postgresql/src/backend/parser
Tom Lane 0795da8695 Avoid invalid array reference in transformAlterTableStmt().
Don't try to look at the attidentity field of system attributes,
because they're not there in the TupleDescAttr array.  Sometimes
this is harmless because we accidentally pick up a zero, but
otherwise we'll report "no owned sequence found" from an attempt
to alter a system attribute.  (It seems possible that a SIGSEGV
could occur, too, though I've not seen it in testing.)

It's not in this function's charter to complain that you can't
alter a system column, so instead just hard-wire an assumption
that system attributes aren't identities.  I didn't bother with
a regression test because the appearance of the bug is very
erratic.

Per bug #17465 from Roman Zharkov.  Back-patch to all supported
branches.  (There's not actually a live bug before v12, because
before that get_attidentity() did the right thing anyway.
But for consistency I changed the test in the older branches too.)

Discussion: https://postgr.es/m/17465-f2a554a6cb5740d3@postgresql.org
2022-04-18 12:16:45 -04:00
..
.gitignore Convert cvsignore to gitignore, and add .gitignore for build targets. 2010-09-22 12:57:04 +02:00
analyze.c Avoid trying to lock OLD/NEW in a rule with FOR UPDATE. 2021-08-19 12:12:35 -04:00
check_keywords.pl Update copyright for 2019 2019-01-02 12:44:25 -05:00
gram.y Ensure that expandTableLikeClause() re-examines the same table. 2020-12-01 14:02:28 -05:00
Makefile Revert MERGE patch 2018-04-12 11:22:56 +01:00
parse_agg.c Fix check_agg_arguments' examination of aggregate FILTER clauses. 2021-08-18 18:12:51 -04:00
parse_clause.c Phase 2 pgindent run for v12. 2019-05-22 13:04:48 -04:00
parse_coerce.c Ensure casting to typmod -1 generates a RelabelType. 2021-12-16 15:36:02 -05:00
parse_collate.c Phase 2 pgindent run for v12. 2019-05-22 13:04:48 -04:00
parse_cte.c Update copyright for 2019 2019-01-02 12:44:25 -05:00
parse_enr.c Update copyright for 2019 2019-01-02 12:44:25 -05:00
parse_expr.c Phase 2 pgindent run for v12. 2019-05-22 13:04:48 -04:00
parse_func.c Require the schema qualification in pg_temp.type_name(arg). 2019-08-05 07:48:45 -07:00
parse_node.c Reconcile nodes/*funcs.c with PostgreSQL 12 work. 2019-06-09 14:00:36 -07:00
parse_oper.c Phase 2 pgindent run for v12. 2019-05-22 13:04:48 -04:00
parse_param.c Phase 2 pgindent run for v12. 2019-05-22 13:04:48 -04:00
parse_relation.c Phase 2 pgindent run for v12. 2019-05-22 13:04:48 -04:00
parse_target.c Remove bogus assertion in transformExpressionList(). 2021-10-19 11:35:15 -04:00
parse_type.c Require the schema qualification in pg_temp.type_name(arg). 2019-08-05 07:48:45 -07:00
parse_utilcmd.c Avoid invalid array reference in transformAlterTableStmt(). 2022-04-18 12:16:45 -04:00
parser.c Replace the data structure used for keyword lookup. 2019-01-06 17:02:57 -05:00
README Move keywords.c/kwlookup.c into src/common/. 2016-03-23 20:22:08 -04:00
scan.l Replace the data structure used for keyword lookup. 2019-01-06 17:02:57 -05:00
scansup.c Update copyright for 2019 2019-01-02 12:44:25 -05:00

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.