User-Defined Attributes (UDAs) in Oracle Essbase are freeform text labels that can be assigned to any member of any dimension in an Essbase outline — providing a mechanism for tagging members with descriptive properties that Calc Script business rules can then use as FIX conditions. Unlike attribute dimensions (which create queryable analytical axes), UDAs are metadata tags that are visible only in the Essbase outline and in Calc Script — they cannot be used as report axes in Financial Reporting Studio or Smart View, and they do not affect how data is stored or aggregated. Their purpose is calculation parameterisation: a business rule that needs to operate on “all expense accounts” can FIX on the UDA value “Expense” rather than hardcoding a list of individual expense account names, making the rule maintainable as the account dimension grows.
UDA Implementation
| UDA Aspect | Detail |
|---|---|
| Assignment | Assigned in Essbase outline editor or through metadata import (OLU, DI dimension import) — each member can have multiple UDAs |
| Syntax in Calc Script | @ISUDA(“UDAValue”) function in FIX statement — e.g., FIX(@ISUDA(“Expense”)) operates on all members with “Expense” UDA |
| Scope | UDA applies to the specific member it is tagged to — not inherited by children; each child must be individually tagged or the @ISUDA must include descendants |
| Visibility | Visible in Essbase outline; not visible as a report axis in Smart View or FR Studio |
| Maintenance | Adding a new member to a UDA category requires adding the UDA tag to the new member — not automatic |
Common Finance UDA Patterns
Several UDA patterns recur in financial planning and consolidation EPM applications. Account type tags: UDAs like “Revenue”, “Expense”, “Balance Sheet”, “Statistical” tag account members by type, allowing allocation rules to FIX on expense accounts only rather than hardcoding account ranges. Calculation sequence flags: UDAs like “Stage1”, “Stage2” tag members that should be calculated in a specific sequence — a business rule processes Stage1 members first, then Stage2, enforcing calculation order without restructuring the dimension hierarchy. Currency conversion flags: UDAs like “TranslateAtClosing”, “TranslateAtAverage” tag account members with the appropriate currency translation rate, allowing the currency translation rule to FIX on each rate type and apply the corresponding exchange rate without an IF statement per account. These patterns make Calc Scripts more maintainable by separating the calculation logic (the script) from the data classification (the UDA assignment in the outline).
UDA Maintenance Discipline
UDA usefulness degrades over time when new dimension members are not tagged with the appropriate UDAs when they are added. A new expense account added to the Account dimension without the “Expense” UDA will not be included in the expense account calculation rule — it will silently be excluded from the FIX block, producing an incomplete calculation result. UDA maintenance must be a formal step in the dimension change management process: whenever a new member is added to a dimension, the set of UDAs that should be assigned to the new member must be explicitly evaluated and configured. Dimensions with many UDA-dependent calculation rules that are not maintained become progressively less reliable as dimension members are added without UDA tagging.
UDAs vs Member Properties vs Attribute Dimensions
UDAs, member properties (aliases, data type), and attribute dimensions all serve different purposes in characterising dimension members. UDAs are calculation tags — visible to Calc Script, not to reports. Member properties (data type, storage type, consolidation operator) control how Essbase handles the member’s data — stored vs dynamic, + vs – consolidation. Attribute dimensions provide reportable analytical axes — visible to MDX queries, Financial Reporting Studio, and Smart View. A common design error is using UDAs when an attribute dimension is needed (because the classification must be a report axis) or using attribute dimensions when a UDA would suffice (because the classification is only needed in calculation logic). Matching the tool to the purpose prevents unnecessary complexity in the dimension design.
What Goes Wrong in Practice
The specific UDA failure that most frequently produces incorrect calculation results is a UDA that is assigned only at the parent level of a hierarchy, with the assumption that child members inherit it — which they do not. Essbase UDAs are not inherited; a parent member tagged with “Expense” does not cause its children to be recognised as “Expense” in an @ISUDA FIX statement. All leaf-level members that should be included in the FIX must be individually tagged. This misunderstanding is most common among EPM developers with a background in relational databases, where category tags at the parent record are inherited by child records through the data model. Essbase’s UDA model does not work this way, and the resulting calculation errors are not immediately obvious because the FIX statement executes successfully — it simply processes fewer members than intended.
How Loop Wise Solutions Documents UDAs
We include a UDA register in every EPM dimension design document — listing every UDA value defined in the application, the dimension it applies to, which members are tagged with each UDA, and which business rules depend on each UDA FIX condition. This register serves as both a design document and an ongoing maintenance reference — ensuring that new dimension members are evaluated against every UDA category at the point of addition.
