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://github.com/keithf4/pg_partman/blob/master/sql/functions/run_maintenance.sql > > Up until this point I've just been using SPI and the Datum conversion > functions (DatumGetCString, DatumGetInt32) to get string and numeric data > out of tables and things have been working fine. I'm at the first point in > that function where I'll need to start dealing with timestamp data. > > 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. > > You can see in my original plpgsql function how I eventually intend to use > the timestamp values. Here's a link directly to the equivalent section > > https://github.com/keithf4/pg_partman/blob/master/sql/functions/run_maintenance.sql#L139 > > So, not sure if I'm even going about this the right manner for the way I > intend to use the timestamp values. Still fairly new to C and getting use > to postgres internals. Any help, or even an example of using timstamp data > pulled from a table in C with SPI, would be great. > > 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? -- 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
