Re: odd behavior in materialized view

On Thu, Mar 7, 2013 at 8:21 AM, Kevin Grittner <kgrittn(at)ymail(dot)com> wrote:
> Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
>> On Tue, Mar 5, 2013 at 7:36 AM, Kevin Grittner <kgrittn(at)ymail(dot)com> wrote:
>>> Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
>>>
>>>> When I accessed the materialized view in the standby server,
>>>
>>>> I got the following ERROR message. Looks odd to me. Is this a bug?
>>>>
>>>> ERROR: materialized view "hogeview" has not been populated
>>>> HINT: Use the REFRESH MATERIALIZED VIEW command.
>>>>
>>>> The procedure to reproduce this error message is:
>>>>
>>>> In the master server:
>>>> CREATE TABLE hoge (i int);
>>>> INSERT INTO hoge VALUES (generate_series(1,100));
>>>> CREATE MATERIALIZED VIEW hogeview AS SELECT * FROM hoge;
>>>> DELETE FROM hoge;
>>>> REFRESH MATERIALIZED VIEW hogeview;
>>>> SELECT count(*) FROM hogeview;
>>>>
>>>> In the standby server
>>>> SELECT count(*) FROM hogeview;
>>>>
>>>> SELECT count(*) goes well in the master, and expectedly returns 0.
>>>> OTOH, in the standby, it emits the error message.
>>>
>>> Will investigate.
>>
>> Thanks!
>>
>> And I found another problem. When I ran the following SQLs in the master,
>> PANIC error occurred in the standby.
>>
>> CREATE TABLE hoge (i int);
>> INSERT INTO hoge VALUES (generate_series(1,100));
>> CREATE MATERIALIZED VIEW hogeview AS SELECT * FROM hoge;
>> VACUUM ANALYZE;
>>
>> The PANIC error messages that I got in the standby are
>>
>> WARNING: page 0 of relation base/12297/16387 is uninitialized
>> CONTEXT: xlog redo visible: rel 1663/12297/16387; blk 0
>> PANIC: WAL contains references to invalid pages
>> CONTEXT: xlog redo visible: rel 1663/12297/16387; blk 0
>>
>> base/12297/16387 is the file of the materialized view 'hogeview'.
>
> I was able to replicate both bugs, and they both appear to be fixed
> by the attached, which I have just pushed.

Thanks! I confirmed that the problem that I reported has disappeared in HEAD.

Unfortunately I found another odd behavior. When I accessed the MV
after VACUUM ANALYZE, I got the following error.

ERROR: materialized view "hogeview" has not been populated
HINT: Use the REFRESH MATERIALIZED VIEW command.
STATEMENT: select * from hogeview where i < 10;

The test case to reproduce that is:

create table hoge (i int);
insert into hoge values (generate_series(1,100000));
create materialized view hogeview as select * from hoge where i % 2 = 0;
create index hogeviewidx on hogeview (i);
delete from hoge;
refresh materialized view hogeview;
select * from hogeview where i < 10;
vacuum analyze;
select * from hogeview where i < 10;

The last SELECT command caused the above error.

Regards,

--
Fujii Masao