On the list of indexes of a table show which were created as part of the creation of a constraint

The explicit column is true when the index was manually created
In SQL only a comment is given that the index was implicitly created

pglab/IndexModel.cpp

@@ -36,10 +36,17 @@ int IndexModel::columnCount(const QModelIndex &/*parent*/) const
 	return colCount;
 }
 
-Oid IndexModel::getType(int /*column*/) const
+Oid IndexModel::getType(int column) const
 {
+    switch (column) {
+    case SizeCol:
+        return Pgsql::int8_oid;
+    case ExplicitIndexCol:
+        return Pgsql::bool_oid;
+    default:
         return Pgsql::varchar_oid;
     }
+}
 
 QVariant IndexModel::headerData(int section, Qt::Orientation orientation, int role) const
 {
@@ -66,6 +73,9 @@ QVariant IndexModel::headerData(int section, Qt::Orientation orientation, int ro
             case SizeCol:
                 c = tr("Size");
                 break;
+            case ExplicitIndexCol:
+                c = tr("Explicit");
+                break;
 //			case DefinitionCol:
 //				c = tr("Definition");
 //				break;
@@ -106,6 +116,9 @@ QVariant IndexModel::getData(const QModelIndex &index) const
     case SizeCol:
         v = dat.sizeBytes;
         break;
+    case ExplicitIndexCol:
+        v = !dat.isSupportingIndex();
+        break;
 	}
 	return v;
 }

pglab/IndexModel.h

@@ -23,6 +23,7 @@ public:
 		ColumnsCol, ///
 		ConditionCol,
         SizeCol,
+        ExplicitIndexCol,
 		colCount };
 
 // oid

pglablib/catalog/PgConstraintContainer.cpp

@@ -57,9 +57,6 @@ std::vector<PgConstraint> PgConstraintContainer::getFKeyForTableColumn(Oid relid
 std::vector<PgConstraint> PgConstraintContainer::getConstraintsForRelation(Oid relid) const
 {
 	std::vector<PgConstraint> result;
-//	for (const auto &e : m_container)
-//		if (e.relid == relid)
-//			result.push_back(e);
 	std::copy_if(m_container.begin(), m_container.end(), std::back_inserter(result),
 				 [relid] (auto && item) { return item.relid == relid; });
 	return result;
@@ -80,10 +77,15 @@ std::optional<PgConstraint> PgConstraintContainer::getPrimaryForRelation(Oid rel
 std::vector<PgConstraint> PgConstraintContainer::getReferencedForRelation(Oid relid) const
 {
 	std::vector<PgConstraint> result;
-//	for (const auto &e : m_container)
-//		if (e.frelid == relid)
-//			result.push_back(e);
     std::copy_if(m_container.begin(), m_container.end(), std::back_inserter(result),
 				 [relid] (auto && item) { return item.frelid == relid; });
     return result;
 }
+
+std::vector<PgConstraint> PgConstraintContainer::getSupportedByIndex(Oid indexrelid) const
+{
+    std::vector<PgConstraint> result;
+    std::copy_if(m_container.begin(), m_container.end(), std::back_inserter(result),
+                 [indexrelid] (auto && item) { return item.indid == indexrelid; });
+    return result;
+}

pglablib/catalog/PgConstraintContainer.h

@@ -18,6 +18,7 @@ public:
 	std::vector<PgConstraint> getConstraintsForRelation(Oid relid) const;
 	std::optional<PgConstraint> getPrimaryForRelation(Oid relid) const;
 	std::vector<PgConstraint> getReferencedForRelation(Oid relid) const;
+    std::vector<PgConstraint> getSupportedByIndex(Oid indexrelid) const;
 protected:
 	virtual PgConstraint loadElem(const Pgsql::Row &row) override;
 };

pglablib/catalog/PgIndex.cpp

@@ -1,6 +1,8 @@
 #include "PgIndex.h"
 #include "PgDatabaseCatalog.h"
 #include "PgClassContainer.h"
+#include "PgConstraint.h"
+#include "PgConstraintContainer.h"
 #include "PgAmContainer.h"
 #include <QStringBuilder>
 
@@ -19,6 +21,8 @@ QString PgIndex::getAm() const
 
 QString PgIndex::createSql() const
 {
+    if (isSupportingIndex())
+        return "-- implicitly created index";
 	return definition + ";";
 
 	//	const PgClass *table_class = catalog.classes()->getByKey(index.relid);
@@ -69,6 +73,9 @@ QString PgIndex::createSql() const
 
 QString PgIndex::dropSql() const
 {
+    if (isSupportingIndex())
+        return "-- implicitly created index";
+
     QString result;
 	result = "DROP INDEX "
 			% fullyQualifiedQuotedObjectName()
@@ -80,3 +87,17 @@ QString PgIndex::typeName() const
 {
     return "INDEX";
 }
+
+bool PgIndex::isSupportingIndex() const
+{
+    // This function looks at the supporting index for constaints but this is not completely the
+    // same thing. For example a fkey is supported by a unique constraint on the referred table but this
+    // index has not been created as part of the constraint creation so it does not count.
+    //
+    // For now we assume that when the constraint and index are on the same table the index was created
+    // implicitly.
+
+    auto c = catalog().constraints()->getSupportedByIndex(oid());
+    auto find_result = std::find_if(c.begin(), c.end(), [this] (auto && item) { return item.relid == relid; });
+    return (find_result != c.end());
+}

pglablib/catalog/PgIndex.h

@@ -9,7 +9,6 @@
 class PgIndex : public PgNamespaceObject {
 public:
 
-//	Oid indexrelid = InvalidOid; // oid of pg_class for this index
 	Oid relid = InvalidOid; // oid of table (pg_class) where this is an index on
 	int16_t natts = 0;
 	bool isunique = false;
@@ -34,15 +33,14 @@ public:
 	using PgNamespaceObject::PgNamespaceObject;
 	QString getAm() const;
 
-//	bool operator==(Oid _oid) const { return indexrelid == _oid; }
+    QString createSql() const override;
-//	//bool operator==(const QString &n) const { return name == n; }
+    QString dropSql() const override;
-//	bool operator<(Oid _oid) const { return indexrelid < _oid; }
-//	bool operator<(const PgIndex &rhs) const { return indexrelid < rhs.indexrelid; }
-
-	QString createSql() const;
-	QString dropSql() const;
 
 	QString typeName() const override;
+
+    /// Returns true when this index has been created as part of the creation
+    /// of a constaint.
+    bool isSupportingIndex() const;
 };
 
 #endif // PGINDEX_H