Performance Tuning :: Where Filter Result Rows Save Before Join And Group By Operation
Jul 7, 2012Where filter middle_rows save before join and grop by operation?
It is save rows in PGA Private SQL Area or save blocks in SGA databuffer?
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Performance Tuning :: Why There Is No Row Resource Operation Information In Tkprof Output
May 13, 2011why there is no "Row Source Operation" information when I trace a long and complicated SQL query (It takes at least 25 minutes ro run)?
However, I can get the "Row Source Operation" information for a simple SQL Query.
Here are the tkprof output for a simple query and complicated query:
tkprof Output for a simple query
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 1 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 13 0.00 0.00 0 16 0 173
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 15 0.00 0.00 0 16 0 173
Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 3139
Rows Row Source Operation
------- ---------------------------------------------------
173 TABLE ACCESS FULL MY_TABLE (cr=16 pr=0 pw=0 time=0 us)
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 13 0.00 0.00
SQL*Net more data to client 24 0.00 0.00
SQL*Net message from client 13 5.33 5.47
Tkprof output for a complex query
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 1 0.38 0.40 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 0 0.00 0.00 0 0 0 0
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 2 0.38 0.40 0 0 0 0
Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 3139
No Row Source Operation information here 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 73062 0.25 692.23
db file scattered read 16099 0.18 76.65
latch: shared pool 4 0.02 0.03
latch: cache buffers chains 3 0.04 0.04
latch free 16 0.00 0.00
Performance Tuning :: Join With 30 Tables
Jan 16, 2012I have to do the optimization of a query that has the following characteristics:
- Takes 3 hours to process
- Performs the inner join with 30 tables
- Produces an output of 280 million records with 450 fields
First of all it is not feasible to make 30 updates (one for each table) to 280 million records.
The best solution that I had found so far was to create 3 temporary tables, where each of them to do the join with 1/3 of the 30 tables, and in the end I make the join between the main table and these three tables temporary.
I know that you will ask (or maybe not) to the query and samples, but it is impossible to create 30 examples.
how to optimize this type of querys that perform the join with multiple tables and produce a large output with (too) many columns.
Performance Tuning :: When To Use Sub-query And When To Use Join
Dec 14, 2010In SQL, almost all the thing which are possible with join is possible with sub-query also and vice-a-versa.
So when should I use sub-query and when should I go for join?
Performance Tuning :: Join Condition In Index?
Mar 14, 2012For a hash join statement, is it beneficial to have the join condition objects in the index as well as the objects in the where clause?
View 19 Replies View RelatedPerformance Tuning :: Against Count With Group By Clause
Mar 31, 2012This query is taking 7 hours to execute as I am retrieving data from history table dept_hist.
select count(distinct empid), e.group_nm, d.date,
from emp e, dept_hist d
where e.deptno = d.deptno
and e.up_ts > sysdate -30
[Code]...
Its taking 7 hours to execute.restructing this query.
Performance Tuning :: Demonstrate Working Of OCI Client Result Cache?
Jan 2, 2013I'm trying to demonstrate the working of the OCI client result cache. I've set some parameters,orcl> sho parameter result_cache
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
client_result_cache_lag big integer 3000
client_result_cache_size big integer 1000000
result_cache_max_result integer 5
result_cache_max_size big integer 1984K
result_cache_mode string FORCE
result_cache_remote_expiration integer 0
If I understand the docs correctly, that should be all that is needed.I've complied and run the cdemoqc and cdemoqc2 OCI demos, but I never get anything in the V$CLIENT_RESULT_CACHE_STATS or CLIENT_RESULT_CACHE_STATS$ views. This is probably because the sessions exit after running the queries.
So I've also tried repeating arbitrary queries through cdemo2, which gives a persistent session, but there is still nothing in those views and furthermore the v$result_cache_objects.scan_count for my queries keeps increasing. So I don't think think the client side cache is working.
Performance Tuning :: Force Optimizer To Consider All Join Permutations?
