src/common/backend/parser/README Parser ====== This directory does more than tokenize and parse SQL queries. It also creates Query structures for the various complex queries that are passed to the optimizer and then executor. parser.cpp things start here scan.l break query into tokens scansup.cpp handle escapes in input strings kwlookup.cpp turn keywords into specific tokens keywords.cpp table of standard keywords (passed to kwlookup.c) gram.y parse the tokens and produce a "raw" parse tree analyze.cpp top level of parse analysis for optimizable queries parse_agg.cpp handle aggregates, like SUM(col1), AVG(col2), ... parse_clause.cpp handle clauses like WHERE, ORDER BY, GROUP BY, ... parse_compatibility.cpp Handle A db compatibal syntax and feature support parse_coerce.cpp handle coercing expressions to different data types parse_collate.cpp assign collation information in completed expressions parse_cte.cpp handle Common Table Expressions (WITH clauses) parse_expr.cpp handle expressions like col, col + 3, x = 3 or x = 4 parse_func.cpp handle functions, table.column and column identifiers parse_node.cpp create nodes for various structures parse_oper.cpp handle operators in expressions parse_param.cpp handle Params (for the cases used in the core backend) parse_relation.cpp support routines for tables and column handling parse_target.cpp handle the result list of the query parse_type.cpp support routines for data type handling parse_utilcmd.cpp parse analysis for utility commands (done at execution time)