database/mariadb-columnstore-engine
1
0
Fork 0
mirror of https://github.com/mariadb-corporation/mariadb-columnstore-engine.git synced 2025-07-29 08:21:15 +03:00
Code Activity

MCOL-5153 This patch replaces MDB collation aware hash function with the (#2488)

Browse Source 
exact functionality that does not use MDB hash function.
This patch also takes a bit from Robin Hood hash map implementation forgotten
that reduces hash function collision rate.
This commit is contained in:
Roman Nozdrin
2022-08-07 02:36:03 +03:00
committed by GitHub
parent af9caf8d6e
commit dd96e686c0
4 changed files with 59 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

41
utils/rowgroup/rowstorage.cpp
View File

@ -166,10 +166,24 @@ uint64_t hashRow(const rowgroup::Row& r, std::size_t lastCol)
case execplan::CalpontSystemCatalog::VARCHAR:
case execplan::CalpontSystemCatalog::BLOB:
case execplan::CalpontSystemCatalog::TEXT:
h.add(r.getCharset(i), r.getConstString(i));
strHashUsed = true;
{
auto strColValue = r.getConstString(i);
if (strColValue.length() > MaxConstStrSize)
{
h.add(r.getCharset(i), strColValue);
strHashUsed = true;
}
else
{
auto cs = r.getCharset(i);
uchar buf[MaxConstStrBufSize];
uint nActualWeights = cs->strnxfrm(buf, MaxConstStrBufSize, MaxConstStrBufSize,
reinterpret_cast<const uchar*>(strColValue.str()), strColValue.length(),
datatypes::Charset::getDefaultFlags());
ret = hashData(buf, nActualWeights, ret);
}
break;
}
default: ret = hashData(r.getData() + r.getOffset(i), r.getColumnWidth(i), ret); break;
}
}
@ -1820,15 +1834,26 @@ void RowAggStorage::increaseSize()
if (fCurData->fSize * maxMaskMultiplierWoRehashing < calcMaxSize(fCurData->fMask + 1))
{
// something strange happens...
throw logging::IDBExcept(logging::IDBErrorInfo::instance()->errorMsg(logging::ERR_DISKAGG_ERROR),
logging::ERR_DISKAGG_ERROR);
throw logging::IDBExcept(logging::IDBErrorInfo::instance()->errorMsg(logging::ERR_DISKAGG_OVERFLOW2),
logging::ERR_DISKAGG_OVERFLOW2);
}
auto freeMem = fMM->getFree();
if (fEnabledDiskAggregation ||
freeMem > (fMM->getUsed() + fCurData->fHashes->memUsage() + fStorage->getAproxRGSize()) * 2)
{
rehashPowerOfTwo((fCurData->fMask + 1) * 2);
if (fCurData->fSize * 2 < maxSize)
{
// we have to resize, even though there would still be plenty of space left!
// Try to rehash instead. Delete freed memory so we don't steadyily increase mem in case
// we have to rehash a few times
nextHashMultiplier();
rehashPowerOfTwo(fCurData->fMask + 1);
}
else
{
rehashPowerOfTwo((fCurData->fMask + 1) * 2);
}
}
else if (fGeneration < MAX_INMEMORY_GENS - 1)
{
@ -1888,8 +1913,8 @@ void RowAggStorage::insertSwap(size_t oldIdx, RowPosHashStorage* oldHashes)
{
if (fCurData->fMaxSize == 0 && !tryIncreaseInfo())
{
throw logging::IDBExcept(logging::IDBErrorInfo::instance()->errorMsg(logging::ERR_DISKAGG_ERROR),
logging::ERR_DISKAGG_ERROR);
throw logging::IDBExcept(logging::IDBErrorInfo::instance()->errorMsg(logging::ERR_DISKAGG_OVERFLOW1),
logging::ERR_DISKAGG_OVERFLOW1);
}
size_t idx{};