Abstract: A database operation is performed in a file system residing on a plurality of processing modules. The file system includes a first relation having a plurality of first-relation entries. Each of the plurality of first-relation entries has a first-relation attribute that is of interest in the database operation. A value of a distribution attribute in each of the first-relation entries is set to a unique value selected from among a domain of unique values. The first-relation entries of the first relation are redistributed among the plurality of processing modules based on the first-relation attribute and the distribution attribute. The computational operation is performed to produce a result.

Abstract: A method for preparing a transmission electron microscopy (TEM) sample for electron holography includes forming a sacrificial material over an area of interest on the sample, and polishing the sample to a desired thickness, wherein the area of interest is protected from rounding during the polishing. The sacrificial material is removed from the sample following the polishing.