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admin:optimization:plans:example [2012/02/03 19:47]
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admin:optimization:plans:example [2016/06/28 22:38] (current)
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 === Step 2: Process the HOUSEHOLDS table'​s criteria === === Step 2: Process the HOUSEHOLDS table'​s criteria ===
  
-Omnidex will perform index qualifications to process the criteria in the HOUSEHOLDS table, paying attention to Boolean operators and parentheses to insure the correct result. ​ Once this is done, Omnidex will have isolated the rows that meet this criteria, identified by a temporary file containing index pointers.+Omnidex will perform index qualifications to process the criteria in the HOUSEHOLDS table, paying attention to Boolean operators and parentheses to insure the correct result. ​ Once this is done, Omnidex will have isolated ​index pointers for the rows that meet this criteria.
  
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 === Step 3: Join from HOUSEHOLDS to INDIVIDUALS === === Step 3: Join from HOUSEHOLDS to INDIVIDUALS ===
  
-Omnidex will join from the HOUSEHOLDS table to the INDIVIDUALS table. ​ Omnidex has several techniques for optimizing table joins. ​ In this case, it will use the primary key values in HOUSEHOLDS as criteria against thed HOUSEHOLD index in the INDIVIDUALS table.  ​Once this is done, Omnidex will have isolated rows in the INDIVIDUALS table that meet the criteria from the HOUSEHOLDS ​table.+Omnidex will join from the HOUSEHOLDS table to the INDIVIDUALS table. ​ Omnidex has several techniques for optimizing table joins. ​ In this case, it will use the primary key values in HOUSEHOLDS as criteria against thed HOUSEHOLD index in the INDIVIDUALS table. ​ Omnidex will then have isolated ​index pointers for rows in the INDIVIDUALS table that link to the previously qualified ​HOUSEHOLDS ​rows.
  
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 === Step 4: Process the INDIVIDUALS table'​s criteria === === Step 4: Process the INDIVIDUALS table'​s criteria ===
  
-Omnidex will perform index qualifications to process the criteria in the INDIVIDUALS table. ​ This will further refine the index pointers ​already identified by processing in the HOUSEHOLDS ​table.+Omnidex will perform index qualifications to process the criteria in the INDIVIDUALS table. ​ This will further refine the index pointers ​so that they reflect criteria from both tables, as well as the table join itself.
  
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 === Step 5: Aggregate counts in the INDIVIDUALS table=== === Step 5: Aggregate counts in the INDIVIDUALS table===
  
-Omnidex will aggregate counts in the INDIVIDUALS table by scanning its indexes ​and filering ​the results using the index pointers ​set aside from the previous steps +Omnidex will aggregate counts in the INDIVIDUALS table using indexes ​on the GROUP BY columns, while also intersecting with the index pointers ​that were isolated while processing criteria and table joins.
  
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 === Step 6: Return the final result set === === Step 6: Return the final result set ===
  
-Omnidex will finally return the result set of the query. ​ When possible, Omnidex will return the first rows as soon as they are available, even if the later rows are still being processed. ​ This speeds query execution, and also helps when only the first screenfuls of data are going to be requested.+Omnidex will finally return the result set of the query. ​ When possible, Omnidex will return the first rows as soon as they are available, even if the later rows are still being processed. ​ This speeds query execution, and also helps when only the first screenfuls of data are going to be viewed.
  
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 ====== Additional Resources ====== ====== Additional Resources ======
 See also: See also:
-{{page>:​admin:​indexing:​see_also&​nofooter&​noeditbtn}}+{{page>:​admin:​optimization:​see_also&​nofooter&​noeditbtn}}
  
 {{page>:​bottom_add&​nofooter&​noeditbtn}} {{page>:​bottom_add&​nofooter&​noeditbtn}}
 
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