Uninitialized variable in parquetAcquireSampleRowsFunc

[jk-intel]

Hi,
The variable fdw_private in the following code is uninitialized:

parquetAcquireSampleRowsFunc(Relation relation, int /* elevel */,
HeapTuple *rows, int targrows,
double *totalrows,
double *totaldeadrows)
{
...
ParquetFdwPlanState fdw_private;

Since ParquetFdwPlanState has trivial default constructor, the members of the struct have garbage values.
The following call to get_table_options() doesn't initialize all members either. E.g. the pointer attrs_sorted may not get initialized.

I suggest to memset() the fdw_private to zero immediately after the declaration:
ParquetFdwPlanState fdw_private;
memset(&fdw_private, 0, sizeof(ParquetFdwPlanState));

(In general, there are uninitialized-at-declaration pointers scattered throughout parquet_impl.cpp. Coding style is of course subjective :), but perhaps it's better to always initialize them.)

[za-arthur]

Thanks @jk-intel for another report. I agree it makes sense to zero out the struct before usage. I checked the code and it seems only parquetAcquireSampleRowsFunc() and parquetGetForeignRelSize() initialize that struct, and latter allocate it using palloc0, therefore there is no need to run memset additionally:

parquet_fdw/src/parquet_impl.cpp

Line 1056 in caf7471

fdw_private = (ParquetFdwPlanState *) palloc0(sizeof(ParquetFdwPlanState));

I created a PR #85 with the fix.

[za-arthur]

Closing since the PR was merged.