2011/3/15 Robert Haas <robertmh...@gmail.com>:
> On Tue, Mar 15, 2011 at 2:19 AM, Pavel Stehule <pavel.steh...@gmail.com>
> wrote:
>> 2011/3/15 Robert Haas <robertmh...@gmail.com>:
>>> On Mon, Mar 14, 2011 at 4:34 PM, Tom Lane <t...@sss.pgh.pa.us> wrote:
>>>> Pavel Stehule <pavel.steh...@gmail.com> writes:
>>>>> there was a discussion about impact of number of keyword for parser
>>>>> speed. I did some synthetic tests and I didn't see any slowness on
>>>>> pgbench when I increased a number of keywords.
>>>>
>>>> I don't see any particular reason to suppose that pgbench would be a
>>>> good framework for stressing parsing speed. The queries it issues
>>>> are of trivial length.
>>>
>>> I found that it was actually a fairly measurable component of the
>>> select-only test when running with shared_buffers cranked up to a
>>> reasonable value. But it'd probably be a lot easier to measure on a
>>> benchmark specifically targeted at the parser.
>>>
>>
>> When I tested it - all data was in memory, there was a minimal (near
>> zero IO) and I run read only test.
>>
>> It doesn't mean, so parser is gratis, but my numbers doesn't show any
>> potential problem with 60 new keywords.
>
> That's an interesting result, although it would be more interesting if
> you posted the patch and benchmark methodology. It's important for us
> not to overestimate the cost of adding keywords, and I don't object to
> adding them where it adds meaningful clarity that is not otherwise
> available or where it is necessary to comply with the SQL spec. But I
> do think it is worth being disciplined about. We should think about
> wording commands in a way that won't require new keywords; if there's
> not a reasonable way to do it, then we add a keyword. Our preference
> should be not to add keywords where that's reasonably possible.
>
> It is particularly important for us to avoid keywords that are
> partially or fully reserved. In that case, the issue is not parser
> overhead but the fact that it breaks compatibility with previous
> releases. pg_dump files can't be loaded, PL/pgsql procedures break,
> and so on. I have been here and it isn't fun.
>
I agree and I understand well a problems with keywords. Just I would
to know a real limits of bison and I can say so 60 keywords are not a
problem.
Real test of parser's speed should be done on short and quick queries.
It can be unexpected so parser should be a bottle neck on long OLAP
queries.
Patch is added
Pavel
p.s. I am sure so this test depends on platform.
> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company
>
*** ./src/backend/parser/gram.y.orig 2011-03-15 17:01:59.000000000 +0100
--- ./src/backend/parser/gram.y 2011-03-14 20:54:02.000000000 +0100
***************
*** 568,573 ****
--- 568,585 ----
ZONE
+ AAAAAA AAABBB ABBBBB BAAAAA BAAAAB BAAABB
+ CAAAAA CAAAAC CAAACC DAAAAA DAAAAD DAAADD
+ IAAAAA IAAAAI IAAAII IAAIII IAIIII NAAAAA
+ NAAAAN NAAANN SAAAAA SAAAAS SAAASS SAASSS
+ SASSSS VAAAAA VAAAAV VAAAVV VAAVVV VABVVV
+
+ EAAAAA EAAAAE EAAAEE EAAEEE FAAAAA FAAAAF
+ FAAAFF FAAFFF OAAAAA OAAAAO OAAAOO OAAOOO
+ TAAAAA TAAAAT TAAATT TAATTT TATTTT UAAAAA
+ UAAAAU UAAAUU UAAUUU WAAAAA WAAAAW WAAAWW
+ WAAWWW WAWWWW XAAAAA XAAAAX XAAAXX XAAXXX
+
/*
* The grammar thinks these are keywords, but they are not in the kwlist.h
* list and so can never be entered directly. The filter in parser.c
***************
*** 12071,12076 ****
--- 12083,12119 ----
| YEAR_P
| YES_P
| ZONE
+
+ | EAAAAA
+ | EAAAAE
+ | EAAAEE
+ | EAAEEE
+ | FAAAAA
+ | FAAAAF
+ | FAAAFF
+ | FAAFFF
+ | OAAAAA
+ | OAAAAO
+ | OAAAOO
+ | OAAOOO
+ | TAAAAA
+ | TAAAAT
+ | TAAATT
+ | TAATTT
+ | TATTTT
+ | UAAAAA
+ | UAAAAU
+ | UAAAUU
+ | UAAUUU
+ | WAAAAA
+ | WAAAAW
+ | WAAAWW
+ | WAAWWW
+ | WAWWWW
+ | XAAAAA
+ | XAAAAX
+ | XAAAXX
+ | XAAXXX
;
/* Column identifier --- keywords that can be column, table, etc names.
