Improving SQL Performance
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· | RequestLive property value
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· | Available indexes for conditions from WHERE clause
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· | Rewriting a query with OR conditions as a UNION
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· | Available indexes for JOIN conditions
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· | Available indexes for ORDER BY clause
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· | Available indexes for GROUP BY clause
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· | Select from in-memory tables
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· | SELECT INTO vs INSERT SELECT
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SELECT * FROM customer WHERE City='Kapaa Kauai' AND State='HI'
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ABSTable1.AddIndex('idxCityState', 'City;State', []);
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SELECT * FROM customer WHERE Upper(City)='KAPAA KAUAI'
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ABSTable1.AddIndex('idxCity_nocase', 'City', [ixCaseInsensitive]);
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SELECT Event_Name,Venue FROM Events e JOIN Venues v ON (e.VenueNo = v.VenueNo)
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VenuesTable.AddIndex('idxVenueNo', 'VenueNo', [ixPrimary]);
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EventsTable.AddIndex('idxVenueNo', 'VenueNo', []);
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SELECT * FROM table WHERE (Field1 = 'Value1') OR (Field2 = 'Value2')
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SELECT ... WHERE Field1 = 'Value1'
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UNION
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SELECT ... WHERE Field2 = 'Value2'
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SELECT * FROM Employee ORDER BY LastName, FirstName
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ABSTable1.AddIndex('idxLastNameFirstName', 'LastName;FirstName', []);
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SELECT * FROM Employee GROUP BY FirstName
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ABSTable1.AddIndex('idxFirstName', 'FirstName', []);
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