cnt DESC;
[code]....
I have tried with ALL_ROWS & PARALLEL.how to avoid above two indexes in a query.
Performance Tuning :: How To Partition Tables And Indexes
Jan 12, 2011So our situation is pretty simple. We have 3 tables.
A, B and C
the model is A->>B->>C
Currently A, B and C are range partitioned on a key created_date however it's typical that only C is every qualfied with created date. There is a foreign key from B -> A and C -> Bhave many queries where the data is identified by state that is indexed currently non partitioned on columns in A ... there are also indexes on the foreign keys that get from C -> B -> A. Again these are non partitioned indexes at this time.
It is typical that we qualifier A on either account or user or both. There are indexes (non partitioned on these) We have a problem with now because many of the queries use leading wildcards ie. account like '%ACCOUNT' etc. This often results in large full table scans. Our solution has been to remove the leading wildcard.
We are wondering how we can benefit from partitioning and or sub partitioning table A. since it's partitioned on created_date but rarely qualified by that. We are also wondering where and how we can benefit from either global partitioned index or local partitioned indexes on tables A. We suspect that the index on the foreign key from C to B could be a local partitioned index.
Performance Tuning :: How To Find All Indexes Scripts In Particular Schema
Aug 16, 2012getting all indexes script in particular schema.
View 4 Replies View RelatedPerformance Tuning :: Couldn't Have Indexes On Tables In Production
Sep 27, 2013I have tried a lot by alternate solutions like rearranging the order of tables in join and moving where conditions before but no success...Its a bottleneck and I could not have indexes on these tables in production...I want to change the approach in subquery
SELECT
g.COLUMN1,
g.COLUMN2,
e.COLUMN3,
g.COLUMN4,
MIN(e.dat1) KEEP ( DENSE_RANK FIRST ORDER BY date2 Desc) * -1,
min(to_char(date3,'dd-mm-yyyy'))
[code]....
Performance Tuning :: How Many Block Of Query Is Fetching With Or Without Indexes
Jun 1, 2012I don't have any dba privileges, can you share a scripts which can tell how many block my query is fetching with or without indexes. How do i also get buffer hit, how can i get i/o without sql trace as i don't have access to dump_dest
I have a below query
SELECT DISTINCT ser_id AS STA_ser_id, rct_name AS STA_name
FROM sd_servicecalls, rep_codes, rep_codes_text
WHERE ser_sta_oid = rcd_oid
AND rcd_oid = rct_rcd_oid
AND rct_name IN ('New', 'Awaiting Approval', 'Approved', 'In Progress', 'Awaiting Supplier', 'Awaiting RFC', 'Awaiting Release', 'Pending Release', 'On Hold', 'Resolved', 'Implemented', 'Closed');
Does large hash value in explain plan mean more resource needed and more time to execute the query, How can i use ADDM for the above sql.
Performance Tuning :: ORA-00439 / Feature Not Enabled / Bit-mapped Indexes
Mar 29, 2004I am having Oracle 9i relaese 2 on my db server. I am getting the following error every time I try to create a bitmap index:-
ORA-00439: feature not enabled: Bit-mapped indexes
I have queried the v$option table .Here the value of parameter Bit-mapped indexes is FALSE.
The result of v$version is :-
Oracle9i Release 9.2.0.1.0 - 64bit Production
PL/SQL Release 9.2.0.1.0 - Production
CORE 9.2.0.1.0 Production
TNS for Solaris: Version 9.2.0.1.0 - Production
NLSRTL Version 9.2.0.1.0 - Production
Actually when we created the database our installation was halted . so we manually created the database using Create database command.
How can we enable the BITMAP Index Feature now.
Performance Tuning :: Creating Normal / Composite Indexes On Fields
Feb 14, 2013I Want to tune the attached query. I have tried by creating the normal indexes and composite indexes on the fields . I feel that , Only normal index is required for this instead of composite index?
11:15:19 SQL> @slot.sql
11:16:03 SQL>
11:16:03 SQL> drop table slot purge;
Table dropped.
Elapsed: 00:00:00.05
11:16:03 SQL>
11:16:03 SQL> create table slot
11:16:03 2 (
11:16:03 3 id varchar2 (40) not null,
[code]....
- dynamic sampling used for this statement
22 rows selected.
Performance Tuning :: Only LOCAL Bitmap Indexes Are Permitted On Partitioned Tables
Feb 4, 200516:28:32 SQL> create bitmap index bp_idx_ag_id on transactions(type);
create bitmap index bp_idx_ag_id on transactions(type)
*
ERROR at line 1:ORA-25122: Only LOCAL bitmap indexes are permitted on partitioned tables
how to create bitmap index on partitiioned tables
Performance Tuning :: Create Small Functional Indexes For Special Cases In Very Large Tables
Apr 5, 2012Create small functional indexes for special cases in very large tables.
When there is a column having one values in 99% records and another values that have to be search for, it is possible to create an index using null value. Index will be small and the rebuild fast.
Example
create index vh_tst_decode_ind_if1 on vh_tst_decode_ind
(decode(S,'I','I',null),style)
It is possible to do index more selective when the key is updated and there are many records to create more levels in b-tree.
create index vh_tst_decode_ind_if3 on vh_tst_decode_ind
(decode(S,'I','I',null),
decode(S,'I',style,null)
)
To access the record can by like:
SQL> select --+ index(vh_tst_decode_ind_if3)
2 style ,count(*)
3 from vh_tst_decode_ind
4 where
5 decode(S,'I','I',null)='I'
6 group by style
7 ;
[code]....
Performance Tuning :: Merge Statement Tuning For 100M Records In Table?
Oct 31, 2011I 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].....
Analyzing Partitioned Table On Oracle
Sep 6, 2010A question regarding analyzing behavior of partition table on Oracle -
Is analyzing different sub partitions within a partition is same as analyzing that partition and what about vice-versa?
Attached File(s)
untitled.JPG ( 9.2K )
Number of downloads: 3
Performance Tuning :: Update Columns Of One Table Using Another Table
Feb 6, 2011I 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.
Performance Tuning :: Query Doing FTS On A Big Table
Jun 24, 2011Below 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.
Performance Tuning :: Partition Of Table
Jun 28, 2010What are the factors that decide on which column we should partition the table and which partition method we should chose.
View 2 Replies View RelatedPerformance Tuning :: Delete No Of Records From A Table
Aug 3, 2010I 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
Performance Tuning :: Table Partitioned With Primary Key
Aug 4, 2010I 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.
Performance Tuning :: Table Occupying Max Size
May 9, 2011Objective : 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
Performance Tuning :: Big Table Data Maintenance
Jun 17, 2011We 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.
Performance Tuning :: Remove Table Fragmentation
Dec 29, 2011I 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.
Performance Tuning :: Stale Statistics For Table?
Apr 27, 2012From 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.
Performance Tuning :: DML Slow When Table Have Many Rows
Sep 4, 2011If 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 RelatedPerformance Tuning :: Stats On A Partitioned Table?
Aug 8, 2013Is 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?
Performance Tuning :: Initial Extent For Table?
Mar 19, 20121.2 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 RelatedPerformance Tuning :: Managing Large Table?
Aug 26, 2011I 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]....
SQL & PL/SQL :: Indexes For Query Performance?
Mar 16, 2010Lot of my tables are just for join purpose , a table with just with two columns both FK , I did not add any composite PK to this table, lot my queries uses this table , because it does not have composite PK will the query be slow ? what I have to do to increase performance querying with such tables ?
View 5 Replies View Related