feat(query): support SYSTEM$STREAM_HAS_DATA as scalar function#19713
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dantengsky wants to merge 2 commits intodatabendlabs:mainfrom
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feat(query): support SYSTEM$STREAM_HAS_DATA as scalar function#19713dantengsky wants to merge 2 commits intodatabendlabs:mainfrom
dantengsky wants to merge 2 commits intodatabendlabs:mainfrom
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Rewrite system$stream_has_data(name) and stream_has_data(name)
as sugar functions that expand to a scalar subquery:
(SELECT has_data FROM stream_status(name))
This provides Snowflake-compatible syntax for use in task WHEN conditions:
CREATE TASK my_task
WHEN SYSTEM$STREAM_HAS_DATA(my_stream)
AS ...
Stream name validation is delegated to the existing stream_status
table function, avoiding any duplicated logic.
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Summary
Add support for
SYSTEM$STREAM_HAS_DATA('stream_name')andstream_has_data('stream_name')as scalar functions.Previously,
stream_has_datawas registered in the sugar function list but had no rewrite implementation, causing "unknown function" errors at runtime. The only way to check stream status was via thestream_statustable function in aFROMclause, which could not be used as a scalar expression.This PR rewrites both function names as sugar functions that expand to a scalar subquery:
This allows
SYSTEM$STREAM_HAS_DATAto be used in any scalar expression context, such asSELECTstatements and boolean expressions. Supports unqualified, two-part (db.stream), and three-part (catalog.db.stream) stream name references.Tests
Type of change
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