Ledger Data Requirements for Data Mart
Most reporting of general ledger data shows balances and activity between two periods for one or more levels of groupings of the Chart of Accounts (COA) subaccounts. Ledger data rolled up to the fund level is often not meaningful. Therefore, it is likely that you will maintain only group models for ledger data, one model per distinct grouping hierarchy that you use in reporting.
If this is true in your case, you do not need the GL Detail Posting table to include Security granularity. You normally base grouping on a selection of general ledger Chart of Accounts account numbers.
The Data Mart uses the instance field of the GL Detail Posting table in the Data Mart Ledger Details table. Security and Currency are non-nullable fields, so if you have to build Ledger Details in the Mart, these two fields should be present in the GL Detail Posting table even if the data does not come from Eagle Accounting. Long/Short indicator is an optional informational field.