Обсуждение: Support for Physical Column Reordering in PG
Hi,is there any better way to change the order of a column except
1) creating a new table and do insert with select with rearranged columns
2) using views
use case:
there are cases where we might be using delta compression between tuples we have a table like
"create table temp(x bigint,y char(3),z integer);"
If we have tuple values,for the column y less than 3, SQL standard does padding to make the length = 3,which causes delta noise,so to reduce this noise we reposition the column y at the end ,which helps us to reduce the delta between tuples.
So is making a patch to have a sql command to reposition the column like other databases makes sense? thoughts ?
1) creating a new table and do insert with select with rearranged columns
2) using views
use case:
there are cases where we might be using delta compression between tuples we have a table like
"create table temp(x bigint,y char(3),z integer);"
If we have tuple values,for the column y less than 3, SQL standard does padding to make the length = 3,which causes delta noise,so to reduce this noise we reposition the column y at the end ,which helps us to reduce the delta between tuples.
So is making a patch to have a sql command to reposition the column like other databases makes sense? thoughts ?
Srinath Reddy Sadipiralla <srinath2133@gmail.com> writes:
> So is making a patch to have a sql command to reposition the column like
> other databases makes sense? thoughts ?
There have been multiple attempts over the years to separate
physical and logical column positions. They've failed :-(.
You might trawl the mail list archives for awhile to understand the
problem better. Maybe a determined person could write a successful
patch, but don't underestimate the complexity and risk of introducing
new bugs.
regards, tom lane