Oct 14, 2013I'm looking to see if there is a way (fully expecting it to be an underscore, or two...) to force the optimizer to keep churning until all permutations are exhausted.I'm aware that it, to paraphrase, cuts out when it's spent more time parsing than it would just running it based on it's estimates.
I've got some irritating problems with xml rewrite, xml indexes and access paths/cardinalities etc and I'm really needing the entire thing considered as a one off for debugging this. I've already cranked up the maximum permutations to the max but it's not enough, it shorts out after 5041 permutations (I'd set that to 80000 max).
I know you'd not want to do this in the real world but I cant get the damned thing to run the plan I want in a 10053 so I can see the values it has there. I know I can hint it, but I'm trying to ascertain why it's not even considering it in a "normal" parse.
Performance Tuning :: Slow Join Between Dba_tab_cols And Dba_types
Nov 14, 2012The product I work on requires a query to tell us what tables are dependent on certain types.
SELECT dba_tab_cols.owner,
dba_tab_cols.table_name,
dba_tab_cols.data_type_owner,
dba_tab_cols.data_type
FROM dba_tab_cols
JOIN dba_types
ON dba_types.owner = dba_tab_cols.data_type_owner
AND dba_types.type_name = dba_tab_cols.data_type
WHERE (dba_types.owner IN ('SCHEMA1', 'SCHEMA2'......))
I find this query to be pretty slow. I think it is because data_type_owner in dba_tab_cols is not indexed. Adding an index is not an option because users expect our product to read-only.
Performance Tuning :: Explain Plan - %CPU Seems To Be Worse For JOIN Near Top?
Oct 24, 2011however I was able to identify a poorly performing query that seemed to be maxing out our CPU. I have been trying to understand the Explain Plan. The plan below is from our test system which has considerably less information in the tables than our PROD system.
I can see there are a bunch of table scans at the end which may indicate missing indexes, but I am unclear on whether this is actually a problem as the %CPU seems to be worse for the JOIN near the top of the plan.
-------------------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes |TempSpc| Cost (%CPU)| Time | Inst |IN-OUT|
-------------------------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1870M| 3018G| | 677M (1)|999:59:59 | | |
| 1 | SORT ORDER BY | | 1870M| 3018G| 3567G| 677M (1)|999:59:59 | | |
[code]...
Performance Tuning :: Select Distinct From Cartesian Join
Sep 12, 2011Having production system: 11.2.0.1 on Windows Server x64
Test system: 9.2.0.1 on Windows XP
Problem preface: to get all unique CASEID which should be checked up by biometric system.What i should check - all CASEs for different PERSONs having same PHONEs at least among one phone type (1..4).Real table contains little bit more than 10 million records.I made test scripts.
Below the DDL for test table creation:
------------------------------------------
-- Create CASEINFO test table
------------------------------------------
DROP TABLE CASEINFO;
CREATE TABLE CASEINFO
[code]...
Below i've put SQL/DLL to make test data.number of records inserted 2 millions.
PERSON_COUNT := #/8;
------------------------------------------
-- fill CASEINFO with sample data
------------------------------------------
DECLARE
I INTEGER;
[code]...
Below SQL select to check the data in created table.
------------------------------------------
-- Check test data counters
------------------------------------------
SELECT 'TOTAL',count(*) from CASEINFO
UNION ALL
SELECT 'LEGAL',count(*) from CASEINFO where
[code]...
The PROBLEM is that i am experiencing HUGE perfomance problems on both test and production systems with that query:
select distinct b.caseid
from CASEINFO a, CASEINFO b
where (a.person<>b.person) and (a.sex=b.sex) and
(
(a.phone1=b.phone1) or
(a.phone1=b.phone2) or
(a.phone1=b.phone3) or
[code]...
This query takes almost 90 minutes to execute.And i do not know how to avoid this.Full SQL file to make test attached.
Performance Tuning :: Full Tablescan Even Though Join Is On Indexed Field
Oct 18, 2010I am posting the below query:
SELECT PEA.INCURRED_BY_PERSON_ID AS PERSON_ID,
PEA.EXPENDITURE_ENDING_DATE AS WEEK_END_DATE,
CASE
[Code].....
