I have two tables, one contains a large list of IDs and Info regarding those ids.
I have a second table Graph which just has two columns, each column contains the aforementioned id numbers, multiple times. I want to trim the size of my Info table by selecting only those ids that appear in my graph and creating a new smaller Info table. Is there a simple way of doing this?
CREATE TABLE FROM SELECT?
Thanks!
It's as easy as:
create table new_table
as
select t1.col1, t2.col2
from some_table t1
join t2 on t1.id = t2.some_id;
You can use any select statement for that. The column names of the new table are defined by the column aliases used in th query.
More details in the manual: http://www.postgresql.org/docs/current/static/sql-createtableas.html
You can create TEMP table if you need those small table only for that session. you can use below query to do that.
DROP TABLE IF EXISTS temp_table;
CREATE TEMP TABLE temp_table AS
SELECT
i.id as info_id, i.information as information
FROM
info i
INNER JOIN graph g ON i.id = g.id;
Now you can use this temp_table for your next table in the function.
OR
you can also create table like below (if you not want to create it as TEMP):
CREATE TABLE temp_table AS
SELECT
i.id as info_id, i.information as information
FROM
info i
INNER JOIN graph g ON i.id = g.id;
