Allow `ATTACH TABLE [db.]name` if the table was previously detached,
an the table structure can be read from disk. This makes reattaching
tables less cumbersome:
```
CREATE TABLE test.t (x UInt8) ENGINE = Null;
DETACH TABLE test.t;
ATTACH TABLE test.t;
```
This allows creation of materialized views without inner tables,
using an existing table for materialized rows instead.
This is useful for cases when you want to detach the materializing
view, but keep the already materialized data readable, especially
when the inner table is replicated.
fix hash index in CatBoostModel [#CLICKHOUSE-3305]
fix hash index in CatBoostModel [#CLICKHOUSE-3305]
fix hash index in CatBoostModel [#CLICKHOUSE-3305]
fix string features in CatBoostModel [#CLICKHOUSE-3305]
* do not write out partition and minmax index files for old MergeTreeData format
* download the part from another replica if there are missing or extra files
The tryGet() operation creates a 1MB buffer on stack. This may or
may not work depending on the default stack size for threads,
whether the stack protector is enabled or not, recursion depth,
and the actual value size.
This is probably going to slow down some ZK operations, but I don't
see how else this could work reliably with the existing API.
In the current version of Poco, unsigned long no longer aliases to
UInt64 with LP64. The size_t aliases to unsigned long with clang,
so all the uses of size_t instead of UInt64 when interacting with
Poco interfaces are gone. I replaced uses with UInt64 where it makes
sense, and added an overloaded function for readVarUInt() to support size_t.
The built-in clang doesn’t support value() for
`std::experimental::optional`. It however supports
dereference operator, which is basically the
same thing:
```
/clickhouse/dbms/src/DataStreams/NullableAdapterBlockInputStream.cpp:83:67: error: call to unavailable member function 'value':
res.insert({elem.column, elem.type, rename[i].value()});
~~~~~~~~~~^~~~~
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/experimental/optional:547:17: note: candidate function has been explicitly made unavailable
value_type& value()
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/experimental/optional:539:33: note: candidate function has been explicitly made unavailable
constexpr value_type const& value() const
```
