I have been asked at many interviews the same question again and again.The question is how would you test incremental data which gets loaded every day in their database. The main purpose of testing is to check if we have all the data from source and then to test if all the data copied from source got placed in respective tables as designed by developers.Magnetostratigraphy determines age from the pattern of magnetic polarity zones in a series of bedded sedimentary and/or volcanic rocks by comparison to the magnetic polarity timescale.The polarity timescale has been previously determined by dating of seafloor magnetic anomalies, radiometrically dating volcanic rocks within magnetostratigraphic sections, and astronomically dating magnetostratigraphic sections.Thermoluminescence and optically stimulated luminescence are used in archaeology to date 'fired' objects such as pottery or cooking stones, and can be used to observe sand migration.A sequence of paleomagnetic poles (usually called virtual geomagnetic poles), which are already well defined in age, constitutes an apparent polar wander path (APWP).These information can be retrieved whenever you need. If you want to succeed in a data warehouse interview, i would suggest the best i OS application(data-iq) created by a us based company and its for candidates like you . (Here ACTIVITY_DT is a custom metadata column, so we will look for change only in EMPID, NAME, CITY) For example - Following are the records in my target table as a part of History load - And these are the records which I am getting in my Incremental data So In above scenario, I compare the last record of History data (sorted on ACTIVITY_DT DESC) with the first record of Incremental data (sorted on ACTIVITY_DT ASC).
So now i can compare the staging table against the target database.Incremental loads are inevitable in any data warehousing environment.Following are the ways to render the incremental data and test it.Luminescence dating techniques observe 'light' emitted from materials such as quartz, diamond, feldspar, and calcite.
Many types of luminescence techniques are utilized in geology, including optically stimulated luminescence (OSL), cathodoluminescence (CL), and thermoluminescence (TL).
Both disciplines work together hand in hand however, to the point where they share the same system of naming rock layers and the time spans utilized to classify layers within a stratum.