***************
*** 12251,12256 ****
--- 12294,12330 ----
| WHERE
| WINDOW
| WITH
+
+ | AAAAAA
+ | AAABBB
+ | ABBBBB
+ | BAAAAA
+ | BAAAAB
+ | BAAABB
+ | CAAAAA
+ | CAAAAC
+ | CAAACC
+ | DAAAAA
+ | DAAAAD
+ | DAAADD
+ | IAAAAA
+ | IAAAAI
+ | IAAAII
+ | IAAIII
+ | IAIIII
+ | NAAAAA
+ | NAAAAN
+ | NAAANN
+ | SAAAAA
+ | SAAAAS
+ | SAAASS
+ | SAASSS
+ | SASSSS
+ | VAAAAA
+ | VAAAAV
+ | VAAAVV
+ | VAAVVV
+ | VABVVV
;
%%
*** ./src/include/parser/kwlist.h.orig 2011-03-15 17:00:33.207733416 +0100
--- ./src/include/parser/kwlist.h 2011-03-14 20:49:53.000000000 +0100
***************
*** 26,31 ****
--- 26,34 ----
*/
/* name, value, category */
+ PG_KEYWORD("aaaaaa", AAAAAA, RESERVED_KEYWORD)
+ PG_KEYWORD("aaabbb", AAABBB, RESERVED_KEYWORD)
+ PG_KEYWORD("abbbbb", ABBBBB, RESERVED_KEYWORD)
PG_KEYWORD("abort", ABORT_P, UNRESERVED_KEYWORD)
PG_KEYWORD("absolute", ABSOLUTE_P, UNRESERVED_KEYWORD)
PG_KEYWORD("access", ACCESS, UNRESERVED_KEYWORD)
***************
*** 51,56 ****
--- 54,62 ----
PG_KEYWORD("at", AT, UNRESERVED_KEYWORD)
PG_KEYWORD("attribute", ATTRIBUTE, UNRESERVED_KEYWORD)
PG_KEYWORD("authorization", AUTHORIZATION, TYPE_FUNC_NAME_KEYWORD)
+ PG_KEYWORD("baaaaa", BAAAAA, RESERVED_KEYWORD)
+ PG_KEYWORD("baaaab", BAAAAB, RESERVED_KEYWORD)
+ PG_KEYWORD("baaabb", BAAABB, RESERVED_KEYWORD)
PG_KEYWORD("backward", BACKWARD, UNRESERVED_KEYWORD)
PG_KEYWORD("before", BEFORE, UNRESERVED_KEYWORD)
PG_KEYWORD("begin", BEGIN_P, UNRESERVED_KEYWORD)
***************
*** 61,66 ****
--- 67,75 ----
PG_KEYWORD("boolean", BOOLEAN_P, COL_NAME_KEYWORD)
PG_KEYWORD("both", BOTH, RESERVED_KEYWORD)
PG_KEYWORD("by", BY, UNRESERVED_KEYWORD)
+ PG_KEYWORD("caaaaa", CAAAAA, RESERVED_KEYWORD)
+ PG_KEYWORD("caaaac", CAAAAC, RESERVED_KEYWORD)
+ PG_KEYWORD("caaacc", CAAACC, RESERVED_KEYWORD)
PG_KEYWORD("cache", CACHE, UNRESERVED_KEYWORD)
PG_KEYWORD("called", CALLED, UNRESERVED_KEYWORD)
PG_KEYWORD("cascade", CASCADE, UNRESERVED_KEYWORD)
***************
*** 111,116 ****
--- 120,128 ----
PG_KEYWORD("current_user", CURRENT_USER, RESERVED_KEYWORD)
PG_KEYWORD("cursor", CURSOR, UNRESERVED_KEYWORD)
PG_KEYWORD("cycle", CYCLE, UNRESERVED_KEYWORD)
+ PG_KEYWORD("daaaaa", DAAAAA, RESERVED_KEYWORD)
