On 7/29/16, Keith Fiske <keith@xxxxxxxxxx> wrote: > On Fri, Jul 29, 2016 at 12:53 AM, Vitaly Burovoy <vitaly.burovoy@xxxxxxxxx> > wrote: > >> On 7/28/16, Keith Fiske <keith@xxxxxxxxxx> wrote: >> > Working on trying to get a C version of the maintenance function for my >> > pg_partman extension working so I can hopefully make it more flexible >> > and >> > efficient. >> > >> https://gist.github.com/keithf4/81c32bf8b689c74b20c10ad8c91d45a3#file-pg_partman_bgw-c-L532 >> > >> > There's what I've got working so far and links directly to the area >> > where >> > I'm having a problem. I found the DatumGetTimeTzADTP() function and the >> > TimeTzADT data type looking through the source and that seems to be exactly >> > what I'm looking for. However, when I get to the point of trying to simply >> > use the time value in that variable (line 544), Postgres segfaults. So far >> > I've just been trying to print the value out to the log to ensure I'm >> > pulling it out correctly. The "time" value of the struct appears to be >> > an >> > int64, so I thought %ld would be the correct, but even using %d or %s >> > fails. >> > >> > Thanks! >> > >> > -- >> > Keith Fiske >> > Database Administrator >> > OmniTI Computer Consulting, Inc. >> > http://www.keithf4.com >> > >> >> I think it is not about timestamp(tz), but about usage of SPI. >> Since DatumGetTimeTzADTP is just a macros implements type conversion >> (declared at src/include/utils/date.h:60 (or 75)) you get segfault not >> in it but when the code tries to get value by dereference pointer >> (last_partition_timestamp->time). >> >> Please, answer questions: >> 1. How many rows SPI_execute returns (value of "ret" variable)? >> 2. Is last_partition_timestamp != NULL? Where it points to? >> 3. Try to check SPI_result just after SPI_getbinval. Has it error code? > > > It returns a single row. Here's an example of the results of the two > queries that are run that lead to providing the timestamp value > > keith=# select partition_tablename from > partman.show_partitions('partman_test.time_taptest_table', 'DESC') limit > 1; partition_tablename > -------------------------------- > time_taptest_table_p2016_08_02 > (1 row) > > keith=# select child_start_time from > partman.show_partition_info('partman_test.time_taptest_table_p2016_08_02', > '1 day', 'partman_test.time_taptest_table'); > child_start_time > ------------------------ > 2016-08-02 00:00:00-04 > (1 row) > > So there is valid data. As you're pointing out, this may just be a > misunderstanding of how to actually use the Datum retrieval function and C > in general. Appreciate the assistance. > > Keith > Please, add next lines (or debug this values via gdb) and post a result: ret = SPI_execute(buf.data, true, 1); ereport(NOTICE, (errmsg("query=%s", buf.data))); ereport(NOTICE, (errmsg("ret=%i -- rows=%ju", ret, SPI_processed))); last_partition_timestamp = DatumGetTimeTzADTP(SPI_getbinval(SPI_tuptable->vals[0], SPI_tuptable->tupdesc, 1, &isnull)); ereport(NOTICE, (errmsg("SPI_result=%d -- ptr=%p", SPI_result, (void*)last_partition_timestamp ))); /* elog(LOG, "Just seeing if it's time partitioned: %ld", last_partition_timestamp->time); --prevent segfaulting */ -- Best regards, Vitaly Burovoy -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
