How is sql query executed in oracle

Hi,
I want to know how is sql executed in oracle engine.
Please provide me the link or the document.
For eg: SQL>select * from emp;
how the execution happens from beginning till end.

>
I want to know how is sql executed in oracle engine.
Please provide me the link or the document.
For eg: SQL>select * from emp;
how the execution happens from beginning till end.If you are interested in databases in general (and for your
edification) you might want to look at the books below.
http://www.amazon.com/Fundamentals-Database-Systems-Ramez-Elmasri/dp/0321122267
http://infolab.stanford.edu/~ullman/dscb.html
Also, for Oracle, look at Tom Kyte (Expert Database Architecture) and to really
get down and dirty look at Jonathan Lewis's book "Cost Based Oracle". Books
on the Oracle Wait Interface (e.g. http://www.amazon.com/Oracle-Wait-Interface-Performance
-Diagnostics/dp/007222729X/ref=sr_1_1?s=books&ie=UTF8&qid=1317990537&sr=1-1 (link wraps).
It's a massive field. Good luck.
Paul...

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inner join BaseManagedEntity bme on pcv.ManagedEntityId = bme.BaseManagedEntityId
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Message was edited by:
anbarasan

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ac01e371-bc09-4b23-81d2-b251ca9edd1e wrote:
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Oracle SQL Developer Downloads</title><meta name="Title" content="Oracle SQL Developer Downloads…
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hi,
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Dear Masters,
Kindly help me to understand execution plan for an SQL statement. I have following SQL execution plan for a query in system. How should I interpret it. I thank You in advace for your guidance.
SELECT STATEMENT ( Estimated Costs = 1.372.413 , Estimated #Rows = 0 )
       5 NESTED LOOPS
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Hi Panjak,
Yeahh, there's a huge unperformatic SQL statment, what I can see from this acces plan is:
1 DBO decided to start the query on index R on MSEG, using only part of the index (only one column) with no good uniqueness, accessing disk IO-Costs for this (60mi records), and expecting many interactions (loops) in memory to filter, see CPU-Costs.
So with the parameters you gave to SQL, they start in a very bad way.
2 After that program will access the MSEG commanded by what was found on First step, also with a huge loading from DB and filtering (another where criteria on MSEG fields, not found on index R), reducing the result set to 76.717 rows.
3/4 With this, program goes direct to primary key index on MKPF with direct access (optimized access) and follow to access database table MKPF.
5 At last will "loop" the result sets from MSEG and MKPF, mixing the tuplas generating the final result set.
Do you want to share your SQL, the parameters you are sending and code which generate it with us?
Regards, Fernando Da Ró

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All,
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apps.xxoqt_item_stock_v.ORGANIZATION_NAME, apps.xxoqt_item_stock_v.ORGANIZATION_CODE,
apps.xxoqt_system_items_v1.RETAIL_PRICE, apps.xxoqt_item_stock_v.ORGANIZATION_ID,
apps.xxoqt_item_stock_v.RESERVABLE_QTY as OnHand_QTY, apps.xxoqt_item_stock_v.INVENTORY_ITEM_ID,
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apps.xxoqt_system_items_v1.pack_qty, apps.xxoqt_system_items_v1.box_qty, apps.xxoqt_system_items_v1.case_qty
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Oct 9, 2011 3:19:16 PM com.awrostamani.view.TracingViewObjectSqlQueryExecution logQueryStatementAndBindParameters
INFO: BindVars:(bAccountNumber=null)I am a bit confused here as it looks like the entire query is getting executed for sorting.
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thnks
Jdev 11.1.1.5
Edited by: in the line of fire on Oct 9, 2011 2:07 PM
Edited by: in the line of fire on Oct 9, 2011 3:19 PM

@Timo, the moment i add the line in the VO create() also tried it adding to the constructor but
I am getting this error.
java.sql.SQLSyntaxErrorException: ORA-00907: missing right parenthesis
However my issue is not with QRSLT but the issue is the query getting fired on column sorting, and in the process bind values are being set as null
my base query on which table is built is
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apps.xxoqt_item_stock_v.ORGANIZATION_NAME, apps.xxoqt_item_stock_v.ORGANIZATION_CODE,
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FROM apps.xxoqt_system_items_v1 ,apps.xxoqt_item_stock_v
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Edited by: in the line of fire on Oct 9, 2011 5:51 PM
Edited by: in the line of fire on Oct 9, 2011 6:04 PM

SQL Query executing late

Hi gurus,
I heard interview question like:
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then what you will take necessary steps. explain.
could you please full fill the answer
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A sql is a live entity, yesterday it take 10 sec today 10 minutes, it would be, if hash plan value doesn't change, a problem the I/O concurrency (more things running in the database), more data to process, older statistics because a big load of delete in any table of the query, etc. You must to examine the differences from between yesterday and today (using grid control, statspack).
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