The explain is below:
SELECT STATEMENT ALL_ROWSCost: 48,287 Bytes: 18,428,818 Cardinality: 297,239
3 HASH JOIN Cost: 48,287 Bytes: 18,428,818 Cardinality: 297,239
1 TABLE ACCESS FULL TABLE PA.PA_EXPENDITURES_ALL Cost: 2,964 Bytes: 3,506,094 Cardinality: 194,783
2 TABLE ACCESS FULL TABLE PA.PA_EXPENDITURE_ITEMS_ALL Cost: 43,425 Bytes: 26,637,468 Cardinality: 605,397
Performance Tuning :: NESTED LOOPS JOIN And Distributed Operations?
Oct 30, 2012 I want to make sure I am describing correctly what happens in a query where there is distributed database access and it is participating in a NESTED LOOPS JOIN. Below is an example query, the query plan output, and the remote SQL information for such a case. Of particular note are line#4 (NESTED LOOPS) and line#11 (REMOTE TABLE_0002).
What I want to know is more detail on how this NESTED LOOPS JOIN handles the remote operation. For example, for each row that comes out of line#5 and is thus going into the NESTED LOOPS JOIN operation @line#4, does the database jump across the network to do the remote loopkup? Thus if there are 1 million rows, does that mean 1 million network hops? Does batchsize play a role? For example, if the database batches in groups of 100 then does that mean 10 thousand network hops?
I think each row that comes out of line#5 means a network hop to the remote database. But I do not know for a fact.I have done some abbreviating in the plan in an attempt to make it fit on the page (line#7 TA = TABLE ACCESS).
SELECT A.POLICY ,
F.MIN_MEMBER_ID,
MIN(A.EFF_DATE) EFF_DATE,
A.EXP_DATE ,
G.DESCRIPTION PROGRAM_NAME,
[code]...
Performance Tuning :: Cost Calculation For Nested Loop Join
Mar 27, 2012Following is the query on TPC-H schema.
explain plan for select
count(*)
from
orders,
lineitem
where
o_orderkey= l_orderkey.
The trace 10053 (as shown below) for this query shows nested loop join with Lineitem as outer table and Orders as inner table. It is effectively join on composite index (pk_lineitem) of Lineitem and unique index(Pk_orderkey) of Orders table. The cost calculation formula as given in the book as "outer table cost + cardinality of outer table * inner table cost " fails here. I am not able to understand this.
BASE STATISTICAL INFORMATION
***********************
Table Stats::
Table: LINEITEM Alias: LINEITEM
#Rows: 6001215 #Blks: 109048 AvgRowLen: 124.00
Column (#1): L_ORDERKEY(NUMBER)
AvgLen: 6.00 NDV: 1500000 Nulls: 0 Density: 6.6667e-07 Min: 1 Max: 6000000
[code]....
how the cost has been calculated. This does not follow the traditional nested loop cost formula as mentioned in the book.
Performance Tuning :: How Oracle Optimizer Choose Joins (hash / Merge And Nested Loop Join)
Oct 18, 2012I want to know how the Oracle optimizer choose joins and apply them while executing the query. So that I will insure about optimizer join before writing any query.
View 2 Replies View RelatedPerformance Tuning :: Returning All Rows That Equal Max (value)?
Oct 14, 2010I'm trying to write a query that counts how many sessions are active during a 1 second time interval, then returns the maximum number of sessions active during any time interval, and all the time intervals that hit that max.
Here's a sample of the inner query results:
"INTERVAL_VALUE""SESSIONS"
"13:14:47" 13
"13:14:52" 13
"13:14:54" 13
"13:19:05" 4
"13:19:28" 4
[code]....
