Issues

• When the same SQL statement is executed concurrently 50 times, the NIC receive (RECV) bandwidth is saturated.

  databendlabs/databend#20801 · Filter by author blade83lee opened on Oct 20, 2026

• bug: REPLACE INTO … ON (key) stores several rows for one key when the duplicate source keys lie outside the table's key range, or when the table has a cluster key

  C-bug
  databendlabs/databend#20795 · Filter by author hanke580 opened on Oct 20, 2026
  

• bug: TSV/TEXT with a FIELD_DELIMITER other than tab: unload writes a delimiter inside a value as \|, load keeps the backslash (a|b is reloaded as a\|b, Smith, John as Smith\, John)

  C-bug
  databendlabs/databend#20794 · Filter by author hanke580 opened on Oct 20, 2026

• bug: CSV unload with ESCAPE = '\\' writes backslashes unescaped, so loading the file with the same format drops backslashes (C:\temp\new → C:tempnew) and merges a row ending in \ with the next row

  C-bug
  databendlabs/databend#20793 · Filter by author hanke580 opened on Oct 20, 2026

• bug: casting a DECIMAL with precision > 38 or scale > 38 to FLOAT/VECTOR returns NaN, Infinity or 0 (CAST(0.1::DECIMAL(48,45) AS FLOAT) is NaN); UPDATE, INSERT … SELECT and ALTER … MODIFY COLUMN store it

  C-bug
  databendlabs/databend#20791 · Filter by author hanke580 opened on Oct 20, 2026

• bug: REPLACE INTO on a clustered table panics with "index out of bounds: the len is 0 but the index is 0" when enable_replace_into_partitioning = 0

  C-bug
  databendlabs/databend#20790 · Filter by author hanke580 opened on Oct 20, 2026
  

• bug: REPLACE INTO that rewrites a block of a table with an inverted index never finishes (IO worker blocks in OpenDalBlockingWrite::close)

  C-bug
  databendlabs/databend#20789 · Filter by author hanke580 opened on Oct 20, 2026

• bug: INSERT … VALUES and CSV/TSV COPY INTO parse BIGINT/UINT64 text with a fraction or exponent through f64 (1760000000123456789.4 → 1760000000123456768) and clamp -9223372036854775809 to the BIGINT minimum

  C-bug
  databendlabs/databend#20786 · Filter by author hanke580 opened on Oct 20, 2026

• bug: CSV/TSV/NDJSON unload writes TIMESTAMP as session-local time without a UTC offset: the two instants of a DST fall-back hour are written identically, and the reload moves the second one an hour back

  C-bug
  databendlabs/databend#20785 · Filter by author hanke580 opened on Oct 20, 2026

• bug: integer division DIV is computed through Float64: 1760000000999999999 DIV 1000000000 is 1760000001, and x DIV 1 ≠ x above 2^53

  C-bug
  databendlabs/databend#20784 · Filter by author hanke580 opened on Oct 20, 2026

• bug: CSV/TSV COPY INTO <table> stores the NULL marker (\N, or the NULL_DISPLAY text) as a string in a STRING NOT NULL column instead of rejecting the row

  C-bug
  databendlabs/databend#20783 · Filter by author hanke580 opened on Oct 20, 2026

• bug: COPY INTO … ON_ERROR = ABORT_N skips bad rows (fewer than N) but reports ERRORS_SEEN = 0 and no FIRST_ERROR

  C-bug
  databendlabs/databend#20782 · Filter by author hanke580 opened on Oct 20, 2026

• bug: DOUBLE → DECIMAL computes value * 10^scale in f64: at scale ≥ 10 the stored decimal is off in the last digits (415210.34 becomes 415210.3400000001 after MODIFY COLUMN … DECIMAL(38,10))

  C-bug
  databendlabs/databend#20781 · Filter by author hanke580 opened on Oct 20, 2026

• bug: sum()/avg() of BIGINT/UINT64 columns overflow silently (64-bit accumulator wraps): the average of twenty epoch-nanosecond timestamps is negative

  C-bug
  databendlabs/databend#20776 · Filter by author hanke580 opened on Oct 19, 2026
  

• bug: n >= '9' AND n <= '10' on a numeric column is planned as false: the constant folder's range check compares the two string constants as strings; SELECT returns nothing, DELETE/UPDATE affect 0 rows

  C-bug
  databendlabs/databend#20775 · Filter by author hanke580 opened on Oct 19, 2026
  

• bug: the prune cache key prints DOUBLE constants with 10 fractional digits and ignores the session time zone, so WHERE f >= 0 run after WHERE f >= 0.00000000001 reuses the other query's block list and drops rows

  C-bug
  databendlabs/databend#20774 · Filter by author hanke580 opened on Oct 19, 2026
  

• bug: CSV unload writes an empty BINARY (and, with QUOTE_STYLE = 'QUOTE_MINIMAL', an empty STRING) as an empty unquoted field, which COPY INTO <table> reads back as NULL

  C-bug
  databendlabs/databend#20773 · Filter by author hanke580 opened on Oct 19, 2026
  

• bug: WHERE v:price > 100 casts the VARIANT to the literal's narrowest integer type (TRY_CAST(… AS UInt8)), so 300 and 70000 compare as NULL and rows are missed, also by DELETE/UPDATE

  C-bug
  databendlabs/databend#20772 · Filter by author hanke580 opened on Oct 19, 2026
  

• feat(storage): support cross-account RAM role / STS security token for OSS connections

  C-feature
  databendlabs/databend#20770 · Filter by author hantmac opened on Oct 19, 2026
  

• Iceberg: answer min/max from manifest column bounds

  databendlabs/databend#20769 · Filter by author djouallah opened on Oct 19, 2026
  

• Iceberg: rewrite manifests (OPTIMIZE TABLE ... COMPACT SEGMENT)

  databendlabs/databend#20768 · Filter by author djouallah opened on Oct 19, 2026
  

• Iceberg: OPTIMIZE TABLE ... COMPACT is not supported on Iceberg tables (#17566 is closed)

  databendlabs/databend#20767 · Filter by author djouallah opened on Oct 19, 2026
  

• Iceberg: branches and tags

  databendlabs/databend#20766 · Filter by author djouallah opened on Oct 19, 2026
  

• Iceberg: sort order (ALTER TABLE ... CLUSTER BY)

  databendlabs/databend#20765 · Filter by author djouallah opened on Oct 19, 2026
  

• Iceberg: set table properties with ALTER TABLE

  databendlabs/databend#20764 · Filter by author djouallah opened on Oct 19, 2026