Segmentation Fault

[no0p]

Hi -- Huge fan of this library. This may be a user error issue as I'm a little out of my element here.

I'm working on a quixotic addition to this lib that creates a function which automatically loads some basic schema info from the mysql. I setup a foreign server and credentials ok, and add a normal table which I can select against ok. Next...

create foreign table mysql_columns (table_name text, column_name text) server mysql_svr options (table 'information_schema.columns');

Then when I execute a select against mysql_columns a segfault occurs.

Here is the backtrace from gdb:

(gdb) backtrace
#0  0x00007fd7cb1567ab in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007fd7c4fffe83 in atof (__nptr=<optimized out>)
    at /usr/include/stdlib.h:281
#2  mysqlPlanForeignScan (foreigntableid=<optimized out>, 
    root=<optimized out>, baserel=0x7fd7ce3b17d8) at mysql_fdw.c:466
#3  0x00007fd7cd304f7a in create_foreignscan_path ()
#4  0x00007fd7cd2dae07 in ?? ()
#5  0x00007fd7cd2db215 in make_one_rel ()
#6  0x00007fd7cd2f1633 in query_planner ()
#7  0x00007fd7cd2f2f31 in ?? ()
#8  0x00007fd7cd2f4b41 in subquery_planner ()
#9  0x00007fd7cd2f4e07 in standard_planner ()
#10 0x00007fd7cd355a70 in pg_plan_query ()
#11 0x00007fd7cd355b74 in pg_plan_queries ()
#12 0x00007fd7cd35658e in PostgresMain ()
#13 0x00007fd7cd318791 in ?? ()
#14 0x00007fd7cd3194d1 in PostmasterMain ()
#15 0x00007fd7cd16cdb9 in main ()

I'm continuing to investigate but am a bit of a novice in such matters. Thanks!

update: A one line hack to get this working is on my fork but I'm reluctant to suggest its an actual fix since I don't understand the problem fully.

[dpage]

Hi

On Sun, Mar 24, 2013 at 4:03 PM, Robert Berry notifications@github.comwrote:

Hi -- Huge fan of this library. This may be a user error issue as I'm a
little out of my element here.

I'm working on a quixotic addition to this lib that creates a function
which automatically loads some basic schema info from the mysql. I setup a
foreign server and credentials ok, and add a normal table which I can
select against ok. Next...

create foreign table mysql_columns (table_name text, column_name text) server mysql_svr options (table 'information_schema.columns');

Then when I execute a select against mysql_columns a segfault occurs.

Here is the backtrace from gdb:

(gdb) backtrace
#0 0x00007fd7cb1567ab in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#1 0x00007fd7c4fffe83 in atof (__nptr=)
at /usr/include/stdlib.h:281
#2 mysqlPlanForeignScan (foreigntableid=,
root=, baserel=0x7fd7ce3b17d8) at mysql_fdw.c:466
#3 0x00007fd7cd304f7a in create_foreignscan_path ()
#4 0x00007fd7cd2dae07 in ?? ()
#5 0x00007fd7cd2db215 in make_one_rel ()
#6 0x00007fd7cd2f1633 in query_planner ()
#7 0x00007fd7cd2f2f31 in ?? ()
#8 0x00007fd7cd2f4b41 in subquery_planner ()
#9 0x00007fd7cd2f4e07 in standard_planner ()
#10 0x00007fd7cd355a70 in pg_plan_query ()
#11 0x00007fd7cd355b74 in pg_plan_queries ()
#12 0x00007fd7cd35658e in PostgresMain ()
#13 0x00007fd7cd318791 in ?? ()
#14 0x00007fd7cd3194d1 in PostmasterMain ()
#15 0x00007fd7cd16cdb9 in main ()

I'm continuing to investigate but am a bit of a novice in such matters.
Thanks!

What does the output of the EXPLAIN query look like if you run it manually?
I can imagine the fix you've used could well be correct, but I don't have a
copy of mysql to hand, and don't know it well enough to know what it's
likely to be returning.

Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

[dpage]

No response received after 9 months - closing.