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--- db:redis [2014/07/31 16:57]
alfred [Execute]
+++ db:redis [2020/05/09 09:25] (actual)
@@ Línea 7: / Línea 7: @@
 $ cd <created folder>
 $ make
+$ make install
 </code>
 ==== Execute ====
@@ Línea 52: / Línea 53: @@
   * You can't create nested structures in Redis, meaning you can't (for example) store a native redis list inside a native redis hash-map. If you need nested structures, you might want to just store a JSON instead. Another option is to store an "id"/key to a different redis object as the value of the map key, but that requires multiple calls to the server to get the full object.
   * ''flushdb()'' will flush the database you are connected to (cleaning all the keys), while ''flushall()'' will clear all the keys in every database.
-  * Connecting/disconnecting for each operation is too expensive, so it is much better to maintain the connection opened. With redis-py it can be done by declaring a pool of connections (''ConnectionPool'' class). redis-py uses a connection pool to manage connections to a Redis server. By default, each Redis instance you create will in turn create its own connection pool. You can choose a concrete connection pool in the next way:
-<code python>
-pool = redis.ConnectionPool(host='localhost', port=6379, db=0)
-r = redis.Redis(connection_pool=pool)
-</code>
   * You can obtain the keys calling the ''keys()'' function of an ''StricRedis'' object. It also accept a pattern...
 <code python>
@@ Línea 63: / Línea 59: @@
 keys(pattern='*')
 </code>
-    * A ''Redis'' object has the ''info()'' to obtain information about Redis server like
+  * A ''Redis'' object has the ''info()'' to obtain information about Redis server like used memmory.
-===== Notes =====
+  * Other Redis methods...
+    * ''delete'' to delete an instance.
+==== DataTypes ====
+=== Strings ===
+<code python>
+>>> r.set('nombre', 'Jhon')
+True
+>>> r.set('apellido', 'Doe')
+True
+>>> r.set('nombre:codigo', '123ASDF')
+True
+>>> r.get('nombre')
+'Jhon'
+>>> r.get('nombre')
+'Doe'
+>>> r.get('nombre:codigo')
+ASDF
+</code>
+=== Lists ===
+<code python>
+>>> r.rpush('list', '1')
+L
+>>> r.rpush('list', '2')
+L
+>>> r.lrange('list', '0', '2')
+['1', '2']
+</code>
+=== Sets ===
+<code python>
+>>> r.sadd('conjunto', '1')
+
+>>> r.sadd('conjunto', '2')
+
+>>> r.smembers('conjunto')
+set(['1', '2', '23'])
+</code>
+=== Hashes ===
+<code python>
+>>> r.hset('mihash', 'field1', 'hola')
+L
+>>> r.hset('mihash', 'field2', 'mundo')
+L
+>>> r.hget('mihash', 'field1')
+'hola'
+>>> r.hgetall('mihash')
+{'field2': 'mundo', 'field1': 'hola'}
+</code>
+==== Connections ====
+Connecting/disconnecting for each operation is too expensive, so it is much better to maintain the connection opened. With redis-py it can be done by declaring a pool of connections (''ConnectionPool'' class). redis-py uses a connection pool to manage connections to a Redis server. By default, each Redis instance you create will in turn create its own connection pool. You can choose a concrete connection pool in the next way:
+<code python>
+pool = redis.ConnectionPool(host='localhost', port=6379, db=0)
+r = redis.Redis(connection_pool=pool)
+</code>
+==== Pipelines ====
+Pipelines provide support for buffering multiple commands to the server in a single request. They can be used to dramatically increase the performance.
+<code python>
+>>> r = redis.Redis(...)
+>>> r.set('bing', 'baz')
+>>> # Use the pipeline() method to create a pipeline instance
+>>> pipe = r.pipeline()
+>>> # The following SET commands are buffered
+>>> pipe.set('foo', 'bar')
+>>> pipe.get('bing')
+>>> # the EXECUTE call sends all buffered commands to the server, returning
+>>> # a list of responses, one for each command.
+>>> pipe.execute()
+[True, 'baz']
+</code>
+For ease of use, all commands being buffered into the pipeline return the pipeline object itself. Therefore calls can be chained like:
+<code python>
+>>> pipe.set('foo', 'bar').sadd('faz', 'baz').incr('auto_number').execute()
+[True, True, 6]
+</code>
+With pipelines commands are executed atomically as a group by default. To disable the atomicity but still buffer commands, it's possible to turn off transactions.
+<code python>
+>>> pipe = r.pipeline(transaction=False)
+</code>
+==== Publish\Subscribe ====
+PubSub object subscribes to channels and listens for new messages. Once a PubSub instance is created, channels and patterns can be subscribed to.
+<code python>
+>>> r = redis.StrictRedis(...)
+>>> p = r.pubsub()
+>>> p.subscribe('my-first-channel', 'my-second-channel', ...)
+>>> p.psubscribe('my-*', ...)
+</code>
+To send and receive message...
+<code python>
+>>> r.publish('my-first-channel', 'some data')
+>>> p.get_message()
+{'channel': 'my-first-channel', 'data': 'some data', 'pattern': None, 'type': 'message'}
+>>> p.get_message()
+{'channel': 'my-first-channel', 'data': 'some data', 'pattern': 'my-*', 'type': 'pmessage'}
+</code>
+Every message read from a PubSub instance will be a dictionary with the following keys.
+  * type: One of the following: 'subscribe', 'unsubscribe', 'psubscribe', 'punsubscribe', 'message', 'pmessage'
+  * channel: The channel [un]subscribed to or the channel a message was published to
+pattern: The pattern that matched a published message's channel. Will be None in all cases except for 'pmessage' types.
+  * data: The message data. With [un]subscribe messages, this value will be the number of channels and patterns the connection is currently subscribed to. With [p]message messages, this value will be the actual published message.
+Unsubscribing works just like subscribing. If no arguments are passed to [p]unsubscribe, all channels or patterns will be unsubscribed from.
+<code python>
+>>> p.unsubscribe()
+>>> p.punsubscribe('my-*')
+</code>
+redis-py also allows you to register callback functions to handle published messages. Message handlers take a single argument, the message, which is a dictionary just like the examples above. To subscribe to a channel or pattern with a message handler, pass the channel or pattern name as a keyword argument with its value being the callback function.
+<code python>
+>>> def my_handler(message):
+...     print 'MY HANDLER: ', message['data']
+>>> p.subscribe(**{'my-channel': my_handler})
+</code>
+If your application is not interested in the (sometimes noisy) subscribe/unsubscribe confirmation messages, you can ignore them by passing ''ignore_subscribe_messages=True'' to r.pubsub().
+==== Notes ====
+  * redis-py can be used together with ''Redis Sentinel'' to discover Redis nodes.
+===== Notes =====
+  * A good GUI: [[http://redisdesktop.com/]]

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