Segfault of 19.17.7 (related to mismatched types in VIEW and underlying table)

[filimonov]

Stacktrace 1:
2020.04.02 09:27:09.209411 [ 109 ] {} <Fatal> BaseDaemon: ########################################
2020.04.02 09:27:09.209477 [ 109 ] {} <Fatal> BaseDaemon: (version 19.17.7.52 (official build)) (from thread 71) Received signal Segmentation fault (11).
2020.04.02 09:27:09.209514 [ 109 ] {} <Fatal> BaseDaemon: Address: NULL pointer. Access: read. Unknown si_code.
2020.04.02 09:27:09.209551 [ 109 ] {} <Fatal> BaseDaemon: Stack trace: 0x55d7593bd26b 0x55d75a241dbb 0x55d75a242241 0x55d75a1986a5 0x55d75a1993e8 0x55d75a134c3f 0x55d75a1355ed 0x55d75678330c 0x55d75c52bb80 0x7f305b2186db 0x7f305ab3588f
2020.04.02 09:27:09.209647 [ 109 ] {} <Fatal> BaseDaemon: 3. 0x55d7593bd26b DB::IAggregateFunctionHelper<DB::AggregateFunctionNullUnary<true> >::addBatch(unsigned long, char**, unsigned long, DB::IColumn const**, DB::Arena*) const /usr/bin/clickhouse
2020.04.02 09:27:09.209740 [ 109 ] {} <Fatal> BaseDaemon: 4. 0x55d75a241dbb void DB::Aggregator::executeImplBatch<DB::AggregationMethodSerialized<HashMapTable<StringRef, HashMapCellWithSavedHash<StringRef, char*, DefaultHash<StringRef, void>, HashTableNoState>, DefaultHash<StringRef, void>, HashTableGrower<8ul>, Allocator<true, true> > > >(DB::AggregationMethodSerialized<HashMapTable<StringRef, HashMapCellWithSavedHash<StringRef, char*, DefaultHash<StringRef, void>, HashTableNoState>, DefaultHash<StringRef, void>, HashTableGrower<8ul>, Allocator<true, true> > >&, DB::AggregationMethodSerialized<HashMapTable<StringRef, HashMapCellWithSavedHash<StringRef, char*, DefaultHash<StringRef, void>, HashTableNoState>, DefaultHash<StringRef, void>, HashTableGrower<8ul>, Allocator<true, true> > >::State&, DB::Arena*, unsigned long, DB::Aggregator::AggregateFunctionInstruction*) const /usr/bin/clickhouse
2020.04.02 09:27:09.209817 [ 109 ] {} <Fatal> BaseDaemon: 5. 0x55d75a242241 void DB::Aggregator::executeImpl<DB::AggregationMethodSerialized<HashMapTable<StringRef, HashMapCellWithSavedHash<StringRef, char*, DefaultHash<StringRef, void>, HashTableNoState>, DefaultHash<StringRef, void>, HashTableGrower<8ul>, Allocator<true, true> > > >(DB::AggregationMethodSerialized<HashMapTable<StringRef, HashMapCellWithSavedHash<StringRef, char*, DefaultHash<StringRef, void>, HashTableNoState>, DefaultHash<StringRef, void>, HashTableGrower<8ul>, Allocator<true, true> > >&, DB::Arena*, unsigned long, std::vector<DB::IColumn const*, std::allocator<DB::IColumn const*> >&, DB::Aggregator::AggregateFunctionInstruction*, bool, char*) const /usr/bin/clickhouse
2020.04.02 09:27:09.209875 [ 109 ] {} <Fatal> BaseDaemon: 6. 0x55d75a1986a5 DB::Aggregator::executeOnBlock(std::vector<COW<DB::IColumn>::immutable_ptr<DB::IColumn>, std::allocator<COW<DB::IColumn>::immutable_ptr<DB::IColumn> > >, unsigned long, DB::AggregatedDataVariants&, std::vector<DB::IColumn const*, std::allocator<DB::IColumn const*> >&, std::vector<std::vector<DB::IColumn const*, std::allocator<DB::IColumn const*> >, std::allocator<std::vector<DB::IColumn const*, std::allocator<DB::IColumn const*> > > >&, bool&) /usr/bin/clickhouse
2020.04.02 09:27:09.209932 [ 109 ] {} <Fatal> BaseDaemon: 7. 0x55d75a1993e8 DB::Aggregator::executeOnBlock(DB::Block const&, DB::AggregatedDataVariants&, std::vector<DB::IColumn const*, std::allocator<DB::IColumn const*> >&, std::vector<std::vector<DB::IColumn const*, std::allocator<DB::IColumn const*> >, std::allocator<std::vector<DB::IColumn const*, std::allocator<DB::IColumn const*> > > >&, bool&) /usr/bin/clickhouse
2020.04.02 09:27:09.209968 [ 109 ] {} <Fatal> BaseDaemon: 8. 0x55d75a134c3f DB::ParallelInputsProcessor<DB::ParallelAggregatingBlockInputStream::Handler>::thread(std::shared_ptr<DB::ThreadGroupStatus>, unsigned long) /usr/bin/clickhouse
2020.04.02 09:27:09.210027 [ 109 ] {} <Fatal> BaseDaemon: 9. 0x55d75a1355ed ThreadFromGlobalPool::ThreadFromGlobalPool<void (DB::ParallelInputsProcessor<DB::ParallelAggregatingBlockInputStream::Handler>::*)(std::shared_ptr<DB::ThreadGroupStatus>, unsigned long), DB::ParallelInputsProcessor<DB::ParallelAggregatingBlockInputStream::Handler>*, std::shared_ptr<DB::ThreadGroupStatus>, unsigned long&>(void (DB::ParallelInputsProcessor<DB::ParallelAggregatingBlockInputStream::Handler>::*&&)(std::shared_ptr<DB::ThreadGroupStatus>, unsigned long), DB::ParallelInputsProcessor<DB::ParallelAggregatingBlockInputStream::Handler>*&&, std::shared_ptr<DB::ThreadGroupStatus>&&, unsigned long&)::{lambda()#1}::operator()() const /usr/bin/clickhouse
2020.04.02 09:27:09.210066 [ 109 ] {} <Fatal> BaseDaemon: 10. 0x55d75678330c ThreadPoolImpl<std::thread>::worker(std::_List_iterator<std::thread>) /usr/bin/clickhouse
2020.04.02 09:27:09.210108 [ 109 ] {} <Fatal> BaseDaemon: 11. 0x55d75c52bb80 ? /usr/bin/clickhouse
2020.04.02 09:27:09.210145 [ 109 ] {} <Fatal> BaseDaemon: 12. 0x7f305b2186db start_thread /lib/x86_64-linux-gnu/libpthread-2.27.so
2020.04.02 09:27:09.210184 [ 109 ] {} <Fatal> BaseDaemon: 13. 0x7f305ab3588f clone /lib/x86_64-linux-gnu/libc-2.27.so

Query is quite complicated, it start appearing after one of VIEWs used in that query the type of column in underlying table was changed like that:

CREATE table x ( x FixedString(2) ) Engine=MergeTree() ORDER BY tuple();
CREATE VIEW y AS select x, dictGet('...', '...', tuple(toString(x))) x_dicted FROM x; -- the query which crashed use that view
CREATE table x_new ( x String ) Engine=MergeTree() ORDER BY tuple();
RENAME TABLE x TO x_old, x_new TO x;

i wasn't able to reproduce it on simple test case fast.

UPD: recreating of VIEW with proper type resolved the issue.