Calculate storage size of rows?

Question

In a multi-tenant only one DB, one column is used to isolate customers data, that is customer_id.

Is it possible to get the storage size of a certain customer in all tables?

score 10 · Accepted Answer · 2017-03-14T11:49:29.197

10

You can use pg_column_size() to get the size of a complete row, not only for a single column.

So to find the size of all rows for a specific customer, you can use something like this:

select sum(pg_column_size(t) + 24) 
from the_table t
where customer_id = 42;

(The 24 is the storage overhead per row in a table)

You would need to do that for all tables you are interested in.

This does however not include the size of those rows in the indexes.

edited Mar 14 '17 at 11:49

answered Mar 14 '17 at 10:41

Do you mean that the size of indexes is not retrieved? – simo Mar 14 '17 at 10:51
@simo: correct, that query does not include the size of indexed columns. – Mar 14 '17 at 10:55
is there any workaround to get indexed columns too? – simo Mar 14 '17 at 11:01
hands down the best way to do this Erwin's way here – Evan Carroll Mar 14 '17 at 14:59

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