10. A system comprising: one or more computers comprising one or more processors and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: generating, for an original attribute of a relation maintained in a database system, a respective auxiliary attribute for each interval size of a plurality of interval sizes, each interval size corresponding to a different respective power of a particular exponent base; computing, for each data entry of the relation and for each interval size of the plurality of interval sizes, a respective interval number for the interval size to which an original attribute value of the data entry belongs; storing each respective computed interval number for each data entry in the database system as an auxiliary attribute value of a corresponding auxiliary attribute for the data entry; receiving, by a query rewriter of a user device in communication with the database system, an original query having an inequality expression for the original attribute; generating a new query that replaces the inequality expression with multiple equality expressions, wherein each equality expression references a different respective auxiliary attribute, each auxiliary attribute representing a different respective interval size for values of the original attribute; providing, by the user device to the database system, the new query having the multiple equality expressions instead of the original query; and receiving, by the user device from the database system, query results that satisfy the inequality expression for the original attribute.
10. A system comprising: one or more computers comprising one or more processors and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: generating, for an original attribute of a relation maintained in a database system, a respective auxiliary attribute for each interval size of a plurality of interval sizes, each interval size corresponding to a different respective power of a particular exponent base; computing, for each data entry of the relation and for each interval size of the plurality of interval sizes, a respective interval number for the interval size to which an original attribute value of the data entry belongs; storing each respective computed interval number for each data entry in the database system as an auxiliary attribute value of a corresponding auxiliary attribute for the data entry; receiving, by a query rewriter of a user device in communication with the database system, an original query having an inequality expression for the original attribute; generating a new query that replaces the inequality expression with multiple equality expressions, wherein each equality expression references a different respective auxiliary attribute, each auxiliary attribute representing a different respective interval size for values of the original attribute; providing, by the user device to the database system, the new query having the multiple equality expressions instead of the original query; and receiving, by the user device from the database system, query results that satisfy the inequality expression for the original attribute. 11. The system of claim 10 , wherein generating the new query that replaces the inequality expression with a bounded number of equality expressions comprises: generating a disjunct of equality expressions including determining, for each interval size of a plurality of interval sizes other than a maximum interval size, whether respective equality expressions that test for an auxiliary attribute value belonging to a first interval at the interval size, a last interval at the interval size, or both, should be added to the disjunct of equality expressions.