A system comprising: a first database; and an extract transform load process, hereinafter referred as ETL process, of a manufacturing execution system, hereinafter referred as MES, to extract data from the first database 105, perform a transformation of the extracted data, and load the transformed data into the second database, wherein the ETL process operates to: preload a cache of the MES with a subset of a set of key-value pairs stored in source data of the first database, with a goal of achieving at least a predetermined cache hit ratio for any request of a particular key-value pair among the set stored in the source data; receive a request of a key-value pair; determine whether the requested key-value pair is in the preloaded cache; retrieve the requested key-value from the preloaded cache if the requested key-value pair is in the preloaded cache; the system being characterized in that it further comprises: queue the requested key-value pair in an internal data structure of the MES, if the requested key-value pair is not in the preloaded cache, until a threshold number of accumulated requested key-value pairs are queued in the internal data structure; and execute. In response to the internal data structure queue meeting the threshold number of accumulated requested key-value pairs, a query of the source data of the first database for all of the accumulated requested key-value pairs, and a command to retrieve all of the accumulated requested key-value pairs from the source data. a first database; and an extract transform load process, hereinafter referred as ETL process, of a manufacturing execution system, hereinafter referred as MES, to extract data from the first database 105, perform a transformation of the extracted data, and load the transformed data into the second database, wherein the ETL process operates to: preload a cache of the MES with a subset of a set of key-value pairs stored in source data of the first database, with a goal of achieving at least a predetermined cache hit ratio for any request of a particular key-value pair among the set stored in the source data; receive a request of a key-value pair; determine whether the requested key-value pair is in the preloaded cache; retrieve the requested key-value from the preloaded cache if the requested key-value pair is in the preloaded cache; the system being characterized in that it further comprises: queue the requested key-value pair in an internal data structure of the MES, if the requested key-value pair is not in the preloaded cache, until a threshold number of accumulated requested key-value pairs are queued in the internal data structure; and execute. In response to the internal data structure queue meeting the threshold number of accumulated requested key-value pairs, a query of the source data of the first database for all of the accumulated requested key-value pairs, and a command to retrieve all of the accumulated requested key-value pairs from the source data. preload a cache of the MES with a subset of a set of key-value pairs stored in source data of the first database, with a goal of achieving at least a predetermined cache hit ratio for any request of a particular key-value pair among the set stored in the source data; receive a request of a key-value pair; determine whether the requested key-value pair is in the preloaded cache; retrieve the requested key-value from the preloaded cache if the requested key-value pair is in the preloaded cache; the system being characterized in that it further comprises: queue the requested key-value pair in an internal data structure of the MES, if the requested key-value pair is not in the preloaded cache, until a threshold number of accumulated requested key-value pairs are queued in the internal data structure; and execute. In response to the internal data structure queue meeting the threshold number of accumulated requested key-value pairs, a query of the source data of the first database for all of the accumulated requested key-value pairs, and a command to retrieve all of the accumulated requested key-value pairs from the source data. queue the requested key-value pair in an internal data structure of the MES, if the requested key-value pair is not in the preloaded cache, until a threshold number of accumulated requested key-value pairs are queued in the internal data structure; and execute. In response to the internal data structure queue meeting the threshold number of accumulated requested key-value pairs, a query of the source data of the first database for all of the accumulated requested key-value pairs, and a command to retrieve all of the accumulated requested key-value pairs from the source data.