| How does a SQL Statement work? [message #319195] |
Fri, 09 May 2008 05:29  |
kiran.satyan Messages: 12 Registered: March 2008 Location: Bangalore |
Junior Member |
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Hi All,
SQL* Plus places each command into a buffer,when it finds a semi colon Sql* Plus executes that query.
In this explanation the "Buffer",specified is in client's Memory
or in SGA of Server(Assume we have a client connected to a Server)?
When we press enter after typing semicolon exactly what is happening?
If the execution plan is created in SGA,then what is transmitted from the client to the server.
Thanks & Regards
Kiran Sathyan
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| Re: How does a SQL Statement work? [message #319218 is a reply to message #319195 ] |
Fri, 09 May 2008 06:24   |
JRowbottom Messages: 2663 Registered: June 2006 Location: Sunny North Yorkshire, ho... |
Senior Member |
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SQL*Plus keeps a copy of the last query run internally - that's why you can re-run the query with a single key stroke.
The query is sent to the server, where it is parsed, an executpion plan is generated for it, the data is fetched, andthen the data is packed up into sets of rows based on the SQL*Plus ARRAYSIZE, and sent interactively to the client.
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| Re: How does a SQL Statement work? [message #319219 is a reply to message #319195 ] |
Fri, 09 May 2008 06:25   |
Michel Cadot Messages: 15242 Registered: March 2007 Location: Nanterre, France, http://... |
Senior Member |
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| Quote: | the "Buffer",specified is in client's Memory
or in SGA of Server(Assume we have a client connected to a Server)?
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In SQL*Plus
| Quote: | When we press enter after typing semicolon exactly what is happening?
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SQL*Plus analyzes the command to know if it is a SQL*Plus or a SQL/PLSQL command. If it is a SQL*Plus command, it executes it. If it is a SQL/PLSQL it sends it to the server.
| Quote: | If the execution plan is created in SGA,then what is transmitted from the client to the server.
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The SQL/PLSQL text.
Regards
Michel
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| Re: How does a SQL Statement work? [message #319236 is a reply to message #319195 ] |
Fri, 09 May 2008 07:50   |
kiran.satyan Messages: 12 Registered: March 2008 Location: Bangalore |
Junior Member |
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Hi Michel,
In which format SQL*PLUS transmits the SQL/PLSQL command?
All the SQL/PLSQL commands are parsed in SGA only ,then in which format it is transmitted from client to server?
So this English sentences are converted to which format?
Its pretty low level,I'm bit curious to get it displayed!
Thanks & Regards
Kiran Sathyan
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| Re: How does a SQL Statement work? [message #319238 is a reply to message #319236 ] |
Fri, 09 May 2008 08:03   |
Michel Cadot Messages: 15242 Registered: March 2007 Location: Nanterre, France, http://... |
Senior Member |
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| Quote: | In which format SQL*PLUS transmits the SQL/PLSQL command?
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Text.
| Quote: | All the SQL/PLSQL commands are parsed in SGA only ,then in which format it is transmitted from client to server?
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They are parsed in the server, so question is irrelevant.
| Quote: | So this English sentences are converted to which format?
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No conversion. This is text.
| Quote: | Its pretty low level,I'm bit curious to get it displayed!
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Add to your client sqlnet.ora:
TRACE_LEVEL_CLIENT=support
TRACE_DIRECTORY_CLIENT=<your trace directory>
TRACE_FILE_CLIENT=<your trace file>
Then all what comes in and goes out of your client is traced in the file.
Take care, it will be big soon.
Regards
Michel
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| Re: How does a SQL Statement work? [message #319245 is a reply to message #319218 ] |
Fri, 09 May 2008 08:24   |
kiran.satyan Messages: 12 Registered: March 2008 Location: Bangalore |
Junior Member |
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Hi JRowbottom ,
Thanks alot for this wonderful information.
Kiran Sathyan
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| Re: How does a SQL Statement work? [message #319247 is a reply to message #319238 ] |
Fri, 09 May 2008 08:27  |
kiran.satyan Messages: 12 Registered: March 2008 Location: Bangalore |
Junior Member |
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Hi Michel
Thank you very much for making me understand it.
I hope I'm trying to keep a good standard for my doubts.
Regards
Kiran Sathyan
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