postgresql/src/backend/parser
Tom Lane f7f83a55bf Ensure that expandTableLikeClause() re-examines the same table.
As it stood, expandTableLikeClause() re-did the same relation_openrv
call that transformTableLikeClause() had done.  However there are
scenarios where this would not find the same table as expected.
We hold lock on the LIKE source table, so it can't be renamed or
dropped, but another table could appear before it in the search path.
This explains the odd behavior reported in bug #16758 when cloning a
table as a temp table of the same name.  This case worked as expected
before commit 502898192 introduced the need to open the source table
twice, so we should fix it.

To make really sure we get the same table, let's re-open it by OID not
name.  That requires adding an OID field to struct TableLikeClause,
which is a little nervous-making from an ABI standpoint, but as long
as it's at the end I don't think there's any serious risk.

Per bug #16758 from Marc Boeren.  Like the previous patch,
back-patch to all supported branches.

Discussion: https://postgr.es/m/16758-840e84a6cfab276d@postgresql.org
2020-12-01 14:02:27 -05:00
..
.gitignore Convert cvsignore to gitignore, and add .gitignore for build targets. 2010-09-22 12:57:04 +02:00
analyze.c Fix cases of discarding result from list API functions 2020-11-11 08:03:51 +01:00
check_keywords.pl Standardize order of use strict and use warnings in Perl code 2020-09-21 17:04:36 +02:00
gram.y Ensure that expandTableLikeClause() re-examines the same table. 2020-12-01 14:02:27 -05:00
Makefile Split all OBJS style lines in makefiles into one-line-per-entry style. 2019-11-05 14:41:07 -08:00
parse_agg.c Add for_each_from, to simplify loops starting from non-first list cells. 2020-09-28 20:33:13 -04:00
parse_clause.c Improve our ability to regurgitate SQL-syntax function calls. 2020-11-04 12:34:50 -05:00
parse_coerce.c Add select_common_typmod() 2020-10-27 18:10:42 +01:00
parse_collate.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
parse_cte.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
parse_enr.c Update copyrights for 2020 2020-01-01 12:21:45 -05:00
parse_expr.c Remove undocumented IS [NOT] OF syntax. 2020-11-19 17:39:39 -05:00
parse_func.c Move per-agg and per-trans duplicate finding to the planner. 2020-11-24 10:45:00 +02:00
parse_node.c Go back to returning int from ereport auxiliary functions. 2020-03-25 11:57:36 -04:00
parse_oper.c Remove support for postfix (right-unary) operators. 2020-09-17 19:38:05 -04:00
parse_param.c Make procedure OUT parameters work with JDBC 2020-10-27 09:01:54 +01:00
parse_relation.c Improve the error message for an inappropriate column definition list. 2020-09-22 10:49:11 -04:00
parse_target.c Correct error message 2020-10-14 07:54:14 +02:00
parse_type.c Introduce macros for typalign and typstorage constants. 2020-03-04 10:34:25 -05:00
parse_utilcmd.c Ensure that expandTableLikeClause() re-examines the same table. 2020-12-01 14:02:27 -05:00
parser.c Allow Unicode escapes in any server encoding, not only UTF-8. 2020-03-06 14:17:43 -05:00
README Move keywords.c/kwlookup.c into src/common/. 2016-03-23 20:22:08 -04:00
scan.l Allow most keywords to be used as column labels without requiring AS. 2020-09-18 16:46:36 -04:00
scansup.c Make postgres.bki use the same literal-string syntax as postgresql.conf. 2020-10-04 16:09:55 -04:00

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
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)

See also src/common/keywords.c, which contains the table of standard
keywords and the keyword lookup function.  We separated that out because
various frontend code wants to use it too.