Snapshot Materialized Views - GSoC
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From: Jaime Casanova on 20 May 2010 13:35 2010/5/20 Pavel <baros.p(a)seznam.cz>: > > d) what to do when someone use INSERT, UPDATE or DELETE against MV? >  1 - raise error? - I prefer this option +1, FWIW >  2 - let commands change MV? (no chance to let changes propagate to > source tables, not for this summer :) >  if pg lets user to DML against MV, I expect that triggers should work too > no, if you don't propagate then you don't have a view of the tables the MV comes from... error if you'll not implement propagation now -- Jaime Casanova www.2ndQuadrant.com Soporte y capacitación de PostgreSQL -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Robert Haas on 21 May 2010 09:59 2010/5/20 Pavel <baros.p(a)seznam.cz>: > For this summer I have plan to make patch inplementing snapshot materialized > views (MV). I believe it will not be end of effort to implement more of MV. > But I / we need discuss MV syntax and exact behaviour so I have some > questions about that for all of you: > > a) relkind for materialized view in pg_class? > - I'm voting for char 'm' quite obvious why, but not sure about alias: > 1 - RELKIND_MVIEW > 2 - RELKIND_MATVIEW > or any other ideas? I think the prior question is whether we need to create a new relkind at all. I'm prepared to believe that the answer is yes, but I'd like to see a clear justification of why we can't use either 'v' or 'r'. It seems to me that a materialized view is a lot like a regular old table with a special rewrite rule attached to it somewhere. > b) create MV syntax? > - CREATE MATERIALIZED VIEW mvname AS ..., I think it is quite > obvious to do so, but I had to ask I think that's OK. > c) refresh command syntax? > 1 - ALTER MATERIALIZED VIEW mvname REFRESH > or > 2 - REFRESH MATERIALIZED VIEW mvname 1. > d) what to do when someone use INSERT, UPDATE or DELETE against MV? > 1 - raise error? - I prefer this option > 2 - let commands change MV? (no chance to let changes propagate to > source tables, not for this summer :) > if pg lets user to DML against MV, I expect that triggers should work too 1. > e) what to do when someone drop table or column? > - it behave like it was a classic view. Fire error and hint > - CASCADE option will remove MV Agree. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise Postgres Company -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: "Massa, Harald Armin" on 21 May 2010 10:02 Pavel, b) create MV syntax? > - CREATE MATERIALIZED VIEW mvname AS ..., I think it is quite > obvious to do so, but I had to ask > please do not fortget the: create or replace MATERIALIZED VIEW option. And also the DROP if exists for the drop-command Best wishes Harald -- GHUM Harald Massa persuadere et programmare Harald Armin Massa Spielberger StraÃe 49 70435 Stuttgart 0173/9409607 no fx, no carrier pigeon - Using PostgreSQL is mostly about sleeping well at night.
From: Tom Lane on 21 May 2010 10:13 "Massa, Harald Armin" <chef(a)ghum.de> writes: > please do not fortget the: > create or replace MATERIALIZED VIEW > option. Please do. For something as complex as a table or view, CREATE OR REPLACE is a lot more complicated than it is for simple objects like functions. (See flamewar just a couple weeks ago about C.O.R. vs CREATE IF NOT EXISTS for tables.) Putting this on the to-do list for the GSOC project will just about guarantee failure. It's most likely too large a task for a GSOC project already... regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Florian Pflug on 21 May 2010 10:31
On May 21, 2010, at 15:59 , Robert Haas wrote: > 2010/5/20 Pavel <baros.p(a)seznam.cz>: >> For this summer I have plan to make patch inplementing snapshot materialized >> views (MV). I believe it will not be end of effort to implement more of MV. >> But I / we need discuss MV syntax and exact behaviour so I have some >> questions about that for all of you: >> >> a) relkind for materialized view in pg_class? >> - I'm voting for char 'm' quite obvious why, but not sure about alias: >> 1 - RELKIND_MVIEW >> 2 - RELKIND_MATVIEW >> or any other ideas? > > I think the prior question is whether we need to create a new relkind > at all. I'm prepared to believe that the answer is yes, but I'd like > to see a clear justification of why we can't use either 'v' or 'r'. > It seems to me that a materialized view is a lot like a regular old > table with a special rewrite rule attached to it somewhere. I guess the justification is that with the same argument you could argue that a view should have relkind 'r', since it's just an empty table with a rewrite rule attached. I think relkind is mostly there to make pg_dump's and the information schema's job easier - without it, distinguishing tables with ON SELECT rules from views seem rather AI-complete. The same holds for materialized views vs. tables and materialized views vs. views. best regards, Florian Pflug -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers |