I'd appreciate advice anyone can offer on this simple, newbie
question. It really is a straightforward question, so please bare with
me if I don't explain it succinctly below.
I want to search a table based on criteria on both a column within
that table and a column within a joined table, and I'm trying to
figure out how to index things for my particular form of query. The
postgres manual is excellent, but it doesn't appear to answer this
question explicitly through a matching example, and I'm not very good
with indexing, so I'm seeking advice here (yet again).
E.g. Suppose I have 2 tables defined:
CREATE TABLE table1 (
id SERIAL PRIMARY KEY,
CREATE TABLE table2 (
table1_id integer REFERENCES table1 ON DELETE CASCADE
My queries upon these tables are, almost exclusively, asking for all
the records with a particular 'name' between a range of times 't', and
so are of the form:
SELECT table2.x, table2.y, table2.t
FROM table2, table1
table2.table1_id = table1.id -- inner join
AND table1.name = 'some_name' -- criterion on table1
AND table2.t BETWEEN some_t AND some_other_t; --criterion on table2
What columns should I index in table2, and how: multi-column on
(table1_id, t), say, or multiple single column indexes, or only one
I guess the query might benefit from an index on table1's 'name'
column, but since there are, typically, only tens or hundreds of
records in table1, it might not be worth it. There are millions of
records in table2.
pgsql-novice by date
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