Oracle - Vistas de Diccionarios de datos

V$CIRCUIT

V$CIRCUIT contains information about virtual circuits, which are user connections to the database through dispatchers and servers.

Column	Datatype	Description
CIRCUIT	RAW(4 | 8)	Circuit address
DISPATCHER	RAW(4 | 8)	Current dispatcher process address
SERVER	RAW(4 | 8)	Current server process address
WAITER	RAW(4 | 8)	Address of the server process that is waiting for the (currently busy) circuit to become available
SADDR	RAW(4 | 8)	Address of the session bound to the circuit
STATUS	VARCHAR2(16)	Status of the circuit: BREAK - currently interrupted EOF - about to be removed OUTBOUND - an outward link to a remote database NORMAL - normal circuit into the local database
QUEUE	NUMBER	Queue the circuit is currently on: COMMON - on the common queue, waiting to be picked up by a server process DISPATCHER - waiting for the dispatcher SERVER - currently being serviced NONE - idle circuit
MESSAGE0	NUMBER	Size in bytes of the messages in the first message buffer
MESSAGE1	NUMBER	Size in bytes of the messages in the second message buffer
MESSAGE2	NUMBER	Size in bytes of the messages in the third message buffer
MESSAGE3	NUMBER	Size in bytes of the messages in the fourth message buffer
MESSAGES	NUMBER	Total number of messages that have gone through this circuit
BYTES	NUMBER	Total number of bytes that have gone through this circuit
BREAKS	NUMBER	Total number of breaks (interruptions) for this circuit
PRESENTATION	VARCHAR2(257)	Presentation protocol used by the client and server
PCIRCUIT	RAW(4 | 8)	Address of the parent circuit

V$SHARED_SERVER

This view contains information on the shared server processes.

Column	Datatype	Description
NAME	VARCHAR2(4)	Name of the server
PADDR	RAW(4 | 8)	Server's process address
STATUS	VARCHAR2(16)	Server status: EXEC - Executing SQL WAIT (ENQ) - Waiting for a lock WAIT (SEND) - Waiting to send data to user WAIT (COMMON) - Idle; waiting for a user request WAIT (RESET) - Waiting for a circuit to reset after a break
MESSAGES	NUMBER	Number of messages processed
BYTES	NUMBER	Total number of bytes in all messages
BREAKS	NUMBER	Number of breaks
CIRCUIT	RAW(4 | 8)	Address of circuit currently being serviced
IDLE	NUMBER	Total idle time (in hundredths of a second)
BUSY	NUMBER	Total busy time (in hundredths of a second)
REQUESTS	NUMBER	Total number of requests taken from the common queue in this server's lifetime

V$DISPATCHER

V$DISPATCHER displays information about the dispatcher processes.

Column	Datatype	Description
NAME	VARCHAR2(4)	Name of the dispatcher process
NETWORK	VARCHAR2(128)	Network address of the dispatcher
PADDR	RAW(4 | 8)	Process address
STATUS	VARCHAR2(16)	Status of the dispatcher: WAIT - Idle SEND - Sending a message RECEIVE - Receiving a message CONNECT - Establishing a connection DISCONNECT - Handling a disconnect request BREAK - Handling a break TERMINATE - In the process of terminating ACCEPT - Accepting connections (no further information available) REFUSE - Rejecting connections (no further information available)
ACCEPT	VARCHAR2(3)	Indicates whether the dispatcher is accepting new connections (YES) or not (NO)
MESSAGES	NUMBER	Number of messages processed by the dispatcher
BYTES	NUMBER	Size (in bytes) of messages processed by the dispatcher
BREAKS	NUMBER	Number of breaks occurring in the connection
OWNED	NUMBER	Number of circuits owned by the dispatcher
CREATED	NUMBER	Number of circuits created by the dispatcher
IDLE	NUMBER	Total idle time for the dispatcher (in hundredths of a second)
BUSY	NUMBER	Total busy time for the dispatcher (in hundredths of a second)
LISTENER	NUMBER	Most recent Oracle error number the dispatcher received from the listener
CONF_INDX	NUMBER	Zero-based index of the DISPATCHERS configuration used by the dispatcher

V$SHARED_SERVER_MONITOR

This view contains information for tuning the shared server.

