Re: [HACKERS] Using multidimensional indexes in ordinal queries

2010-06-22 Thread Alexander Korotkov
On Tue, Jun 22, 2010 at 1:58 AM, Robert Haas robertmh...@gmail.com wrote: It doesn't? I didn't think it was making any assumptions about the ordering data type beyond the fact that it had a default btree opclass. Actually, the return type of consistent method was replaced by float8.

Re: [HACKERS] Using multidimensional indexes in ordinal queries

2010-06-21 Thread Thom Brown
On 6 June 2010 21:04, Alexander Korotkov aekorot...@gmail.com wrote: Hello hackers, I would like to share some my thoughts about usage of multidimensional indexes for queries which deal with ordinal unidimensional data types. I think that gist indexes (especially with knngist) can produce

Re: [HACKERS] Using multidimensional indexes in ordinal queries

2010-06-21 Thread Robert Haas
On Mon, Jun 21, 2010 at 5:19 AM, Thom Brown thombr...@gmail.com wrote: I can't answer this, but is anyone else able to provide Alexander some feedback? It seems like you can get more or less the same benefit from a multicolumn btree index. On my system, with the individual btree indices, the

Re: [HACKERS] Using multidimensional indexes in ordinal queries

2010-06-21 Thread Alexander Korotkov
On Mon, Jun 21, 2010 at 5:42 PM, Robert Haas robertmh...@gmail.com wrote: It seems like you can get more or less the same benefit from a multicolumn btree index. On my system, with the individual btree indices, the query ran in 7625 ms; with an additional index on (v1, v2, v3), it ran in 94

Re: [HACKERS] Using multidimensional indexes in ordinal queries

2010-06-21 Thread Robert Haas
On Mon, Jun 21, 2010 at 5:20 PM, Alexander Korotkov aekorot...@gmail.com wrote: 1) Make knngist deal with negative values. I think this will make easier using knngist just for sorting, not only k-neighbor searching. It doesn't? I didn't think it was making any assumptions about the ordering

[HACKERS] Using multidimensional indexes in ordinal queries

2010-06-07 Thread Alexander Korotkov
Hello hackers, I would like to share some my thoughts about usage of multidimensional indexes for queries which deal with ordinal unidimensional data types. I think that gist indexes (especially with knngist) can produce great benefit for complex multi-criterion queries. Let's consider come