https://community.appian.com/discussions/f/general/4571/i-have-a-generic-question-about-cdts-i-have-a-cdt-which-have-few-elementsI have a generic question about CDTs. I have a CDT which have few elements in it, some of them are multi value. Once I create a Data store containing this CDT, apian generates database tables for CDT as well as for each of the element that are multi valueen-USTelligent Community 12https://community.appian.com/thread/16513?ContentTypeID=1Fri, 27 Mar 2015 18:32:38 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:057fa6dc-c018-4381-9504-6fd40d0b83a7PhilBMy preference is to design and create a normalised database and then manually map CDTs and the data entities to the tables, nesting only lookup fields (types etc) where possible and setting the JPA annotations to write and update as appropriate.<br /><br />Nesting normalised lookups within the CDTs will mean retrieval of data for dropdowns, radio buttons etc is easily achieved using query rules, and display of the normalised data will not require any extra query rule execution. That said, there&#39;s nothing wrong with using a &quot;flat&quot; CDT and data entity layout where lookups are not nested and data is retrieved when required for display - but the data is still normalised.<br /><br />Normalised lookup data also makes adding a new option for a field as simple as inserting a row into the database lookup table, whilst non-normalised generally means you must also hold the options and/or IDs in a constant. The latter may actually be a good thing depending on the abilities of those maintaining the application.<div style="clear:both;"></div>