Re: trouble with the automatic indexes on CREATE TABLE - Mailing list pgsql-general

From Bill McGonigle
Subject Re: trouble with the automatic indexes on CREATE TABLE
Date
Msg-id 200105161448.f4GEmhA14158@postgresql.org
Whole thread Raw
In response to Re: trouble with the automatic indexes on CREATE TABLE  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
Excellent.  Thanks.

There is one discussion of NAMEDATALEN in the archives, pertaining to
version 6.4.2.  That discussion brings up a few questions/assumptions
related to getting this to work reliably.  I'd love to hear any
comments/corrections/amplifications:

1) It was required that OIDNAMELEN be set to sizeof(Oid) + NAMEDATALEN.
Looking through the 7.1 source tree, OID_MAX is now set to UINT_MAX,
which should be plenty big. :)  Should I change anything else?

2) NAMEDATALEN is defined in the ODBC sources.  I found a message saying
this was used in the 6.2 protocol but not the 6.3 protocol - Is it safe to
assume it's not  used in the version 7 protocol either?  I'd hate to have
to dig out a Windows box to recompile the driver. ;)

3) Will psql from another machine fail to work if that machine's pgsql
hasn't been compiled with the modified MAXDATALEN?  Is this the same
question as (2)?

4) If 3 is yes, maybe negotiating MAXDATALEN in the protocol would be a
good idea?

5) If we assume equal lengths for table and column names (for the sake of
argument), when a UNIQUE constraint is present, the effective non-unique
length of a column name in pgsql, as distributed, is about 12 characters
(31-'__' -'__key')?  Isn't that kind of short?   If there is a replacement
for OIDNAMELEN, NAMEDATALEN could be set to 248 and both could still be
under 256 on a 64-bit machine.

I'm going to give it a whirl anyway - I just don't want to get stung later.

Thanks,
-Bill

On Tuesday, May 15, 2001, at 06:47 PM, Tom Lane wrote:

> If you want to use names like that, you'd be well advised to increase
> NAMEDATALEN.  See the archives.

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