Simon Riggs <simon@2ndQuadrant.com> writes:
> There are various applications where we want to completely replace the
> contents of a table with new/re-calculated data.
> It seems fairly obvious to be able to do this like...
> 1. Prepare new data into "new_table" and build indexes
> 2. Swap old for new
> BEGIN;
> DROP TABLE "old_table";
> ALTER TABLE "new_table" RENAME to "old_table";
> COMMIT;
Why not
BEGIN;
TRUNCATE TABLE;
... load new data ...
COMMIT;
> What I propose is to write a function/command to allow this to be
> explicitly achievable by the server.
> ALTER TABLE "old_table"
> REPLACE WITH "new_table";
I don't think the cost/benefit ratio of this is anywhere near as good
as you seem to think (ie, you're both underestimating the work involved
and overstating the benefit). I'm also noticing a lack of specification
as to trigger behavior, foreign keys, etc. The apparent intention to
disregard FKs entirely is particularly distressing,
regards, tom lane