Data Validation: Introduction

The Data Validation feature is designed to perform very basic validation of the LAS data and metadata. More sophisticated data validation routines should be implemented as database views or stored procedures that can be customised for specific requirements.

The validation routines can be executed individually or as a group.

The "Unmapped units" routine will search for curve mnemonics that have not been mapped to attribute names. This routine is now deprecated, because it is only applicable to databases based on very early versions of the standard model. In newer versions of the model, these mappings are automatically enforced by referential integrity constraints that are built into the database model.

The "Undefined Unit Conversions" routine finds missing unit conversion definitions. These definitions are required when the units of measurement as reported in the LAS file are different from the preferred units for the attribute, as specified in the metadata reference tables. For example, if the preferred units for caliper is specified as millimetres but the readings in the LAS file were reported in inches, then a conversion from inches to millimetres must be defined in the appropriate metadata reference table. See xxx for more details.

The "Duplicate best-ranked curves" routine searches for cases where a drillhole is hosting two or more instances of curves for a given attribute that have a ranking of one (1). This ambiguity could lead to duplication of rows when viewing or exporting data for the affected attributes, because data retrieval is usually based on the best-ranked curve.

The validation result in the example shown above indicates that drillhole WV024 has multiple best-ranked curves for the attributes Caliper, Gamma, LongDensity and ShortDensity. These rankings can be fixed in the LAS data browser or in the graphic preview form, as explained later.