+ PG_KEYWORD("daaaad", DAAAAD, RESERVED_KEYWORD)
+ PG_KEYWORD("daaadd", DAAADD, RESERVED_KEYWORD)
PG_KEYWORD("data", DATA_P, UNRESERVED_KEYWORD)
PG_KEYWORD("database", DATABASE, UNRESERVED_KEYWORD)
PG_KEYWORD("day", DAY_P, UNRESERVED_KEYWORD)
***************
*** 136,141 ****
--- 148,157 ----
PG_KEYWORD("domain", DOMAIN_P, UNRESERVED_KEYWORD)
PG_KEYWORD("double", DOUBLE_P, UNRESERVED_KEYWORD)
PG_KEYWORD("drop", DROP, UNRESERVED_KEYWORD)
+ PG_KEYWORD("eaaaaa", EAAAAA, UNRESERVED_KEYWORD)
+ PG_KEYWORD("eaaaae", EAAAAE, UNRESERVED_KEYWORD)
+ PG_KEYWORD("eaaaee", EAAAEE, UNRESERVED_KEYWORD)
+ PG_KEYWORD("eaaeee", EAAEEE, UNRESERVED_KEYWORD)
PG_KEYWORD("each", EACH, UNRESERVED_KEYWORD)
PG_KEYWORD("else", ELSE, RESERVED_KEYWORD)
PG_KEYWORD("enable", ENABLE_P, UNRESERVED_KEYWORD)
***************
*** 154,159 ****
--- 170,179 ----
PG_KEYWORD("extension", EXTENSION, UNRESERVED_KEYWORD)
PG_KEYWORD("external", EXTERNAL, UNRESERVED_KEYWORD)
PG_KEYWORD("extract", EXTRACT, COL_NAME_KEYWORD)
+ PG_KEYWORD("faaaaa", FAAAAA, UNRESERVED_KEYWORD)
+ PG_KEYWORD("faaaaf", FAAAAF, UNRESERVED_KEYWORD)
+ PG_KEYWORD("faaaff", FAAAFF, UNRESERVED_KEYWORD)
+ PG_KEYWORD("faafff", FAAFFF, UNRESERVED_KEYWORD)
PG_KEYWORD("false", FALSE_P, RESERVED_KEYWORD)
PG_KEYWORD("family", FAMILY, UNRESERVED_KEYWORD)
PG_KEYWORD("fetch", FETCH, RESERVED_KEYWORD)
***************
*** 179,184 ****
--- 199,209 ----
PG_KEYWORD("header", HEADER_P, UNRESERVED_KEYWORD)
PG_KEYWORD("hold", HOLD, UNRESERVED_KEYWORD)
PG_KEYWORD("hour", HOUR_P, UNRESERVED_KEYWORD)
+ PG_KEYWORD("iaaaaa", IAAAAA, RESERVED_KEYWORD)
+ PG_KEYWORD("iaaaai", IAAAAI, RESERVED_KEYWORD)
+ PG_KEYWORD("iaaaii", IAAAII, RESERVED_KEYWORD)
+ PG_KEYWORD("iaaiii", IAAIII, RESERVED_KEYWORD)
+ PG_KEYWORD("iaiiii", IAIIII, RESERVED_KEYWORD)
PG_KEYWORD("identity", IDENTITY_P, UNRESERVED_KEYWORD)
PG_KEYWORD("if", IF_P, UNRESERVED_KEYWORD)
PG_KEYWORD("ilike", ILIKE, TYPE_FUNC_NAME_KEYWORD)
***************
*** 239,244 ****
--- 264,272 ----
PG_KEYWORD("mode", MODE, UNRESERVED_KEYWORD)
PG_KEYWORD("month", MONTH_P, UNRESERVED_KEYWORD)
PG_KEYWORD("move", MOVE, UNRESERVED_KEYWORD)
+ PG_KEYWORD("naaaaa", NAAAAA, RESERVED_KEYWORD)
