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Diffstat (limited to 'src/mongo/db/query/optimizer/syntax/syntax.h')
| -rw-r--r-- | src/mongo/db/query/optimizer/syntax/syntax.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/mongo/db/query/optimizer/syntax/syntax.h b/src/mongo/db/query/optimizer/syntax/syntax.h index d44d32fbc00..03f35718871 100644 --- a/src/mongo/db/query/optimizer/syntax/syntax.h +++ b/src/mongo/db/query/optimizer/syntax/syntax.h @@ -39,6 +39,14 @@ namespace mongo::optimizer { +/** + * This is the core typedef that represents an abstract binding tree (ABT). The templated types + * represent all possible instances for a given ABT operator, each deriving from an Operator class + * that indicates the number of children nodes. + * + * NOTE: If the set of possible types in an ABT changes, please update the corresponding gdb + * pretty printer. + */ using ABT = algebra::PolyValue<Blackhole, Constant, // expressions Variable, |