A textual search index is used to identify data objects that have numerical properties that satisfy search queries. As described herein, a search index contains search index entries, each of which specifies a reference string and a set of data object identifiers. When an original search query is received, the search query is transformed into a transformed search query such that numerical comparison query elements in the original search query are transformed into equivalent textual comparison query elements. The search index is then used to identify ones of the data objects that satisfy the transformed search query. A list of the identified data objects may then be provided in response to the original search query.