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fix(teradata): transpile SAMPLE row counts and fractions [CLAUDE] - #8670
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Teradata's SAMPLE clause was always stored as a list of expressions, which other dialects can't generate, so it became an empty `TABLESAMPLE ()`. A single integer sample is now parsed as a row count (size) and a single fraction as a percentage, e.g. SAMPLE 0.25 -> Snowflake TABLESAMPLE (25). Multiple sample sets have no equivalent, so they're dropped with an unsupported warning. Closes tobymao#8669 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
georgesittas
approved these changes
Oct 19, 2026
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Closes #8669
The Teradata parser kept the SAMPLE value in
TableSample.expressions, which only the Teradata generator reads, so other dialects produced an emptyTABLESAMPLE ().TeradataParser._parse_table_samplenow maps a single integer tosize(row count) and a single fraction topercent. For example,SAMPLE 0.25becomes SnowflakeTABLESAMPLE (25)and DuckDBTABLESAMPLE (25 PERCENT). The Teradata generator convertspercentback to a fraction, so round trips stay the same.SAMPLE 1.00keeps its decimal point so it isn't read back as a row count.Multiple sample sets (
SAMPLE 0.6, 0.25) return disjoint samples in Teradata and have no equivalent elsewhere. The base generator now drops them with an unsupported warning instead of emittingTABLESAMPLE ().Tests: added cases to
TestTeradata.test_teradata. I also ran the DuckDB output against DuckDB. The full unit suite (SKIP_INTEGRATION=1 python -m unittest) passes.I used Claude Code to write this change and reviewed it myself.
🤖 Generated with Claude Code