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The fastest way of inserting and updating
The fastest way of batch inserting / updating / deleting is a buffered transaction. We recommend to call TABSDatabase.StartTransaction before bulk inserts and TABSDatabase.Commit(False) after the end of the batch operation. The use of transaction can significantly increase performance of the batch operation.
The following example illustrates the fastest way of inserting 2000 records:
| // insert data by portions of 2000 records
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| ABSDatabase1.StartTransaction;
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| FieldByName('Name').AsString := 'John';
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| ABSDatabase1.Commit(False);
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How to speed up an UPDATE query
If you are using several subqueries in an UPDATE query, you could try to transfomr your query like in the example below:
Before optimization:
| UPDATE Orders SET ShipToAddr1=(SELECT Addr1 FROM Customer WHERE CustNo=Orders.CustNo), ShipToAddr2= (SELECT Addr2 FROM Customer WHERE CustNo=Orders.CustNo) WHERE CustNo IN (1221, 2156)
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After optimization:
| UPDATE Orders SET (ShipToAddr1,ShipToAddr2) = (SELECT Addr1, Addr2 FROM Customer WHERE CustNo=Orders.CustNo) WHERE CustNo IN (1221, 2156)
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