// 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:
from = new LogicScanTable(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 =>
{
if (x is BaseTableRef bx)
{
var method = bx.Table().distMethod_;
if (bx.IsDistributed())
{
hasdtable = true;
if (method != TableDef.DistributionMethod.Replicated)
{
onlyreplicated = false;
}
}
}
});
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);
}
public LogicMarkJoin(LogicNode l, LogicNode r, Expr f) : base(l, r, f)
{
type_ = JoinType.Left;
}
// If there is OR in the predicate, can't turn into a filter
//
LogicNode existsToMarkJoin(LogicNode nodeA, ExistSubqueryExpr existExpr, ref bool canReplace)
{
bool exprIsNotORExprAndEqualsToExistExpr(Expr x, Expr existExpr)
{
return((!(x is LogicOrExpr)) && x.Equals(existExpr));
}
// nodeB contains the join filter
var nodeB = existExpr.query_.logicPlan_;
var nodeBFilter = nodeB.filter_;
nodeB.NullifyFilter();
// nullify nodeA's filter: the rest is push to top filter. However,
// if nodeA is a Filter|MarkJoin, keep its mark filter.
var markerFilter = new ExprRef(new MarkerExpr(nodeBFilter.tableRefs_, existExpr.subqueryid_), 0);
var nodeAFilter = nodeA.filter_;
Debug.Assert(!(nodeA is null));
// a1 > @1 and a2 > @2 and a3 > 2, existExpr = @1
// keeplist: a1 > @1 and a3 > 2
// andlist after removal: a2 > @2
// nodeAFilter = a1 > @1 and a3 > 2
// consider a1>0 and (@1 or @2)
// a1>0 and (@1 or (@2 and @3))
//(@1 or marker@2) and marker@3 existExpr = @1
// keep list (@1 or marker@2)
// andlist after remove @3
// nodeAFilter = (@1 or marker@2)
var andlist = nodeAFilter.FilterToAndList();
var keeplist = andlist.Where(x => x.VisitEachExists(e => e.Equals(existExpr))).ToList();
andlist.RemoveAll(x => exprIsNotORExprAndEqualsToExistExpr(x, existExpr) ||
((x is LogicOrExpr) && !hasAnyExtraSubqueryExprInOR(x, existExpr)));
// if there is any (#marker@1 or @2), the root should be replace,
// i.e. the (#marker@1 or @2) keeps at the top for farther unnesting
canReplace = andlist.Find(x => (x is LogicOrExpr) && hasAnyExtraSubqueryExprInOR(x, existExpr)) == null ? false : true;
if (andlist.Count == 0 || canReplace)
{
// nodeA is root, a ref parameter. (why it is a ref parameter without "ref" or "out" )
nodeA.NullifyFilter();
}
else
{
nodeA.filter_ = andlist.AndListToExpr();
nodeAFilter = keeplist.Count > 0 ? keeplist.AndListToExpr() : markerFilter;
}
// make a mark join
LogicMarkJoin markjoin;
if (existExpr.hasNot_)
{
markjoin = new LogicMarkAntiSemiJoin(nodeA, nodeB, existExpr.subqueryid_);
}
else
{
markjoin = new LogicMarkSemiJoin(nodeA, nodeB, existExpr.subqueryid_);
}
// make a filter on top of the mark join collecting all filters
Expr topfilter;
topfilter = nodeAFilter.SearchAndReplace(existExpr, markerFilter);
nodeBFilter.DeParameter(nodeA.InclusiveTableRefs());
// find all expr contains Parameter col and move it to the toper
var TableRefs = nodeA.InclusiveTableRefs();
topfilter = topfilter.AddAndFilter(nodeBFilter);
LogicFilter Filter = new LogicFilter(markjoin, topfilter);
var notDeparameterExpr = findAndfetchParameterExpr(ref nodeA);
if (notDeparameterExpr.Count > 0)
{
topfilter = notDeparameterExpr.AndListToExpr();
Filter = new LogicFilter(Filter, topfilter);
}
return(Filter);
}
public LogicMarkJoin(LogicNode l, LogicNode r, int subquery_id) : base(l, r)
{
type_ = JoinType.Left; subquery_id_ = subquery_id;
}
// 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);
}