+ PG_KEYWORD("naaaan", NAAAAN, RESERVED_KEYWORD)
+ PG_KEYWORD("naaann", NAAANN, RESERVED_KEYWORD)
PG_KEYWORD("name", NAME_P, UNRESERVED_KEYWORD)
PG_KEYWORD("names", NAMES, UNRESERVED_KEYWORD)
PG_KEYWORD("national", NATIONAL, COL_NAME_KEYWORD)
***************
*** 263,268 ****
--- 291,300 ----
PG_KEYWORD("nullif", NULLIF, COL_NAME_KEYWORD)
PG_KEYWORD("nulls", NULLS_P, UNRESERVED_KEYWORD)
PG_KEYWORD("numeric", NUMERIC, COL_NAME_KEYWORD)
+ PG_KEYWORD("oaaaaa", OAAAAA, UNRESERVED_KEYWORD)
+ PG_KEYWORD("oaaaao", OAAAAO, UNRESERVED_KEYWORD)
+ PG_KEYWORD("oaaaoo", OAAAOO, UNRESERVED_KEYWORD)
+ PG_KEYWORD("oaaooo", OAAOOO, UNRESERVED_KEYWORD)
PG_KEYWORD("object", OBJECT_P, UNRESERVED_KEYWORD)
PG_KEYWORD("of", OF, UNRESERVED_KEYWORD)
PG_KEYWORD("off", OFF, UNRESERVED_KEYWORD)
***************
*** 329,334 ****
--- 361,371 ----
PG_KEYWORD("row", ROW, COL_NAME_KEYWORD)
PG_KEYWORD("rows", ROWS, UNRESERVED_KEYWORD)
PG_KEYWORD("rule", RULE, UNRESERVED_KEYWORD)
+ PG_KEYWORD("saaaaa", SAAAAA, RESERVED_KEYWORD)
+ PG_KEYWORD("saaaas", SAAAAS, RESERVED_KEYWORD)
+ PG_KEYWORD("saaass", SAAASS, RESERVED_KEYWORD)
+ PG_KEYWORD("saasss", SAASSS, RESERVED_KEYWORD)
+ PG_KEYWORD("sassss", SASSSS, RESERVED_KEYWORD)
PG_KEYWORD("savepoint", SAVEPOINT, UNRESERVED_KEYWORD)
PG_KEYWORD("schema", SCHEMA, UNRESERVED_KEYWORD)
PG_KEYWORD("scroll", SCROLL, UNRESERVED_KEYWORD)
***************
*** 365,370 ****
--- 402,412 ----
PG_KEYWORD("symmetric", SYMMETRIC, RESERVED_KEYWORD)
PG_KEYWORD("sysid", SYSID, UNRESERVED_KEYWORD)
PG_KEYWORD("system", SYSTEM_P, UNRESERVED_KEYWORD)
+ PG_KEYWORD("taaaaa", TAAAAA, UNRESERVED_KEYWORD)
+ PG_KEYWORD("taaaat", TAAAAT, UNRESERVED_KEYWORD)
+ PG_KEYWORD("taaatt", TAAATT, UNRESERVED_KEYWORD)
+ PG_KEYWORD("taattt", TAATTT, UNRESERVED_KEYWORD)
+ PG_KEYWORD("tatttt", TATTTT, UNRESERVED_KEYWORD)
PG_KEYWORD("table", TABLE, RESERVED_KEYWORD)
PG_KEYWORD("tables", TABLES, UNRESERVED_KEYWORD)
PG_KEYWORD("tablespace", TABLESPACE, UNRESERVED_KEYWORD)
***************
*** 385,390 ****
--- 427,436 ----
PG_KEYWORD("truncate", TRUNCATE, UNRESERVED_KEYWORD)
PG_KEYWORD("trusted", TRUSTED, UNRESERVED_KEYWORD)
PG_KEYWORD("type", TYPE_P, UNRESERVED_KEYWORD)
