A method includes retrieving first data from a first data store having a first database topology and second data from a second data store having a second database topology. The first data and the second data are stored in a load data set. The load data set is sorted based on a first identifier field. A first microdatabase is loaded with a first portion of the first data associated with a first value of the first identifier field and a first portion of the second data associated with the first value. A second microdatabase is loaded with a second portion of the first data associated with a second value of the first identifier field and a first portion of the second data associated with the second value. A first key map record for the first microdatabase is generated. A second key map record for the second microdatabase is generated.