Re: python patch - Mailing list pgsql-hackers
From | Christopher Kings-Lynne |
---|---|
Subject | Re: python patch |
Date | |
Msg-id | GNELIHDDFBOCMGBFGEFOKELFCDAA.chriskl@familyhealth.com.au Whole thread Raw |
In response to | Re: python patch (Greg Copeland <greg@CopelandConsulting.Net>) |
Responses |
Re: python patch
|
List | pgsql-hackers |
Yep - alright, just commit it I guess. Chris > -----Original Message----- > From: Greg Copeland [mailto:greg@copelandconsulting.net] > Sent: Thursday, 15 August 2002 11:09 AM > To: Rod Taylor > Cc: Christopher Kings-Lynne; Bruce Momjian; PostgresSQL Hackers Mailing > List > Subject: Re: [HACKERS] python patch > > > Well, I tend to agree with that. Overall, I can't say that I see bad > things coming out of accepting the patch as is. It's not exactly > causing an extra join or other wise a significant waste of resources. > At worst, it appears to be ambiguous. Since Christopher has not offered > any additional follow up, can we assume that he agrees? In not, please > let me know and I'll resubmit patch #2. > > In the mean time, patches #1 and #3 should be good to go. Bruce, feel > free to apply those whenever time allows. > > Thanks, > Greg Copeland > > > On Mon, 2002-08-12 at 18:33, Rod Taylor wrote: > > All of that said, the cost of the check is so small it may save someones > > ass some day when they have a corrupted catalog and the below > > assumptions are no longer true. > > > > On Mon, 2002-08-12 at 18:40, Greg Copeland wrote: > > > On Sun, 2002-08-11 at 21:15, Christopher Kings-Lynne wrote: > > > > > Not a problem. I would rather them be correct. > > > > > > > > > > Worth noting that the first patch is what attempts to fix > the long -> > > > > > int overflow issue. The second patch attempts to resolve > "attisdropped" > > > > > column use issues with the python scripts. The third > patch addresses > > > > > issues generated by the implicate to explicate use of "cascade". > > > > > > > > > > I assume your reservations are only with the second patch > and not the > > > > > first and third patches? > > > > > > > > Correct. I'm pretty sure you don't need to exclude > attisdropped from the > > > > primary key list because all it's doing is finding the > column that a primary > > > > key is over and that should never be over a dropped column. I can't > > > > remember what you said the second query did? > > > > > > > > > Hmmm. Sounds okay but I'm just not sure that holds true (as I > > > previously stated, I'm ignorant on the topic). Obviously > I'll defer to > > > you on this. > > > > > > Here's the queries and what they do: > > > > > > > > > >From pg.py: > > > Used to locate primary keys -- or so the comment says. It > does create a > > > dictionary of keys and attribute values for each returned row so I > > > assume it really is attempting to do something of the like. > > > > > > SELECT pg_class.relname, pg_attribute.attname > > > FROM pg_class, pg_attribute, pg_index > > > WHERE pg_class.oid = pg_attribute.attrelid AND > > > pg_class.oid = pg_index.indrelid AND > > > pg_index.indkey[0] = pg_attribute.attnum AND > > > pg_index.indisprimary = 't' AND > > > pg_attribute.attisdropped = 'f' ; > > > > > > So, everyone is in agreement that any attribute which is indexed as a > > > primary key will never be able to have attisdtopped = 't'? > > > > > > According to the code: > > > SELECT pg_attribute.attname, pg_type.typname > > > FROM pg_class, pg_attribute, pg_type > > > WHERE pg_class.relname = '%s' AND > > > pg_attribute.attnum > 0 AND > > > pg_attribute.attrelid = pg_class.oid AND > > > pg_attribute.atttypid = pg_type.oid AND > > > pg_attribute.attisdropped = 'f' ; > > > > > > is used to obtain all attributes (column names) and their types for a > > > given table ('%s'). It then attempts to build a column/type > cache. I'm > > > assuming that this really does need to be there. Please correct > > > accordingly. > > > > > > > > > >From syscat.py: > > > SELECT bc.relname AS class_name, > > > ic.relname AS index_name, a.attname > > > FROM pg_class bc, pg_class ic, pg_index i, pg_attribute a > > > WHERE i.indrelid = bc.oid AND i.indexrelid = bc.oid > > > AND i.indkey[0] = a.attnum AND a.attrelid = bc.oid > > > AND i.indproc = '0'::oid AND a.attisdropped = 'f' > > > ORDER BY class_name, index_name, attname ; > > > > > > According to the nearby documentation, it's supposed to be fetching a > > > list of "all simple indicies". If that's the case, is it > safe to assume > > > that any indexed column will never have attisdropped = 't'? If so, we > > > can remove that check from the file as well. Worth pointing out, this > > > is from syscat.py, which is sample source and not used as actual > > > interface. So, worse case, it would appear to be redundant in nature > > > with no harm done. > > > > > > This should conclude the patched items offered in the second patch. > > > > > > What ya think? > > > > > > Thanks, > > > Greg > > > > > > > > > > > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org > >
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