Question: Why Rollback do not work for Postgres?
You are using the transaction bit incorrectly I would say. Here's how I would do it:

```python

for item in insert_items:
    with db.atomic() as txn:
        try:
            model.create(**item)
        except IntegrityError:
            txn.rollback()
        else:
            txn.commit()
``` Still getting `current transaction is aborted, commands ignored until end of transaction block` using described method. I'm sure you have some bug in your code. This works just fine:

```python
db = PostgresqlDatabase('peewee_test')

class Reg(Model):
    key = CharField(unique=True)
    class Meta:
        database = db

db.create_tables([Reg])
for k in 'abcadaec':
    with db.atomic() as txn:
        try:
            Reg.create(key=k)
        except IntegrityError:
            txn.rollback()
        else:
            txn.commit()

assert [r.key for r in Reg.select().order_by(Reg.key)] == list('abcde')
db.drop_tables([Reg])

``` Hmm, it works for soft inserts like `model.get_or_create()`, but causes block for strict `create` operation.

Don't know if it good by design, but it helps me and all working like magic now. Will check the sources for reference.

Thank you for your help! :) 
Hi!

Explicit rollback do not work. Moreover, it block all the transactions until the program end.

Peewee Versions is: 3.14.4

Code:
```python
from playhouse.pool import PooledPostgresqlExtDatabase
from playhouse.postgres_ext import (
    Model,
    CharField,
)

def get_db():
     return PooledPostgresqlExtDatabase(
        DB_NAME,
        user=DB_USER,
        password=DB_PASS,
        host=DB_HOST,
        port=DB_PORT,
        max_connections=32,
        autocommit=False,
        autorollback=False,
        stale_timeout=300,
    )

class ItemsModel(Model):
    name = CharField()


model = ItemsModel()

insert_items = []

for item in insert_items:
    db = get_db()
    with db.transaction():
        try:
            model.create(**item)
            db.commit()
        except Exception as e:
            db.rollback()
```

Any help is highly appreciated! 

Thank you!