public static SchemaFile loadSchemaFile(String sgName, int schemaRegionId)
      throws IOException, MetadataException {
    return new SchemaFile(sgName, schemaRegionId, false, -1L, false);
  }
This class is mainly aimed to manage space all over the file.

<p>This class is meant to open a .pst(Persistent mTree) file, and maintains the header of the
file. It Loads or writes a page length bytes at once, with an 32 bits int to index a page inside
a file. Use SlottedFile to manipulate segment(sp) inside a page(an array of bytes).
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/schemaregion/mtree/impl/pbtree/schemafile/SchemaFile.java