[quinnj]

Reading a dataset whose filter excludes every file, or a directory containing only schema metadata, currently throws BoundsError when accessing a column or converting through Tables.columntable or Tables.rowtable. The schema is valid, but the loader never initializes its columns.

Initialize an empty vector for each declared column when no partitions are selected, matching the single-file reader's existing behavior. Preserve the discovered schema and logical-type overrides, and document that a schema must still be available from metadata or an existing data file.

Validation: the unchanged implementation passes 21 controls and errors on 30 public empty-dataset operations on both actual Julia 1.3.1 and 1.13.1. The fix passes all 51 controls plus 420 permanent checks on both versions, covering both constructors, fallback and metadata schemas, metadata-only directories, all column names and types, row/column conversion, unused callbacks, and reading again after close. Both full suites pass with four threads and bounds checking: 4,588 checks on Julia 1.3.1 and 4,574 on Julia 1.13.1. An independent agent privately reviewed the complete diff and schema/iteration/loading/close paths and found no blocker. git diff --check passes. No package dependencies, exports, or version changes.

Hosted validation at aebbf1274af9d2f57d4274acd27ea9e01ff2fce7: all nine Julia 1.3/current/nightly jobs on Linux, macOS, and Windows and both coverage checks pass. Each uploader log confirms acceptance for this repository and commit; all nine reports are processed at 86.84%. No coverage threshold was changed.

Normally merged as c67ff831c2afc5ab412da1bd475b13fef3e0906e. The merged tree matches the fully tested PR tree. All nine exact-merge native jobs pass, and all nine correctly addressed coverage reports are accepted and processed at 86.84%.

Co-authored by Codex

AI disclosure: This work was prepared with assistance from OpenAI Codex.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.84%. Comparing base (d4f28a6) to head (aebbf12).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #204      +/-   ##
==========================================
+ Coverage   86.81%   86.84%   +0.03%     
==========================================
  Files          10       10              
  Lines        1600     1604       +4     
==========================================
+ Hits         1389     1393       +4     
  Misses        211      211              

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