protected function loadTableIndexes($tableName)
    {
        static $sql = <<<'SQL'
SELECT
    "ic"."relname" AS "name",
    "ia"."attname" AS "column_name",
    "i"."indisunique" AS "index_is_unique",
    "i"."indisprimary" AS "index_is_primary"
FROM "pg_class" AS "tc"
INNER JOIN "pg_namespace" AS "tcns"
    ON "tcns"."oid" = "tc"."relnamespace"
INNER JOIN "pg_index" AS "i"
    ON "i"."indrelid" = "tc"."oid"
INNER JOIN "pg_class" AS "ic"
    ON "ic"."oid" = "i"."indexrelid"
INNER JOIN "pg_attribute" AS "ia"
    ON "ia"."attrelid" = "i"."indrelid" AND "ia"."attnum" = ANY ("i"."indkey")
WHERE "tcns"."nspname" = :schemaName AND "tc"."relname" = :tableName
ORDER BY "ia"."attnum" ASC
SQL;

        $resolvedName = $this->resolveTableName($tableName);
        $indexes = $this->db->createCommand($sql, [
            ':schemaName' => $resolvedName->schemaName,
            ':tableName' => $resolvedName->name,
        ])->queryAll();
        $indexes = $this->normalizePdoRowKeyCase($indexes, true);
        $indexes = ArrayHelper::index($indexes, null, 'name');
        $result = [];
        foreach ($indexes as $name => $index) {
            $result[] = new IndexConstraint([
                'isPrimary' => (bool) $index[0]['index_is_primary'],
                'isUnique' => (bool) $index[0]['index_is_unique'],
                'name' => $name,
                'columnNames' => ArrayHelper::getColumn($index, 'column_name'),
            ]);
        }

        return $result;
    }
protected function loadTableIndexes($tableName)
    {
        static $sql = <<<'SQL'
SELECT
    "ic"."relname" AS "name",
    "ia"."attname" AS "column_name",
    "i"."indisunique" AS "index_is_unique",
    "i"."indisprimary" AS "index_is_primary"
FROM "pg_class" AS "tc"
INNER JOIN "pg_namespace" AS "tcns"
    ON "tcns"."oid" = "tc"."relnamespace"
INNER JOIN "pg_index" AS "i"
    ON "i"."indrelid" = "tc"."oid"
INNER JOIN "pg_class" AS "ic"
    ON "ic"."oid" = "i"."indexrelid"
INNER JOIN "pg_attribute" AS "ia"
    ON "ia"."attrelid" = "i"."indrelid" AND "ia"."attnum" = ANY ("i"."indkey")
WHERE "tcns"."nspname" = :schemaName AND "tc"."relname" = :tableName
ORDER BY "ia"."attnum" ASC
SQL;

        $resolvedName = $this->resolveTableName($tableName);
        $indexes = $this->db->createCommand($sql, [
            ':schemaName' => $resolvedName->schemaName,
            ':tableName' => $resolvedName->name,
        ])->queryAll();
        $indexes = $this->normalizePdoRowKeyCase($indexes, true);
        $indexes = ArrayHelper::index($indexes, null, 'name');
        $result = [];
        foreach ($indexes as $name => $index) {
            $result[] = new IndexConstraint([
                'isPrimary' => (bool) $index[0]['index_is_primary'],
                'isUnique' => (bool) $index[0]['index_is_unique'],
                'name' => $name,
                'columnNames' => ArrayHelper::getColumn($index, 'column_name'),
            ]);
        }

        return $result;
    }
{@inheritdoc}