Re: A question about sequences and backup/restore cycles

On 10/22/19 1:35 PM, stan wrote:
> On Tue, Oct 22, 2019 at 12:48:41PM -0700, Adrian Klaver wrote:
>> On 10/22/19 10:48 AM, stan wrote:
>> Please reply to list also:
>> Ccing list.
>>
>>
>>>
>>> Sorry if my description was not clear.
>>>
>>> No, we  do not mix test, and production data. Let me try to clarify the
>>> question. Looking at a pg_dump, I see the following:
>>>
>>>
>>> CREATE SEQUENCE public.customer_key_serial
>>>       START WITH 1
>>>     INCREMENT BY 1
>>>     NO MINVALUE
>>>     NO MAXVALUE
>>>     CACHE 1;
>>>
>>>
>>> Yet, in the same pg_dump file I have:
>>>
>>>
>>>
>>>
>>> COPY public.customer (customer_key, cust_no, name, c_type, location,
>>> bill_address_1, bill_address_2, bill_city, bill_state, bill_zip,
>>> bill_country, bill_attention, bill_addressee, ship_address_1,
>>> ship_address_2, ship_addressee, ship_attention, ship_city, ship_state,
>>> ship_zip, office_phone_area_code, office_phone_exchange,
>>> office_phone_number, office_phone_extension, cell_phone_area_code,
>>> cell_phone_exchange, cell_phone_number, ship_phone_area_code,
>>> ship_phone_exchange, ship_phone_number, ship_phone_extension,
>>> fax_phone_area_code, fax_phone_exchange, fax_phone_number, status, modtime)
>>> FROM stdin;
>>> 1       12      Made Up Inc.    INDUSTRIAL_CONVEYOR     \N      101 Nowhere
>>> Ave.        \N      LaGrange        GA      00000   \N      \N      \N
>>> \N      \N      \N      \N      \N      \N      00000   \N      \N      \N
>>>      \N      \N      \N      \N      \N      \N      \N      \N      \N
>>>      \N      \N      ACTIVE  2019-09-30 23:55:04.594203+00
>>>      2       5       Jimmys Favorite Customer.       PLASTICS        \N
>>>      56 Somewhere St.        \N      No Such City    SC      00000   \N
>>>      \N      \N      \N      \N      \N      \N      \N      \N      00000
>>>      \N      \N      \N      \N      \N      \N      \N      \N      \N
>>>      \N      \N      \N      \N      \N      ACTIVE  2019-09-30
>>>      23:55:04.636827+00
>>>
>>> So it appears to me the customer table is going to get (correctly) populated
>>> with the originally generated keys, yet the sequence will want to return a 1
>>> the next time it is called, when a new customer gets inserted.
>>>
>>> Am I missing something here?
>>>
>>
>> Yes something like this, in dump file, for non-serial sequence:
>>
>> CREATE SEQUENCE public.plant1_p_item_no_seq
>>      START WITH 1
>>      INCREMENT BY 1
>>      NO MINVALUE
>>      NO MAXVALUE
>>      CACHE 1;
>>
>> SELECT pg_catalog.setval('public.plant1_p_item_no_seq', 5509, true);
>>
>> or for serial sequence:
>>
>> CREATE SEQUENCE public.avail_headers_line_id_seq
>>      AS integer
>>      START WITH 1
>>      INCREMENT BY 1
>>      NO MINVALUE
>>      NO MAXVALUE
>>      CACHE 1;
>>
>> ALTER TABLE ONLY public.avail_headers ALTER COLUMN line_id SET DEFAULT
>> nextval('public.avail_headers_line_id_seq'::regclass);
>>
>>
>> SELECT pg_catalog.setval('public.avail_headers_line_id_seq', 53, true);
>>
>> If you want to see how things are run on a higher level do something like:
>>
>> pg_dump -Fc -d some_db -f db.out
>>
>> pg_restore -l db_out > db_toc.txt
>>
>> -l on pg_restore creates a TOC(table of contents) showing the ordering of
>> the schema recreation.
>>
>
> Oh, excellent. !!
>
> Thanks for the patience to teach me about this.
>
> Does make me wonder what the vendor did to create our issue on their
> database.
>

I thought it was your database you where concerned about?

In any case tracking down the issue would require more information then
has been provided. Like I said previously I would start with automated
scripts that did not get the memo about the database changing under them.


--
Adrian Klaver
adrian.klaver@aklaver.com