The max(sessions) is 13, so what I want the final output to be is:
"INTERVAL_VALUE""SESSIONS"
"13:14:47" 13
"13:14:52" 13
"13:14:54" 13
Here is the create sql for the test data:
CREATE TABLE "SESSION_TABLE"
(
"SESSIONKEY" NUMBER,
"SESSION_START_TIME" TIMESTAMP,
"SESSION_END_TIME" TIMESTAMP,
CONSTRAINT "PK_SESSIONKEY" PRIMARY KEY ("SESSIONKEY")
);
[code]....
Here is my query that works:
SELECT
maxval.interval_value,
allval.sessions,
licenselimit
FROM
(SELECT
[code]....
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 :: Other Way In Oracle To Avoid Chained Rows Permanently
Jan 17, 2011There is coulmn called DATA in a table with LONG RAW datatype. we are facing more than 60% chained rows in this table because of this LONG RAW column.
It is very difficult to clean up these chained rows periodically. Since an application using this table is a business critical interms of high availability.Hence, is there any other way in oracle to avoid chained rows permanently in future?
Performance Tuning :: Importing Partitioning Rows From Many Export Files
Aug 30, 20111) I have 5 Exported Dump files.
2) All of those 5 dump files were taken in different time periods.
3) Many of those Dump files are having the same Partition records.
eg:-
Dump 1:- 01-06-2010 to 31-11-2010
Dump 2:- 01-09-2010 to 31-12-2010
4) Now i want to import all those partitioning data into a single table, without having any duplication.
Performance Tuning :: Servers Will Be Running SELECT Which Returns Zero Rows All Time
Feb 11, 2011Our application servers will be running a SELECT which returns zero rows all the time.This SELECT is put into a package and this package will be called by application servers very frequently which is causing unnecessary CPU.
Original query and plan
SQL> SELECT SEGMENT_JOB_ID, SEGMENT_SET_JOB_ID, SEGMENT_ID, TARGET_VERSION
FROM AIMUSER.SEGMENT_JOBS
WHERE SEGMENT_JOB_ID NOT IN
(SELECT SEGMENT_JOB_ID
FROM AIMUSER.SEGMENT_JOBS) 2 3 4 5 ;
[code]....
Which option will be better or do we have other options?They need to pass the column's with zero rows to a ref cursor.
Performance Tuning :: Update Million Rows In One Table With Values From Another Tables?
Feb 15, 2011I am trying to update a million rows in one table with the values from another tables.
Table being updated CI_ADJ_CHAR column CHAR_VAL_FK1
Table from which values will be used CK_ADJ columns (cx_id, ci_id)
The CI_ADJ_CHAR.CHAR_VAL_FK1 values match CK_ADJ.CX_ID and should be updated with the value CK_ADJ.CI_ID.
The CK_ADJ table has 1.3 million rows and both the columns have indexes defined. Table definitiuon mentioned below
The CI_ADJ_CHAR table has 14 million rows and will update 1 million rows and has an index on the ADJ_ID column but not on the CHAR_VAL_FK1 column.
Performance Tuning :: Get Number Of Rows Processed While Update Statement Is Still Running
Aug 25, 2010Is there any way i can Get how many rows are processing with UPDATE statement while the Update statement is still running.
View 2 Replies View RelatedForms :: Dynamic Record Group To Filter Selected Values In A Multirecord Block From A LOV
Jul 9, 2013I am working on Oracle forms 10g (Windows 7 OS).I have got one requirement to show one LOV for COLOR table. Say i have three colors BLACK, RED, BLUE in color table. Suppose in a multi record block if a user selects BLACK from a lov for one record then for the next record lov it should show only RED and BLUE. How to filter the COLOR from a LOV record group query which are already selected?
View 1 Replies View RelatedQuery To Exclude All Rows Based On Single Row Filter?
Jun 10, 2011I'm using Oracle 10g.
Question: How can I write query to return just ID only if all the codes for that ID end in 6.
If I use
SQLselect id from table_a where code like '%6'
then I also get ID=1, which I don't want.
