Analyzes join cardinality without performing the full join.
Useful for detecting many-to-many joins that would explode row count.
Usage
diagnose_join(x, y, by = NULL, use_joinspy = TRUE)
Value
A list with cardinality information, or a JoinReport object if
joinspy is used.
Arguments
x
Left data frame.
y
Right data frame.
by
Join specification.
use_joinspy
If TRUE (default), use joinspy for enhanced diagnostics
when available. Set to FALSE to use built-in diagnostics only.
Details
If the joinspy package is installed, this function delegates to
joinspy::join_spy() for enhanced diagnostics including whitespace
detection, encoding issues, and detailed match analysis.
See Also
joinspy::join_spy() for enhanced diagnostics (if installed)