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| oracle_sql_processing [2019/08/11 20:58] – [SQL Processing] andonovj | oracle_sql_processing [2020/10/19 07:29] (current) – 86.49.253.137 | ||
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| =====Overview===== | =====Overview===== | ||
| - | The SQL processing like any other processing of code. It comes from a human and needs to go back to a human :) The problem is, through how many stops it will pass. | + | The SQL processing like any other processing of code. It comes from a human and needs to go back to a human :) The problem is, through how many stops it will pass |
| Below you can see a basic representation on the possible wait times for any query: | Below you can see a basic representation on the possible wait times for any query: | ||
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| This picture, clearly displays why it isn't ALWAYS A DATABASE FAULT :) Often the database is intermediary point between the User and the data. | This picture, clearly displays why it isn't ALWAYS A DATABASE FAULT :) Often the database is intermediary point between the User and the data. | ||
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| + | =====Calls===== | ||
| + | Before we start speaking of SQL processing, we should discuss something very important and that is how ORACLE communicate and operate in general. | ||
| + | Oracle kernel is using requests called " | ||
| + | |||
| + | DB Calls: | ||
| + | * Parse | ||
| + | * Execute | ||
| + | * Fetch | ||
| + | |||
| + | Operation System (OS) Calls: | ||
| + | * WAIT | ||
| + | * STAT | ||
| + | |||
| + | These calls are accomplished using different functions: | ||
| + | |||
| + | {{ : | ||
| =====SQL Processing ===== | =====SQL Processing ===== | ||
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| * Close Cursor | * Close Cursor | ||
| - | *-Optional steps in case of hard parse | + | *- Only when hard parse is needed |