Re: [HACKERS] Creating Empty Index
On Sun, Nov 3, 2013 at 3:01 AM, Tom Lane wrote: > Michael Paquier writes: >> On Sat, Nov 2, 2013 at 10:28 PM, Andrew Dunstan wrote: >>> What exactly would be the point? Indexes are automatically maintained by >>> postgres. Something that isn't doesn't seem to me to qualify for the >>> description of "index". > >> Perhaps an index without data that could be used by the planner for >> automatic query tuning to evaluate how a query could run if the index >> exists? Like the concept of hypothetical indexes or something like the >> possibility to do a CREATE/ALTER INDEX ... WITH [ NO ] DATA. > > But we already provide support for hypothetical indexes via planner > plugins. Why would you need an actual empty index underlying that? Using only the planner hook? Forgive my lack of knowledge of the planner, but this does not seem really straight-forward :) One of the only documentation I found about hypothetical indexes was this tutorial of PGCon 2010: http://www.inf.puc-rio.br/~postgresql/conteudo/projeto1/Tutorial9/TUTORIAL_9_0_1.pdf But in this case the grammar of CREATE INDEX has been modified, so core code was changed as well. Of course if Naman has something else in mind... -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Creating Empty Index
Michael Paquier writes: > On Sat, Nov 2, 2013 at 10:28 PM, Andrew Dunstan wrote: >> What exactly would be the point? Indexes are automatically maintained by >> postgres. Something that isn't doesn't seem to me to qualify for the >> description of "index". > Perhaps an index without data that could be used by the planner for > automatic query tuning to evaluate how a query could run if the index > exists? Like the concept of hypothetical indexes or something like the > possibility to do a CREATE/ALTER INDEX ... WITH [ NO ] DATA. But we already provide support for hypothetical indexes via planner plugins. Why would you need an actual empty index underlying that? I agree with Andrew that the use-case for this hasn't been explained. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Creating Empty Index
On Sat, Nov 2, 2013 at 10:28 PM, Andrew Dunstan wrote: > What exactly would be the point? Indexes are automatically maintained by > postgres. Something that isn't doesn't seem to me to qualify for the > description of "index". Perhaps an index without data that could be used by the planner for automatic query tuning to evaluate how a query could run if the index exists? Like the concept of hypothetical indexes or something like the possibility to do a CREATE/ALTER INDEX ... WITH [ NO ] DATA. -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Creating Empty Index
On 11/01/2013 02:11 AM, naman.iitb wrote: Hello Is there a way by which we can create an empty index on a relation and later fill it manually by inserting tuples. I want to know how it can be done in Postgresql code. Thanks in advance What exactly would be the point? Indexes are automatically maintained by postgres. Something that isn't doesn't seem to me to qualify for the description of "index". cheers andrew -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
