Masking sensitive information in records of filtered accesses to unstructured data

A system, comprising:

• one or more computing devices;
• wherein the one or more computing devices include instructions that upon execution on or across the one or more computing devices:
• store one or more data objects in a bucket of an object storage service of a cloud computing environment, wherein an individual data object of the one or more data objects comprises a plurality of fields separated from one another using a first delimiter;
• receive, via one or more programmatic interfaces, a data access request directed to the one or more data objects, wherein the data access request indicates (a) a bucket identifier of the bucket, (b) the first delimiter, and (c) a filtering criterion expressed at least in part using Structured Query Language (SQL);
• and
• transfer a subset of contents of the one or more data objects to a destination, wherein the subset of contents is selected from the bucket using the first delimiter and the filtering criterion.

One or more non-transitory computer-accessible storage media storing program instructions that when executed on or across one or more processors:

• store one or more data objects in a bucket of an object storage service of a cloud computing environment, wherein an individual data object of the one or more data objects comprises a plurality of fields separated from one another using a first delimiter;
• receive, via one or more programmatic interfaces, a data access request directed to the one or more data objects, wherein the data access request indicates (a) a bucket identifier of the bucket, (b) the first delimiter, and (c) a filtering criterion expressed at least in part using Structured Query Language (SQL);
• and
• transfer a subset of contents of the one or more data objects to a destination, wherein the subset of contents is selected from the bucket using the first delimiter and the filtering criterion.