postgresql/src/backend/parser
Tom Lane 1015162c35 Fix handling of extended expression statistics in CREATE TABLE LIKE.
transformTableLikeClause believed that it could process extended
statistics immediately because "the representation of CreateStatsStmt
doesn't depend on column numbers".  That was true when extended stats
were first introduced, but it was falsified by the addition of
extended stats on expressions: the parsed expression tree is fed
forward by the LIKE option, and that will contain Vars.  So if the
new table doesn't have attnums identical to the old one's (typically
because there are some dropped columns in the old one), that doesn't
work.  The CREATE goes through, but it emits invalid statistics
objects that will cause problems later.

Fortunately, we already have logic that can adapt expression trees
to the possibly-new column numbering.  To use it, we have to delay
processing of CREATE_TABLE_LIKE_STATISTICS into expandTableLikeClause,
just as for other LIKE options that involve expressions.

Per bug #18468 from Alexander Lakhin.  Back-patch to v14 where
extended statistics on expressions were added.

Discussion: https://postgr.es/m/18468-f5add190e3fa5902@postgresql.org
2024-05-22 17:54:17 -04:00
..
.gitignore Convert cvsignore to gitignore, and add .gitignore for build targets. 2010-09-22 12:57:04 +02:00
analyze.c Make INSERT-from-multiple-VALUES-rows handle domain target columns. 2024-03-14 14:57:16 -04:00
check_keywords.pl Update copyright for 2021 2021-01-02 13:06:25 -05:00
gram.y Rename parser token REF to REF_P to avoid a symbol conflict. 2022-10-16 15:27:04 -04:00
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 Compute aggregate argument types correctly in transformAggregateCall(). 2023-11-06 10:38:00 -05:00
parse_clause.c Catch stack overflow when recursing in transformFromClauseItem(). 2022-08-13 15:21:28 -04:00
parse_coerce.c Fix failure to validate the result of select_common_type(). 2022-01-29 11:41:18 -05:00
parse_collate.c Update copyright for 2021 2021-01-02 13:06:25 -05:00
parse_cte.c Fix inability to reference CYCLE column from inside its CTE. 2022-12-16 13:07:42 -05:00
parse_enr.c Update copyright for 2021 2021-01-02 13:06:25 -05:00
parse_expr.c In transformRowExpr(), check for too many columns in the row. 2022-07-29 13:30:50 -04:00
parse_func.c Avoid O(N^2) behavior in SyncPostCheckpoint(). 2021-11-02 11:31:54 -04:00
parse_node.c In transformRowExpr(), check for too many columns in the row. 2022-07-29 13:30:50 -04:00
parse_oper.c Reconsider the handling of procedure OUT parameters. 2021-06-10 17:11:36 -04:00
parse_param.c Update copyright for 2021 2021-01-02 13:06:25 -05:00
parse_relation.c Fix type-checking of RECORD-returning functions in FROM, redux. 2024-04-15 12:56:56 -04:00
parse_target.c Make INSERT-from-multiple-VALUES-rows handle domain target columns. 2024-03-14 14:57:16 -04:00
parse_type.c Add the ability for the core grammar to have more than one parse target. 2021-01-04 11:03:22 -05:00
parse_utilcmd.c Fix handling of extended expression statistics in CREATE TABLE LIKE. 2024-05-22 17:54:17 -04:00
parser.c Re-implement pl/pgsql's expression and assignment parsing. 2021-01-04 11:52:00 -05:00
README Move keywords.c/kwlookup.c into src/common/. 2016-03-23 20:22:08 -04:00
scan.l Update copyright for 2021 2021-01-02 13:06:25 -05:00
scansup.c Update copyright for 2021 2021-01-02 13:06:25 -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.