+ PG_KEYWORD("uaaaaa", UAAAAA, UNRESERVED_KEYWORD)
+ PG_KEYWORD("uaaaau", UAAAAU, UNRESERVED_KEYWORD)
+ PG_KEYWORD("uaaauu", UAAAUU, UNRESERVED_KEYWORD)
+ PG_KEYWORD("uaauuu", UAAUUU, UNRESERVED_KEYWORD)
PG_KEYWORD("unbounded", UNBOUNDED, UNRESERVED_KEYWORD)
PG_KEYWORD("uncommitted", UNCOMMITTED, UNRESERVED_KEYWORD)
PG_KEYWORD("unencrypted", UNENCRYPTED, UNRESERVED_KEYWORD)
***************
*** 397,402 ****
--- 443,453 ----
PG_KEYWORD("update", UPDATE, UNRESERVED_KEYWORD)
PG_KEYWORD("user", USER, RESERVED_KEYWORD)
PG_KEYWORD("using", USING, RESERVED_KEYWORD)
+ PG_KEYWORD("vaaaaa", VAAAAA, RESERVED_KEYWORD)
+ PG_KEYWORD("vaaaav", VAAAAV, RESERVED_KEYWORD)
+ PG_KEYWORD("vaaavv", VAAAVV, RESERVED_KEYWORD)
+ PG_KEYWORD("vaavvv", VAAVVV, RESERVED_KEYWORD)
+ PG_KEYWORD("vabvvv", VABVVV, RESERVED_KEYWORD)
PG_KEYWORD("vacuum", VACUUM, UNRESERVED_KEYWORD)
PG_KEYWORD("valid", VALID, UNRESERVED_KEYWORD)
PG_KEYWORD("validate", VALIDATE, UNRESERVED_KEYWORD)
***************
*** 410,415 ****
--- 461,471 ----
PG_KEYWORD("version", VERSION_P, UNRESERVED_KEYWORD)
PG_KEYWORD("view", VIEW, UNRESERVED_KEYWORD)
PG_KEYWORD("volatile", VOLATILE, UNRESERVED_KEYWORD)
+ PG_KEYWORD("waaaaa", WAAAAA, UNRESERVED_KEYWORD)
+ PG_KEYWORD("waaaaw", WAAAAW, UNRESERVED_KEYWORD)
+ PG_KEYWORD("waaaww", WAAAWW, UNRESERVED_KEYWORD)
+ PG_KEYWORD("waawww", WAAWWW, UNRESERVED_KEYWORD)
+ PG_KEYWORD("wawwww", WAWWWW, UNRESERVED_KEYWORD)
PG_KEYWORD("when", WHEN, RESERVED_KEYWORD)
PG_KEYWORD("where", WHERE, RESERVED_KEYWORD)
PG_KEYWORD("whitespace", WHITESPACE_P, UNRESERVED_KEYWORD)
***************
*** 419,424 ****
--- 475,484 ----
PG_KEYWORD("work", WORK, UNRESERVED_KEYWORD)
PG_KEYWORD("wrapper", WRAPPER, UNRESERVED_KEYWORD)
PG_KEYWORD("write", WRITE, UNRESERVED_KEYWORD)
+ PG_KEYWORD("xaaaaa", XAAAAA, UNRESERVED_KEYWORD)
+ PG_KEYWORD("xaaaax", XAAAAX, UNRESERVED_KEYWORD)
+ PG_KEYWORD("xaaaxx", XAAAXX, UNRESERVED_KEYWORD)
+ PG_KEYWORD("xaaxxx", XAAXXX, UNRESERVED_KEYWORD)
PG_KEYWORD("xml", XML_P, UNRESERVED_KEYWORD)
PG_KEYWORD("xmlattributes", XMLATTRIBUTES, COL_NAME_KEYWORD)
PG_KEYWORD("xmlconcat", XMLCONCAT, COL_NAME_KEYWORD)
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