TABLE_A
ID code
=======
1 100
1 106
2 206
3 306
3 336
4 400
Desired Result
ID
==
2
3
Server Administration :: ORA-29702 / Error Occurred In Cluster Group Service Operation
Aug 12, 2010I have deinstalled Oracle database, ASM and oracle software. I installed the oracle software, ASM and database. I have seen the error in the ASM trace called
Errors in file /opt/oracle/admin/+ASM/bdump/+asm_gmon_10518.trc:
ORA-29702: error occurred in Cluster Group Service operation
ORA-29702: error occurred in Cluster Group Service operation
SQL & PL/SQL :: Join Two Queries Together To Get Result
Dec 12, 2011How can i join two quires together to get result.
My requirement is:
First i want to select Table as we do
Select * from tab;
Then i want to describe the table as we do
Desc WO;
How can we join these two queries to have result.
SQL & PL/SQL :: How To Join 2 Tables To Get Result
Sep 7, 2010how to join 2 tables to get the result I need.I have following 2 tables (all dummy data)
Table 1
org_iddd_1dd_2dd_3
K87973789865879876432465
J87879454321981234723454
Table 2
acc_numacc_nameacc_typevol_sales
789865 Abcn185765
879876 defd494854
432465 efgg5948545
789865 hijh685765
879876 klmj794854
432465 nopl9948545
I want to join the above tables to get the following result
org_idacc_numvol_sales
K8797378986585765
K8797487987694854
K87975432465948545
J8787978986585765
J8788087987694854
J87881432465948545
I have tried writing union queries and exists clause in where and seem to get nowhere with this.
SQL & PL/SQL :: OUTER Join That Gives No Result
Aug 17, 2012i have the following problem
select dem.NUM_PCE, memo.comment
from demand dem, dem_comment memo
where CONCAT(dem.NUM_PCE,dem.NUM_DEMANDE) = memo.parentId (+)
and memo.dateCreation = (select MAX(DEM_DATE_CREATION_MEMO)
FROM dem_comment memo
WHERE memo.parentId = CONCAT(dem.NUM_PCE,dem.NUM_DEMANDE))
I should have a result with this request but there's nothing and the problem come from the fact that when the following condition is not met, there are no resulty even if there's an outer join
and memo.dateCreation = (select MAX(DEM_DATE_CREATION_MEMO)
FROM dem_comment memo
WHERE memo.parentId = CONCAT(dem.NUM_PCE,dem.NUM_DEMANDE))
This condition makes Oracle ignores the outer join..I have tried to add this:
select dem.NUM_PCE, memo.comment
from demand dem, dem_comment memo
where CONCAT(dem.NUM_PCE,dem.NUM_DEMANDE) = memo.parentId (+)
and (memo.dateCreation = (select MAX(DEM_DATE_CREATION_MEMO)
FROM dem_comment memo
WHERE memo.parentId = CONCAT(dem.NUM_PCE,dem.NUM_DEMANDE))
or memo.dateCreation is null)
but there are too much records and the result is not consistent
Tuning Searching Into Clob In Batch Operation?
Jul 3, 2012My application runs a batch procedure weekly once for searching 'A_Text' from a column in Table1 in a clob column in Table2 and inserts accordingly into another Table3.
code snippet is like this -
---
CURSOR cr_sn
IS
SELECT serial_number
[Code]....
TABLE1 will have at least 1.1 Million rows but not significantly more than this.
This procedure takes 24+ hours to complete. I tried -
1. putting parallel hint ( INSERT /*+ PARALLEL*/INTO Table3)
2. partitioning TABLE2 based on last_update_date and putting a where clause in the above query last_update_date ( last_update_date between date1 and date2)
Performance Tuning :: Tools For Database Tuning And Instance Tuning
Jul 12, 2010Looking to understand the difference between instance tuning and database tuning.
What is the difference between these two tuning exercises? I understand that an instance is memory based structures (logical) where as database consists of physical structures.
However, how does one tune a database the physical structure? Does it have to do with file placements/block sizes etc. Would you agree that a lot of that is taken care by ASM now in 11g? What tools are required/available (third party as well as oracle supplied) for these types of tuning scenarios?