I would like to know if there are any oracle equivalent of
dbms_mview.estimate_mview_size in Postgres as we have been using it
in Oracle for estimating required size for the upcoming mviews but
after migration to Postgres we find it very hard to estimate the
size.. Sometime our rds ran out of space and we had to spend lot of
efforts and time to bring back the rds once after rds storage is
exhausted. Or is there any other options available which can be used
to estimate the size.
A very rough estimation could be to use pg_column_size() on the rows of your SELECT statement and aggregate that.
Despite it's name pg_column_size() also calculates the size of a complete row.
select sum(pg_column_size(mv))
from (
.... your select statement here ...
) mv;
