postgresql

History

Tomas Vondra 31f3817402 Allow COPY FROM to filter data using WHERE conditions Extends the COPY FROM command with a WHERE condition, which allows doing various types of filtering while importing the data (random sampling, condition on a data column, etc.). Until now such filtering required either preprocessing of the input data, or importing all data and then filtering in the database. COPY FROM ... WHERE is an easy-to-use and low-overhead alternative for most simple cases. Author: Surafel Temesgen Reviewed-by: Tomas Vondra, Masahiko Sawada, Lim Myungkyu Discussion: https://www.postgresql.org/message-id/flat/CALAY4q_DdpWDuB5-Zyi-oTtO2uSk8pmy+dupiRe3AvAc++1imA@mail.gmail.com		2019-01-20 00:22:14 +01:00
..
.gitignore	Convert cvsignore to gitignore, and add .gitignore for build targets.	2010-09-22 12:57:04 +02:00
Makefile	Revert MERGE patch	2018-04-12 11:22:56 +01:00
README	Move keywords.c/kwlookup.c into src/common/.	2016-03-23 20:22:08 -04:00
analyze.c	Postpone aggregate checks until after collation is assigned.	2019-01-17 06:46:10 +00:00
check_keywords.pl	Update copyright for 2019	2019-01-02 12:44:25 -05:00
gram.y	Allow COPY FROM to filter data using WHERE conditions	2019-01-20 00:22:14 +01:00
parse_agg.c	Allow COPY FROM to filter data using WHERE conditions	2019-01-20 00:22:14 +01:00
parse_clause.c	Update copyright for 2019	2019-01-02 12:44:25 -05:00
parse_coerce.c	Update copyright for 2019	2019-01-02 12:44:25 -05:00
parse_collate.c	Update copyright for 2019	2019-01-02 12:44:25 -05:00
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	Allow COPY FROM to filter data using WHERE conditions	2019-01-20 00:22:14 +01:00
parse_func.c	Allow COPY FROM to filter data using WHERE conditions	2019-01-20 00:22:14 +01:00
parse_node.c	Update copyright for 2019	2019-01-02 12:44:25 -05:00
parse_oper.c	Update copyright for 2019	2019-01-02 12:44:25 -05:00
parse_param.c	Update copyright for 2019	2019-01-02 12:44:25 -05:00
parse_relation.c	Don't include heapam.h from others headers.	2019-01-14 16:24:41 -08:00
parse_target.c	Update copyright for 2019	2019-01-02 12:44:25 -05:00
parse_type.c	Update copyright for 2019	2019-01-02 12:44:25 -05:00
parse_utilcmd.c	Don't include heapam.h from others headers.	2019-01-14 16:24:41 -08:00
parser.c	Replace the data structure used for keyword lookup.	2019-01-06 17:02:57 -05:00
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

README

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.