Line Item Dimension

[Former Member]

Line Item Dimensions can only have one characteristic. Why would you have a Dimension as a line item and low number of repeat values? Is it simply because you only want one value for that dimension? Is this a good technique and if not what are the alternatives? Thanks

[Former Member · Accepted solution]

Hi,

For line item dimensions, there is no SID table.So Dimension Id itself used in Fat table.So that the performance will be increased in delta loading as well as in Query execution.

With rgds,

Anil Kumar Sharma .P

[Former Member]

hai harpal

waht the line item dimension mean is it has the cardinality(number of different values) is almost equal to fact table. the dimension is can have atmost 16 characterstics´then the cardinality becomes very high for that dimension and the data retrival can take time,

inorder to use the dimension to max extent, we remove the characteristic (that has the high cardinality),and kept them in the fact table. this is called line item. it is little bit expensive incase of the memory, but the data retrival is fast

i hope this will help u

[Former Member]

Thank you all very much have awarded points

[Former Member]

Hi Anil,

Its the other way round. For line item dimension there is no dimension table, only SID table is used.

Bye

Dinesh

[Former Member]

Hi Harpal,

Line Item: This means that the dimension contains just one characteristic. This indicator shows that no dimension table will be created; the SID table for the characteristic assumes the role of the dimension table. Omitting the dimension table has the following advantages:

• When loading transaction data, IDs do not have to be generated in the dimension table for the entries. If you do have a degenerate dimension, this number range operation can negatively affect performance.

• In the InfoCube star schema one table can be omitted. Potentially this table can be very large, where cardinality is high. This means that SQL-based queries become easier. In many cases, the database optimizer can select better run schedules.

However, this also has one disadvantage: You cannot include additional characteristics in a dimension that is marked as a line item at a later date. This is only possible with normal dimensions.

Bye

Dinesh