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Message Posted: Thu, 23 Sep 2004 @ 10:24:53 GMT


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Subj:		Re: Overhead of Identity columns

From:		Dieter Noeth

Jim Downey wrote:

Has anyone had experience with the 'identity' feature? What is the overhead involved in loading a table with this feature?

You can use FastLoad/MLoad for a identity table only in V2R5.1. The overhead is probably not higher than a InMod creating the sequence...

Can you tell read the catalog (DBC) and determine which columns have this feature?

In dbc.columns there's IdColType, but the details are hidden in dbc.idcol:

     REPLACE VIEW IdCols AS
     SELECT dbase.DatabaseName,
                tvm.TVMName AS TableName,
                tvfields.FieldName AS ColumnName,
                tvfields.FieldType AS ColumnType,
                tvfields.Nullable,
                tvfields.CommentString,
                tvfields.TotalDigits(FORMAT 'Z9') AS DecimalTotalDigits,
                tvfields.ImpliedPoint(FORMAT 'Z9') AS DecimalFractionalDigits,
                tvfields.IdColType,
            idcol.AvailValue,
            idcol.StartValue,
            idcol.MinValue,
            idcol.MaxValue,
            idcol.Increment,
            idcol.Cyc
     FROM DBC.TVM
        JOIN DBC.tvfields
          ON tvm.tvmid = tvfields.tableid
        JOIN DBC.Dbase
          ON tvm.DatabaseId = dbase.DatabaseId
        JOIN dbc.idcol
          ON idcol.TableId = tvm.tvmid
          AND IdColType IS NOT NULL;

Dieter


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