[pgpool-committers: 5948] pgpool: Multiple performance enhancements especially for of the large

[Muhammad Usama]

Multiple performance enhancements especially for of the large
INSERT and UPDATE statements

Pgpool-II only needs very little information, especially for the INSERT and
UPDATE statements to decide where it needs to send the query.
For example: In master-slave mode, for the INSERT statements Pgpool-II only
requires the relation name referenced in the statement while it doesn't care
much about the column values and other parameters. But since the parser we use
in Pgpool-II is taken from PostgreSQL source which parses the complete query
including the value lists which seems harmless for smaller statements but in
case of INSERT and UPDATE with lots of column values and large data in value
items, consumes significant time.

So the idea here is to short circuit the INSERT and UPDATE statement parsing as
soon as we have the required information. For that purpose, the commit adds the
second minimal parser that gets invoked in master-slave mode and tries to
extract the performance for large INSERT and UPDATE statements.

Apart from the second parser addition, following changes aiming towards the
performance enhancements are also part of the commit.

1-Some of the if statements in pool_where_to_send() function are re-arranged to
make sure the more expensive functions calls, pattern_compare()
and pool_has_function_call() should only be made when they are
absolutely necessary.

2- Eliminates the raw_parser() calls in case of un-recognized queries. Instead
of invoking the parser on "dummy read" and "dummy write" statements, the commit
adds the functions to return the pre-built parse_trees for these dummy queries.

3-- strlen() call is removed from scanner_init() function and is passed to it
as an argument. The reason being we already have the query length in most cases
before invoking the parser so why waste CPU cycles on it. Again this becomes
significant in case of large query strings.

4- Removes some of the unnecessary calls of pool_is_likely_select() function.

Branch
------
master

Details
-------
https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=310c5c4a289cbe6cee01abef7d2e7bc3550944fb

Modified Files
--------------
Makefile.in                                        |     1 +
configure                                          |    59 +
configure.ac                                       |    12 +
doc.ja/Makefile.in                                 |     1 +
doc.ja/src/Makefile.in                             |     1 +
doc.ja/src/sgml/Makefile.in                        |     1 +
doc/Makefile.in                                    |     1 +
doc/src/Makefile.in                                |     1 +
doc/src/sgml/Makefile.in                           |     1 +
src/Makefile.in                                    |     1 +
src/context/pool_query_context.c                   |    42 +-
src/include/Makefile.in                            |     1 +
src/include/parser/gramparse.h                     |     6 +
src/include/parser/parser.h                        |     5 +-
src/include/parser/scanner.h                       |     1 +
src/include/protocol/pool_proto_modules.h          |     2 -
src/libs/Makefile.in                               |     1 +
src/libs/pcp/Makefile.in                           |     1 +
src/parser/Makefile.am                             |    10 +-
src/parser/Makefile.in                             |    37 +-
src/parser/README                                  |    49 +
src/parser/gram.c                                  |  3255 +-
src/parser/gram.y                                  |     7 +-
src/parser/gram_minimal.c                          | 46971 +++++++++++++++++++
src/parser/gram_minimal.h                          |  1053 +
src/parser/gram_minimal.y                          | 16403 +++++++
src/parser/gram_template.y                         | 16492 +++++++
src/parser/parser.c                                |    84 +-
src/parser/scan.c                                  |     2 +-
src/parser/scan.l                                  |     2 +-
src/protocol/pool_process_query.c                  |     2 +-
src/protocol/pool_proto_modules.c                  |    35 +-
.../tests/010.rewrite_timestamp/timestamp/main.c   |     2 +-
.../regression/tests/017.node_0_is_down/test.sh    |     4 +-
src/tools/Makefile.in                              |     1 +
src/tools/pcp/Makefile.in                          |     1 +
src/tools/pgenc/Makefile.in                        |     1 +
src/tools/pgmd5/Makefile.in                        |     1 +
src/tools/pgproto/Makefile.in                      |     1 +
src/watchdog/Makefile.in                           |     1 +
40 files changed, 82852 insertions(+), 1700 deletions(-)