Search Postgresql Archives

GIN multi-column index

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi,

 

I’ve been looking at using GIN indices in some of my tables and was wondering something about their behavior when using them as a multi-column index. Suppose we have a table ‘t’ with column ‘a’ as int and column ‘b’ as int[]. Suppose we also have a query like:

select * from t where a=1 and b@>’{2}’

If I define a GIN index on (a, b) (with contrib extension btree_gin), will this be a significant improvement over a GIN index just on b (significant meaning, a similar improvement to what you would expect for a btree multi-column index in a similar situation where the equality is tested on first column and the second column is an inequality)? I know in a btree index the speedup is generally significant as long as your left-most index column has an equality comparison, due to the way btree indices work. But I couldn’t find information in the docs on how GIN indices behave in such a situation and why.

 

-Floris


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]

  Powered by Linux