2015-11-11 10:44 GMT+01:00 Dusan <fesz21@xxxxxxxxx>: > Hi, > I'm using table with parent_id to themselve and WITH RECURSIVE in SELECT on > about 3thousands records. > The "tree" of data is wide (each node has more children) but not deep > (maximal depth of branch is 10 nodes). > > I'm planning to use same schema on much deeper but narrower tree (most of > nodes will have only one child, only few nodes will have two or little bit > more childs). > It will represent points on map of line construction with many points > (nodes). It would have thousands of nodes, there will be more independent > trees (up to hundreds), some of them will be much smaller then others. Count > of nodes in table will be about few hundreds of thousands. > > Alternatively I can divide line constructions to many sections (from cross > of lines to other) and have it on separate table like this: > CREATE TABLE sections ( > id_section SERIAL PRIMARY KEY > ); > > CREATE TABLE section_nodes ( > id_node SERIAL PRIMARY KEY, > sections_id_section INTEGER REFERENCES sections (id_section), > x INTEGER, > y INTEGER, > sortid INTEGER -- serial number of onde in one section > ); > > Solution with recursive is nicer and easier for administration (and > SELECTing from it), but won't be problem with performance on so many > recursion? Is there some limitations of recursive tables? > Or is better solution the second one with seperated sections? > > Thanks for help and your opinion. > > Dusan > > > -- > Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general Hello, I don't get how your "section way" exactly works. What about closure tables ? http://karwin.blogspot.fr/2010/03/rendering-trees-with-closure-tables.html The performances are good -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
