Building Postgresql C function with Multidimensional Array as input -

i extending postgresql functions using c spi. function needs able take in postgres n-dim array , data out of it. able data 1d array segfault when trying access n-dim array.

my first try access element simply

pg_function_info_v1(sum_elements); datum matmul(pg_function_args) {      arraytype *anyarray = pg_getarg_arraytype_p(0);     int32 **a = (int32 **)  arr_data_ptr(anyarray);        pg_return_int64(a[1][1]); } 

i tried if flattened matrix 1d array values came out garbage.

thanks help!

you can try using deconstruct_array (..) function extract values. function give datum type pointer.

example of book:

deconstruct_array(input_array, //one-dimensional array                   int4oid, //of integers                   4,//size of integer in bytes                   true,//int4 pass-by value                   'i',//alignment type 'i'                   &datums, &nulls, &count); // result here        

"the datums pointer set point array filled actual elements."

you can access values using:

datumgetint32(datums[i]);