mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-09-08 23:39:21 +02:00
a222f7fda6
The SQL standard says that OVERLAPS should have a two-element row constructor on each side. The original coding of OVERLAPS support in our grammar attempted to extend that by allowing a single-element row constructor, which it internally duplicated ... or tried to, anyway. But that code has certainly not worked since our List infrastructure was rewritten in 2004, and I'm none too sure it worked before that. As it stands, it ends up building a List that includes itself, leading to assorted undesirable behaviors later in the parser. Even if it worked as intended, it'd be a bit evil because of the possibility of duplicate evaluation of a volatile function that the user had written only once. Given the lack of documentation, test cases, or complaints, let's just get rid of the idea and only support the standard syntax. While we're at it, improve the error cursor positioning for the wrong-number-of-arguments errors, and inline the makeOverlaps() function since it's only called in one place anyway. Per bug #9227 from Joshua Yanovski. Initial patch by Joshua Yanovski, extended a bit by me. |
||
---|---|---|
.. | ||
.gitignore | ||
analyze.c | ||
check_keywords.pl | ||
gram.y | ||
keywords.c | ||
kwlookup.c | ||
Makefile | ||
parse_agg.c | ||
parse_clause.c | ||
parse_coerce.c | ||
parse_collate.c | ||
parse_cte.c | ||
parse_expr.c | ||
parse_func.c | ||
parse_node.c | ||
parse_oper.c | ||
parse_param.c | ||
parse_relation.c | ||
parse_target.c | ||
parse_type.c | ||
parse_utilcmd.c | ||
parser.c | ||
README | ||
scan.l | ||
scansup.c |
src/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.c things start here scan.l break query into tokens scansup.c handle escapes in input strings kwlookup.c turn keywords into specific tokens keywords.c table of standard keywords (passed to kwlookup.c) gram.y parse the tokens and produce a "raw" parse tree analyze.c top level of parse analysis for optimizable queries parse_agg.c handle aggregates, like SUM(col1), AVG(col2), ... parse_clause.c handle clauses like WHERE, ORDER BY, GROUP BY, ... parse_coerce.c handle coercing expressions to different data types parse_collate.c assign collation information in completed expressions parse_cte.c handle Common Table Expressions (WITH clauses) parse_expr.c handle expressions like col, col + 3, x = 3 or x = 4 parse_func.c handle functions, table.column and column identifiers parse_node.c create nodes for various structures parse_oper.c handle operators in expressions parse_param.c handle Params (for the cases used in the core backend) parse_relation.c support routines for tables and column handling parse_target.c handle the result list of the query parse_type.c support routines for data type handling parse_utilcmd.c parse analysis for utility commands (done at execution time)