RE: [HACKERS] Problem with query length

From: "Ansley, Michael" <Michael(dot)Ansley(at)intec(dot)co(dot)za>
To: "'Natalya S(dot) Makushina'" <mak(at)rtsoft(dot)msk(dot)ru>, "'pgsql-hackers(at)postgreSQL(dot)org'" <pgsql-hackers(at)postgresql(dot)org>
Subject: RE: [HACKERS] Problem with query length
Date: 1999-08-20 09:02:47
Message-ID: 1BF7C7482189D211B03F00805F8527F70ED115@S-NATH-EXCH2
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

To further this thread:

I have downloaded an example implementation of SQL which, thankfully, does
not use vltc's. I'm going to see where we have problems, and see if I can
reduce the scanner rules to something that is not variable-length trailing.

If anybody with significant scanner/language/parse experience (i.e. more
than mine == zero) has some pearls of wisdom to add, please feel free. I'm
a little out of my depth here, and I'm a bit nervous to go changing the
scanner.

MikeA

>> -----Original Message-----
>> From: Natalya S. Makushina [mailto:mak(at)rtsoft(dot)msk(dot)ru]
>> Sent: Thursday, August 19, 1999 10:39 AM
>> To: 'Ansley, Michael'; 'pgsql-hackers(at)postgreSQL(dot)org'
>> Subject: [HACKERS] Problem with query length
>>
>>
>> Hello
>>
>> Thank's very much for your help.
>>
>> I have already installed two copies of PostgreSQL DB. One
>> was installed from RPM, another one was compiled without
>> RPM. The copy installed from RPM has problem with query
>> length, another copy haven't this problem!
>>
>> I decide to compile it from sources and try to use. After
>> compilation all is OK! Query length is 8191 now.
>>
>> May be error presents in RPM.
>>
>> From : Ansley, Michael
>> [SMTP:Michael(dot)Ansley(at)intec(dot)co(dot)za]
>> Date : 18 августа 1999 г. 11:55
>> To : 'Natalya S. Makushina'; 'pgsql-hackers(at)postgreSQL(dot)org'
>> Subject : RE: [HACKERS] Problem with query length
>>
>> Hi, all
>>
>> I have found out what the problem is, although not (yet) the
>> solution.
>>
>> Executive summary:
>> ------------------
>> The scan.l code is not flexing as intended. This means
>> that, for most
>> production installations, the max token size is around 64kB.
>>
>> Technical summary:
>> ------------------
>> The problem is that scan.l is compiling to scan.c with
>> YY_USES_REJECT being
>> defined. When YY_USES_REJECT is defined, the token buffer is NOT
>> expandable, and the parser will fail if expansion is
>> attempted. However,
>> YY_USES_REJECT should not be defined, and I'm trying to work
>> out why it is.
>> I have posted to the flex mailing list, and expect a reply
>> within the next
>> day or so.
>>
>> The bottom line:
>> ------------------
>> The token limit seems to be effectively the size of
>> YY_BUF_SIZE in scan.l,
>> until I submit a patch which should make it unlimited.
>>
>>
>> MikeA
>>
>> >> -----Original Message-----
>> >> From: Natalya S. Makushina [mailto:mak(at)rtsoft(dot)msk(dot)ru]
>> >> Sent: Tuesday, August 17, 1999 3:15 PM
>> >> To: 'pgsql-hackers(at)postgreSQL(dot)org'
>> >> Subject: [HACKERS] Problem with query length
>> >>
>> >>
>> >> -------------------------------------------------------------
>> >> ----------------------------------------------------------------
>> >> I have posted this mail to psql-general. But i didn't get
>> >> any answer yet.
>> >> -------------------------------------------------------------
>> >> ----------------------------------------------------------------
>> >>
>> >> When i had tried to insert into text field text (length
>> >> about 4000 chars), the backend have crashed with status 139.
>> >> This error is happened when the query length ( SQL query) is
>> >> more than 4095 chars. I am using PostgreSQL 6.4.2 on Linux.
>> >>
>> >> My questions are:
>> >> 1. Is there problem with text field or with length of SQL query?
>> >> 2. Would postgresql have any limits for SQL query length?
>> >> I checked the archives but only found references to the 8K
>> >> limit. Any help would be greatly appreciated.
>> >> Thanks for help
>> >> Natalya Makushina
>> >> mak(at)rtsoft(dot)msk(dot)ru
>> >>
>> >>
>>
>> ************
>> Check out "PostgreSQL Wearables" @ http://www.pgsql.com
>>

Browse pgsql-hackers by date

  From Date Subject
Next Message F.J. Cuberos 1999-08-20 09:26:16 Statement Triggers Patch
Previous Message Ansley, Michael 1999-08-20 08:56:09 RE: [HACKERS] Postgres' lexer