langgraph-checkpoint-postgres indicates an error

[yuruicai]

I have a problem with checkpoint implementation using postgres. What is the best way to solve it

select
thread_id,
checkpoint,
checkpoint_ns,
checkpoint_id,
parent_checkpoint_id,
metadata,
(
select array_agg(array[bl.channel::bytea, bl.type::bytea, bl.blob])
from jsonb_each_text(checkpoint -> 'channel_versions')
inner join checkpoint_blobs bl
on bl.thread_id = checkpoints.thread_id
and bl.checkpoint_ns = checkpoints.checkpoint_ns
and bl.channel = jsonb_each_text.key
and bl.version = jsonb_each_text.value
) as channel_values,
(
select
array_agg(array[cw.task_id::text::bytea, cw.channel::bytea, cw.type::bytea, cw.blob])
from checkpoint_writes cw
where cw.thread_id = checkpoints.thread_id
and cw.checkpoint_ns = checkpoints.checkpoint_ns
and cw.checkpoint_id = checkpoints.checkpoint_id
) as pending_writes
from checkpoints

--result--

ERROR: could not find array type for data type bytea[]
, Time: 0.007000s

-- Hope to be answered to solve this problem

[vbarda]

@yuruicai how are you getting this error? can you paste the code you're running?

[yuruicai]

I used langgraph langgraph-checkpoint-Postgres to achieve checkpoints based on postgres.
I guess I'm using the aliyun service that doesn't support this kind of syntax to cause this problem.

ERROR: could not find array type for data type bytea[]

--
The db version I used was

PostgreSQL 9.4.24 (Greenplum Database 6.3.0 build dev) on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 9.2.1 20200522 (Alibaba 9.2.1-3 2.17), 64-bit compiled on Aug 22 2023 10:31:37

[vbarda]

this seems to be a very old version of postgres -- i would recommend using 15 or 16

[yuruicai]

Yes, you are right

-- Thank you for your answer