docs: Table SYSTEM_SESSIONS() {
  
          Table t = sysTables[SYSTEM_SESSIONS];
  
          if (t == null) {
              t = createBlankTable(sysTableHsqlNames[SYSTEM_SESSIONS]);
  
              addColumn(t, "SESSION_ID", CARDINAL_NUMBER);
              addColumn(t, "CONNECTED", TIME_STAMP);
              addColumn(t, "USER_NAME", SQL_IDENTIFIER);
              addColumn(t, "IS_ADMIN", Type.SQL_BOOLEAN);
              addColumn(t, "AUTOCOMMIT", Type.SQL_BOOLEAN);
              addColumn(t, "READONLY", Type.SQL_BOOLEAN);
              addColumn(t, "MAXROWS", CARDINAL_NUMBER);
  
              // Note: some sessions may have a NULL LAST_IDENTITY value
              addColumn(t, "LAST_IDENTITY", CARDINAL_NUMBER);
              addColumn(t, "TRANSACTION_SIZE", CARDINAL_NUMBER);
              addColumn(t, "SCHEMA", SQL_IDENTIFIER);
  
              // order:  SESSION_ID
              // true primary key
              HsqlName name = HsqlNameManager.newInfoSchemaObjectName(
                  sysTableHsqlNames[SYSTEM_SESSIONS].name, false,
                  SchemaObject.INDEX);
  
              t.createPrimaryKey(name, new int[]{ 0 }, true);
  
              return t;
          }
  
          // column number mappings
          final int isid      = 0;
          final int ict       = 1;
          final int iuname    = 2;
          final int iis_admin = 3;
          final int iautocmt  = 4;
          final int ireadonly = 5;
          final int imaxrows  = 6;
          final int ilast_id  = 7;
          final int it_size   = 8;
          final int it_schema = 9;
  
          //
          PersistentStore store = database.persistentStoreCollection.getStore(t);
  
          // intermediate holders
          Session[] sessions;
          Session   s;
          Object[]  row;
  
          // Initialisation
          sessions = ns.listVisibleSessions(session);
  
          // Do it.
          for (int i = 0; i < sessions.length; i++) {
              s              = sessions[i];
              row            = t.getEmptyRowData();
              row[isid]      = ValuePool.getLong(s.getId());
              row[ict]       = new TimestampData(s.getConnectTime() / 1000);
              row[iuname]    = s.getUsername();
              row[iis_admin] = ValuePool.getBoolean(s.isAdmin());
              row[iautocmt]  = ValuePool.getBoolean(s.isAutoCommit());
              row[ireadonly] = ValuePool.getBoolean(s.isReadOnlyDefault());
              row[imaxrows]  = ValuePool.getInt(s.getSQLMaxRows());
              row[ilast_id] =
                  ValuePool.getLong(((Number) s.getLastIdentity()).longValue());
              row[it_size]   = ValuePool.getInt(s.getTransactionSize());
              row[it_schema] = s.getCurrentSchemaHsqlName().name;
  
              t.insertSys(store, row);
          }
  
          return t;
      }