Module expr::explain [−][src]
Expand description
This module houses a pretty printer for MirRelationExpr
s.
Format details:
- The nodes in a
MirRelationExpr
are printed in post-order, left to right. - Nodes which only have a single input are grouped together into “chains.”
- Each chain of
MirRelationExpr
s is referred to by ID, e.g. %4. - Nodes may be followed by additional, indented annotations.
- Columns are referred to by position, e.g. #4.
- Collections of columns are written as ranges where possible, e.g. “#2..#5”.
It’s important to avoid trailing whitespace everywhere, as plans may be printed in contexts where trailing whitespace is unacceptable, like sqllogictest files.
Structs
Pretty-prints a list of indices.
An ViewExplanation
facilitates pretty-printing of a MirRelationExpr
.