Display another field in the referenced table for multiple columns with performance issues in mind

Posted by israkir on Stack Overflow See other posts from Stack Overflow or by israkir
Published on 2012-11-23T04:50:32Z Indexed on 2012/11/25 23:05 UTC
Read the original article Hit count: 212

Filed under:

sql

|

Performance

|

postgresql

|

index

|

bigdata

I have a table of edge like this:

-------------------------------
| id | arg1 | relation | arg2 |
-------------------------------
| 1  |   1  |     3    |   4  |
-------------------------------
| 2  |   2  |     6    |   5  |
-------------------------------

where arg1, relation and arg2 reference to the ids of objects in another object table:

--------------------
| id | object_name |
--------------------
| 1  |   book      |
--------------------
| 2  |   pen       |
--------------------
| 3  |   on        |
--------------------
| 4  |   table     |
--------------------
| 5  |   bag       |
--------------------
| 6  |   in        |
--------------------

What I want to do is that, considering performance issues (a very big table more than 50 million of entries) display the object_name for each edge entry rather than id such as:

---------------------------
| arg1 | relation | arg2  |
---------------------------
| book |    on    | table |
---------------------------
|  pen |    in    | bag   |
---------------------------

What is the best select query to do this? Also, I am open to suggestions for optimizing the query - adding more index on the tables etc...

EDIT: Based on the comments below:

1) @Craig Ringer: PostgreSQL version: 8.4.13 and only index is id for both tables.

2) @andrefsp: edge is almost x2 times bigger than object.

Developer IT