PostgreSQL Query Evaluation (cont)
Each query is represented by a Query structure
- defined in
src/include/nodes/parsenodes.h
- holds all components of the SQL query, including
- required columns as list of
TargetEntrys
- referenced tables as list of
RangeTblEntrys
-
where clause as node in FromExpr struct
- sorting requirements as list of
SortGroupClauses
- queries may be nested, so forms a tree structure
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