Invalid default value of Decimal column under NOT strict sql mode may make TiFlash panic

[JinheLin]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

set sql_mode='ansi';

create table t (a int);

alter table t set tiflash replica 1;

-- use an empty string as the default value for decimal column
alter table t add column d decimal(34, 2) default '';
alter table t add column d2 decimal(34, 2) default 'abcd';
show create table t\G
***************************[ 1. row ]***************************
Table        | t
Create Table | CREATE TABLE `t` (
  `a` int(11) DEFAULT NULL,
  `d` decimal(34,2) DEFAULT '',
  `d2` decimal(34,2) DEFAULT 'abcd'
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin

insert into t(a) values (1),(2),(3),(4);

2. What did you expect to see? (Required)

TiFlash run normally.

set tidb_isolation_read_engines='tiflash';
select * from t;
+---+------+------+
| a | d    | d2   |
+---+------+------+
| 1 | 0.00 | 0.00 |
| 2 | 0.00 | 0.00 |
| 3 | 0.00 | 0.00 |
| 4 | 0.00 | 0.00 |
+---+------+------+

3. What did you see instead (Required)

TiFlash crashes repeatly.

[2024/02/27 12:12:14.666 +08:00] [ERROR] [Exception.cpp:89] ["Code: 32, e.displayText() = DB::Exception: Attempt to read after eof: physical_table_id=-1: (while preHandleSnapshot region_id=17143818, index=7, term=6), e.what() = DB::Exception, Stack trace:


       0x17385aa\tDB::throwReadAfterEOF() [tiflash+24348074]
                \tdbms/src/IO/VarInt.h:167
       0x6151a77\tvoid DB::readDecimalText<__int128>(DB::Decimal<__int128>&, DB::ReadBuffer&, unsigned int, unsigned int) [tiflash+102046327]
                \tdbms/src/IO/ReadHelpers.h:272
       0x6b37570\tTiDB::ColumnInfo::getDecimalValue(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) const [tiflash+112424304]
                \tdbms/src/Storages/Transaction/TiDB.cpp:230
       0x6b3606d\tTiDB::ColumnInfo::defaultValueToField() const [tiflash+112418925]
                \tdbms/src/Storages/Transaction/TiDB.cpp:195
       0x6c07f4b\tDB::setAlterCommandColumn(Poco::Logger*, DB::AlterCommand&, TiDB::ColumnInfo const&) [tiflash+113278795]
                \tdbms/src/TiDB/Schema/SchemaBuilder.cpp:87
       0x6be7155\tDB::detectSchemaChanges(Poco::Logger*, TiDB::TableInfo const&, TiDB::TableInfo const&) [tiflash+113144149]
                \tdbms/src/TiDB/Schema/SchemaBuilder.cpp:307
       0x6be3781\tDB::SchemaBuilder<DB::SchemaGetter, DB::SchemaNameMapper>::applyAlterPhysicalTable(std::__1::shared_ptr<TiDB::DBInfo> const&, std::__1::shared_ptr<TiDB::TableInfo> const&, std::__1::shared_ptr<DB::IManageableStorage> const&) [tiflash+113129345]
                \tdbms/src/TiDB/Schema/SchemaBuilder.cpp:335
       0x6bdeb03\tDB::SchemaBuilder<DB::SchemaGetter, DB::SchemaNameMapper>::applyAlterLogicalTable(std::__1::shared_ptr<TiDB::DBInfo> const&, std::__1::shared_ptr<TiDB::TableInfo> const&, std::__1::shared_ptr<DB::IManageableStorage> const&) [tiflash+113109763]
                \tdbms/src/TiDB/Schema/SchemaBuilder.cpp:425
       0x6bdb135\tDB::SchemaBuilder<DB::SchemaGetter, DB::SchemaNameMapper>::syncAllSchema() [tiflash+113094965]
                \tdbms/src/TiDB/Schema/SchemaBuilder.cpp:1357
       0x6b22386\tDB::TiDBSchemaSyncer<false, false>::syncSchemas(DB::Context&) [tiflash+112337798]
                \tdbms/src/TiDB/Schema/TiDBSchemaSyncer.h:131
       0x6aba030\tDB::AtomicGetStorageSchema(std::__1::shared_ptr<DB::Region> const&, DB::TMTContext&) [tiflash+111910960]
                \tdbms/src/Storages/Transaction/PartitionStreams.cpp:530
       0x6a67640\tDB::KVStore::preHandleSSTsToDTFiles(std::__1::shared_ptr<DB::Region>, DB::SSTViewVec, unsigned long, unsigned long, DB::DM::FileConvertJobType, DB::TMTContext&) [tiflash+111572544]
                \tdbms/src/Storages/Transaction/ApplySnapshot.cpp:316
       0x6a67214\tDB::KVStore::preHandleSnapshotToFiles(std::__1::shared_ptr<DB::Region>, DB::SSTViewVec, unsigned long, unsigned long, DB::TMTContext&) [tiflash+111571476]
                \tdbms/src/Storages/Transaction/ApplySnapshot.cpp:275
       0x6ac2516\tPreHandleSnapshot [tiflash+111944982]
                \tdbms/src/Storages/Transaction/ProxyFFI.cpp:388
  0x7f70f66e9228\tengine_store_ffi::_$LT$impl$u20$engine_store_ffi..interfaces..root..DB..EngineStoreServerHelper$GT$::pre_handle_snapshot::hec57f9b0ef29a0bb [libtiflash_proxy.so+17646120]
  0x7f70f66e0d09\tengine_store_ffi::observer::pre_handle_snapshot_impl::h0b40090f59175b24 [libtiflash_proxy.so+17612041]
  0x7f70f66d3b86\tyatp::task::future::RawTask$LT$F$GT$::poll::hd3296fb5cae316b9 [libtiflash_proxy.so+17558406]
  0x7f70f855ff13\t_$LT$yatp..task..future..Runner$u20$as$u20$yatp..pool..runner..Runner$GT$::handle::h0056e31c4da70e35 [libtiflash_proxy.so+49590035]
  0x7f70f85527fc\tstd::sys_common::backtrace::__rust_begin_short_backtrace::h747afb2668c16dcb [libtiflash_proxy.so+49534972]
  0x7f70f855331c\tcore::ops::function::FnOnce::call_once$u7b$$u7b$vtable.shim$u7d$$u7d$::h83ec6721ad8db87f [libtiflash_proxy.so+49537820]
  0x7f70f7cc06a5\tstd::sys::unix::thread::Thread::new::thread_start::hd2791a9cabec1fda [libtiflash_proxy.so+40548005]
                \t/rustc/96ddd32c4bfb1d78f0cd03eb068b1710a8cebeef/library/std/src/sys/unix/thread.rs:108
  0x7f70f5400ea5\tstart_thread [libpthread.so.0+32421]
  0x7f70f4805b0d\tclone [libc.so.6+1043213]"] [source="DB::RawCppPtr DB::PreHandleSnapshot(DB::EngineStoreServerWrap *, DB::BaseBuffView, uint64_t, DB::SSTViewVec, uint64_t, uint64_t)"] [thread_id=318]

4. What is your TiFlash version? (Required)

v6.5.5

[seiya-annie]

/found customer

[JaySon-Huang]

Note: does not affect 8.1. Have been fixed before v8.1.0