1. A database management system comprising: a processor; a computer readable media storing: a data dictionary including rows of metadata, the metadata of each row to describe one or more of a column of a database table and a set of two or more columns forming an index stored in the database management system, wherein the metadata of at least a subset of the data dictionary rows includes: a stale flag column implemented in a database that is to be set to true by a process that executes on a machine when the metadata of a row is determined to be out of date by the process; and instructions defining database management system processes executable by the processor, the database management system processes including a stale flag process executable by the processor to set the stale flag to true when the metadata of a row of metadata is determined to be out of date; and wherein the stale flag process, when preparing data to be inserted as new rows to one or more tables: writes the data into temporary table; collects statistics on each target table column of data in the temporary table that corresponds to a table column and sets of columns forming indexes for which statistics are collected for and stored in the data dictionary; and sets the stale flag column to true for each column and index for which the temporary table statistics, when compared with statistics of the target column or index, indicate that the target column or index statistics should be updated.