Column	Datatype	Description
MAXIMUM_CONNECTIONS	NUMBER	Highest number of virtual circuits in use at one time since the instance started. If this value reaches the value set for the CIRCUITS initialization parameter, then consider raising the value of CIRCUITS.
MAXIMUM_SESSIONS	NUMBER	Highest number of shared server sessions in use at one time since the instance started. If this reaches the value set for the SHARED_SERVER_SESSIONS initialization parameter, then consider raising the value of SHARED_SERVER_SESSIONS.
SERVERS_STARTED	NUMBER	Total number of shared servers started since the instance started (but not including those started during startup)
SERVERS_TERMINATED	NUMBER	Total number of shared servers stopped by Oracle since the instance started
SERVERS_HIGHWATER	NUMBER	Highest number of servers running at one time since the instance started. If this value reaches the value set for the MAX_SHARED_SERVERS initialization parameter, then consider raising the value of SHARED_SERVERS.

V$QUEUE

V$QUEUE contains information on the shared server message queues.

Column	Datatype	Description
PADDR	RAW(4 | 8)	Address of the process that owns the queue
TYPE	VARCHAR2(10)	Type of queue: COMMON - Processed by servers DISPATCHER
QUEUED	NUMBER	Number of items in the queue
WAIT	NUMBER	Total time that all items in this queue have waited (in hundredths of a second). Divide by TOTALQ for average wait per item.
TOTALQ	NUMBER	Total number of items that have ever been in the queue

Como usar Tiles con aplicaciones JavaServerFaces

Lo que se tiene que hacer es agregar el archivo struts.jar de la distribución de los 1.1 de Struts a la ruta de clases. Incluir struts.jar no significa que Struts es necesario para utilizar JSF con Tiles. Es que el paquete se distribuye dentro del archivo struts.jar. No hay otras funcionalidades de la infraestructura de Struts que se trataran.

Algunos consejos útiles.

1.- Aquí está un fragmento del archivo web.xml que habilita Tiles:

<servlet>
   <servlet-name>Faces Servlet</servlet-name>
   <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
   <load-on-startup>1</load-on-startup>
</servlet>
<servlet>
   <servlet-name>TilesServet</servlet-name>
   <servlet-class>org.apache.struts.tiles.TilesServlet</servlet-class>
   <init-param>
      <param-name>definitions-config</param-name>
      <param-value>/WEB-INF/tiles-defs.xml</param-value>
   </init-param>
   <load-on-startup>2</load-on-startup>
</servlet>

Pon atención al Tag load-on-startup tag. El servlet Tiles debe ser leído después del server Faces. ¡Esto es importante!

2.- tiles-defs-xml es el nombre del archivo estándar para el archivo de definiciones de Tiles. Sin embargo puedes nombrarlo de la manera que desees y usar mas de uno. Sepáralos por coma para definir tales archivos en el parametro definitions-config en el archivo web.xml.

3.- Establece flush="false" para las etiquetas tiles:insert si los usas dentro de un elemento f:view (entre las etiquetas de inicio y fin de f:view).

4.- Usa la etiqueta f:subview si esta usando tiles dentro de un elemento f:facet, por ejemplo:

<f:facet name="header">
  <f:subview id="header">
    <tiles:insert definition="page.header" flush="false"/>
  </f:subview>
</f:facet>

5.- Nunca incluya un elemento f:view dentro de otro elemento f:view.

6.- No puedes hacer un forward directamente en los Tiles, como en Struts. El archivo faces-config debe referenciar a las paginas usando Tiles como vistas.