Microsoft Dynamics NAV automatically buffers inserts in order to send them to SQL Server at one time.
By using bulk inserts the number of server calls is reduced, thereby improving performance.
Bulk inserts also improve scalability by delaying the actual insert until the last possible moment in the transaction. This reduces the amount of time that tables are locked; especially tables that contain SIFT indexes.
Application developers who want to write high performance code that utilizes this feature should understand the following bulk insert constraints.
Bulk Insert Constraints
If you want to write code that uses the bulk insert functionality, you must be aware of the following constraints.
Records are sent to SQL Server when the following occurs:
COMMITto commit the transaction.
DELETEon the table.
You call any
CALCmethods on the table.
Records are not buffered if any of the following conditions are met:
The application is using the return value from an
INSERTcall; for example, "
IF (GLEntry.INSERT) THEN".
The table that you are going to insert the records into contains any of the following:
Fields with the AutoIncrement property set to Yes
The following code example cannot use buffered inserts because it contains a
FIND call on the GL/Entry table within the loop.
IF (JnlLine.FIND('-')) THEN BEGIN GLEntry.LOCKTABLE; REPEAT IF (GLEntry.FINDLAST) THEN GLEntry.NEXT := GLEntry."Entry No." + 1 ELSE GLEntry.NEXT := 1; // The FIND call will flush the buffered records. GLEntry."Entry No." := GLEntry.NEXT ; GLEntry.INSERT; UNTIL (JnlLine.FIND('>') = 0) END; COMMIT;
If you rewrite the code, as shown in the following example, you can use buffered inserts.
IF (JnlLine.FIND('-')) THEN BEGIN GLEntry.LOCKTABLE; IF (GLEntry.FINDLAST) THEN GLEntry.Next := GLEntry."Entry No." + 1 ELSE GLEntry.Next := 1; REPEAT GLEntry."Entry No.":= GLEntry.Next; GLEntry.Next := GLEntry."Entry No." + 1; GLEntry.INSERT; UNTIL (JnlLine.FIND('>') = 0) END; COMMIT; // The inserts are performed here.