PostgreSQL reset tables to original state

Question

We have a large PostgreSQL dump with hundreds of tables that I can successfully import with pg_restore. We are developing a software that inserts into a lot of these tables (~100) and for every run we need to return these tables to their original state (that means to the content that was in the dump). Restoring the original dump again takes a lot of time and we just can't wait for half an hour before every debugging session. So I need a relatively fast way to revert these tables to the state they are in after restoring from the dump.

I've tried using pg_restore with -L switch and selecting these tables but I get either a duplicate key error when using both --data-only and --clean or a "cannot drop table X because other objects depend on it" error when using only --clean. Issuing a SET CONSTRAINTS ALL DEFERRED command before pg_restore did not work either. Maybe I have the rows in the table list all wrong, right now it's

491; 1259 39623998 TABLE public some_table some_user
8021; 0 0 COMMENT public TABLE some_table some_user
8022; 0 0 ACL public some_table some_user

for every table and then

6700; 0 39624062 TABLE DATA public some_table postgres
8419; 0 0 SEQUENCE SET public some_table_pk_id_seq some_user

for every table.

We only insert data and don't update existing rows so deleting all rows above an index and resetting the sequences might work, but I really don't want to have to manually create these commands for all the hundred tables and I'm not even sure it would work even if I set cascade to delete other objects depending on the given row.

Does anyone have any better idea how to handle this?

Answer 1

So you are looking for something like a snapshot in order to be able to revert quickly to a certain state.

I am not aware of a possiblity in PostgreSql to rollback to a certain timestamp.

While searching for a solution, I've found two ideas here

• Use create database with the template option
• Virtualize your PostgreSql installation using VMWare or VirtualBox, and use the snapshot feature of the virtual machines.

Again, both ideas are copied from the above source (I have search for "postgresql db snapshots").