I have a primary parent table with a child table per week of the year for each week back through 2015. There are a lot of child tables. Each week's child table has maybe 80-110m rows.
When I join to the parent table on a column, it's very slow, but when I manually specify the specific week's child table, it's quite fast, e.g.
Slow:
select * from foo
join schema.mytable on foo.col = mytable.col
vs. fast:
select * from foo
join schema.mytable_2015_wk33 as mytable on foo.col = mytable.col
What's the resolution to make querying the table faster in terms of it finding the appropriate child table? Is it putting an index on `col` on each child table? Some other thing?
Thank you.
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