Leonid Fedorov 86c1c5d537 fix(rgdata)!: Fix assertion failure leading to disk-based aggregation failure ...

The new added invariant checking that RGData knows the number of columns and fixed size columns was failing for disk-based aggregation workloads, leading them to provide a wrong result. (The assertion failure happened in RGData::getRow(uint32_t num, Row* row) which is called in the finalization of sub-aggregation results, necessary for merging part results. As the merging failed, duplicate results were output for disk-based aggregation queries.
The assertion failure was caused by RGData::deserialize(ByteStream& bs,
uint32_t defAmount) not setting rowSize and colCount if necessary (e.g.
when the deserialization happens into a new, default RGData, which
doesn't know anything about its structure yet. This is the case when the
default constructor for RGData() is used, which sets rowSize and
columnCount to 0 each.
There are three code parts that make use of the default RGData() ctor.
The fix is for the use in RowGroupStorage::loadRG(uint64_t rgid,
std::unique_ptr<RGData>& rgdata, bool unlinkDump = false), where the
default RGData object is used to directly deserialize a ByteStream into
it. The deserialize method now checks if both rowSize and columnCount
are 0 and if yes sets the read values from the ByteStream for both.
We should probably check the other two code parts making use of the
default RGData ctor, too. This happens in joinpartition.cpp and
tuplejoiner.cpp.

---------

Co-authored-by: Theresa Hradilak <34538290+phoeinx@users.noreply.github.com>

2023-09-30 00:02:31 +03:00

45 KiB

Raw Permalink Blame History

View Raw