We currently only support histograms on single columns. However, it may be beneficial in some cases to collect histograms on multiple columns, especially if there is an index on multiple columns and a prefix of the columns has low cardinality (i.e., low distinct count relative to the number of rows). This issue will track the work to implement support for multi-column histograms.

Epic CRDB-16930

Jira issue: CRDB-4208

Jira issue: CRDB-13901