// from clause -
// pair each from item with cross join, their join conditions will be handled
// with where clause processing.
//
LogicNode transformFromClause()
{
LogicNode transformOneFrom(TableRef tab)
{
LogicNode from;
switch (tab)
{
case BaseTableRef bref:
if (bref.Table().source_ == TableDef.TableSource.Table)
{
from = new LogicScanTable(bref);
}
else
{
from = new LogicScanStream(bref);
}
if (bref.tableSample_ != null)
{
from = new LogicSampleScan(from, bref.tableSample_);
}
break;
case ExternalTableRef eref:
from = new LogicScanFile(eref);
break;
case CTEQueryRef cref:
if (this is CteSelectStmt css && css.CteId() == cref.cte_.cteId_)
{
cref.query_.cteInfo_ = cteInfo_;
var ctePlan = cref.query_.CreatePlan();
string alias = null;
NamedQuery key;
alias = cref.alias_;
key = new NamedQuery(cref.query_, alias, NamedQuery.QueryType.FROM);
from = new LogicFromQuery(cref, ctePlan);
subQueries_.Add(key);
if (!fromQueries_.ContainsKey(key))
{
fromQueries_.Add(key, from as LogicFromQuery);
}
}
else
{
from = new LogicCteConsumer(cteInfo_.GetCteInfoEntryByCteId(cref.cte_.cteId_), cref);
}
break;
// from clause -
// pair each from item with cross join, their join conditions will be handled
// with where clause processing.
//
LogicNode transformFromClause()
{
LogicNode transformOneFrom(TableRef tab)
{
LogicNode from;
switch (tab)
{
case BaseTableRef bref:
if (bref.Table().source_ == TableDef.TableSource.Table)
{
from = new LogicScanTable(bref);
}
else
{
from = new LogicScanStream(bref);
}
if (bref.tableSample_ != null)
{
from = new LogicSampleScan(from, bref.tableSample_);
}
break;
case ExternalTableRef eref:
from = new LogicScanFile(eref);
break;
case QueryRef qref:
var plan = qref.query_.CreatePlan();
if (qref is FromQueryRef && queryOpt_.optimize_.remove_from_)
{
from = plan;
}
else
{
string alias = null;
if (qref is CTEQueryRef cq)
{
alias = cq.alias_;
}
else if (qref is FromQueryRef fq)
{
alias = fq.alias_;
}
var key = new NamedQuery(qref.query_, alias);
from = new LogicFromQuery(qref, plan);
subQueries_.Add(key);
// if from CTE, then it could be duplicates
if (!fromQueries_.ContainsKey(key))
{
fromQueries_.Add(key, from as LogicFromQuery);
}
}
break;
case JoinQueryRef jref:
// We will form join group on all tables and put a filter on top
// of the joins as a normalized form for later processing.
//
// from a join b on a1=b1 or a3=b3 join c on a2=c2;
// => from a , b, c where (a1=b1 or a3=b3) and a2=c2;
//
LogicJoin subjoin = new LogicJoin(null, null);
Expr filterexpr = null;
for (int i = 0; i < jref.tables_.Count; i++)
{
LogicNode t = transformOneFrom(jref.tables_[i]);
var children = subjoin.children_;
if (children[0] is null)
{
children[0] = t;
}
else
{
if (children[1] is null)
{
children[1] = t;
}
else
{
subjoin = new LogicJoin(t, subjoin);
}
subjoin.type_ = jref.joinops_[i - 1];
filterexpr = filterexpr.AddAndFilter(jref.constraints_[i - 1]);
}
}
Debug.Assert(filterexpr != null);
from = new LogicFilter(subjoin, filterexpr);
break;
default:
throw new InvalidProgramException();
}
return(from);
}
LogicNode root;
if (from_.Count >= 2)
{
var join = new LogicJoin(null, null);
var children = join.children_;
from_.ForEach(x =>
{
LogicNode from = transformOneFrom(x);
if (children[0] is null)
{
children[0] = from;
}
else
{
children[1] = (children[1] is null) ? from :
new LogicJoin(from, children[1]);
}
});
root = join;
}
else if (from_.Count == 1)
{
root = transformOneFrom(from_[0]);
}
else
{
root = new LogicResult(selection_);
}
// distributed plan is required if any table is distributed, subquery
// referenced tables are not counted here. So we may have the query
// shape with main queyr not distributed but subquery is.
//
bool hasdtable = false;
bool onlyreplicated = true;
from_.ForEach(x => checkifHasdtableAndifOnlyReplicated(x, ref hasdtable, ref onlyreplicated));
if (hasdtable)
{
Debug.Assert(!distributed_);
distributed_ = true;
// distributed table query can also use memo
// remote exchange is considered in memo optimization
queryOpt_.optimize_.memo_use_remoteexchange_ = true;
if (onlyreplicated)
{
root = new LogicGather(root, new List <int> {
0
});
}
else
{
root = new LogicGather(root);
}
}
return(root);
}
// from clause -
// pair each from item with cross join, their join conditions will be handled
// with where clauss processing.
//
LogicNode transformFromClause()
{
LogicNode transformOneFrom(TableRef tab)
{
LogicNode from;
switch (tab)
{
case BaseTableRef bref:
from = new LogicScanTable(bref);
break;
case ExternalTableRef eref:
from = new LogicScanFile(eref);
break;
case QueryRef qref:
var plan = qref.query_.CreatePlan();
if (qref is FromQueryRef && queryOpt_.optimize_.remove_from_)
{
from = plan;
}
else
{
string alias = null;
if (qref is CTEQueryRef cq)
{
alias = cq.alias_;
}
else if (qref is FromQueryRef fq)
{
alias = fq.alias_;
}
var key = new NamedQuery(qref.query_, alias);
from = new LogicFromQuery(qref, plan);
subQueries_.Add(key);
// if from CTE, then it could be duplicates
if (!fromQueries_.ContainsKey(key))
{
fromQueries_.Add(key, from as LogicFromQuery);
}
}
break;
case JoinQueryRef jref:
// We will form join group on all tables and put a filter on top
// of the joins as a normalized form for later processing.
//
// from a join b on a1=b1 or a3=b3 join c on a2=c2;
// => from a , b, c where (a1=b1 or a3=b3) and a2=c2;
//
LogicJoin subjoin = new LogicJoin(null, null);
Expr filterexpr = null;
for (int i = 0; i < jref.tables_.Count; i++)
{
LogicNode t = transformOneFrom(jref.tables_[i]);
var children = subjoin.children_;
if (children[0] is null)
{
children[0] = t;
}
else
{
if (children[1] is null)
{
children[1] = t;
}
else
{
subjoin = new LogicJoin(t, subjoin);
}
subjoin.type_ = jref.joinops_[i - 1];
filterexpr = filterexpr.AddAndFilter(jref.constraints_[i - 1]);
}
}
Debug.Assert(filterexpr != null);
from = new LogicFilter(subjoin, filterexpr);
break;
default:
throw new Exception();
}
return(from);
}
LogicNode root;
if (from_.Count >= 2)
{
var join = new LogicJoin(null, null);
var children = join.children_;
from_.ForEach(x =>
{
LogicNode from = transformOneFrom(x);
if (children[0] is null)
{
children[0] = from;
}
else
{
children[1] = (children[1] is null) ? from :
new LogicJoin(from, children[1]);
}
});
root = join;
}
else if (from_.Count == 1)
{
root = transformOneFrom(from_[0]);
}
else
{
root = new LogicResult(selection_);
}
return(root);
}
