Should I use hash or btree for a foreign key index in postgresql 9.3? -

-

Which index would perform better for the foreign key of type integer in postgresql 9.3?

I have a hash index because foreign key comparison is always made

Or does a BTRE compare faster as a hash in use for Johns on foreign keys?

Because using the PostGracekey primary key, Btree suggests that they are even better for foreign keys.

From:

Caution Hash Index Operation Currently Val-Log , The hash index may have to be recreated with REINDEX after the database crashes, if unwritten changes occur, in addition to that, changes in the hash index are not repeated on the streaming or file-based replication after the initial base backup , So they give wrong answers to those questions which Not use them. For these reasons, use of hash index is currently discouraged.

There is no evidence that there is a benefit on BT ree in a hash index.

Comments

Post a Comment

Popular posts from this blog

java - ImportError: No module named py4j.java_gateway -

-
I'm trying to call the Python using the Java program py4j . I've been installing the plug-in Eclipse and test name Piidvi project. I'm trying to execute the following part of the code found on py4j webpage: Import from py4j.java_gateway to JavaGateway, java_import gateway = JavaGateway () jvm = gateway.jvm java_import (jvm, '' Org.eclipse Kkorkrisorsej. * ") Vrkspes_rut = Jvankresourkesplginkgetvrkspas (). GetRoot (Gateway .help (workspace_root, '* Projects *') project_names = [project.getName () (for projects workpace_root.getProjects))] print (Projekt_nam) But I There is an error in import. I have checked that the P4JJ is present in the Jar Eclipse plugin directory. Can anyone help please? I had to install the py4j application
Read more

python - Receiving "KeyError" after decoding json result from url -

-
I am new to Python I am trying to parse JSON result from a URL. Basically, I was using the following: response = urllib.request.urlopen (url) json_obj = json.load (response) It should be a stroke "str 'not' bytes' in the lines of a given" JSON object, so after searching on the StackoverView Flo, I decode the response in this way: F = urllib.request.urlopen (Url) charset = f.info (). Get_param ('charset', 'utf8') data = f.read () decoded = json.loads (data.decode (charset)) If I print "decode" I is as follows: { 'link': { 'summary data': 'https: // localhost / piwebapi / streams / p0_7qHaW4UHU-RlCaz8tpasAAQAAAAU0hJTExNQU42NDIwXFNJTlVTT0lE / summary' 'value': 'https: // localhost / Piwebapi / streams / P0_7qHaW4UHU-RlCaz8tpasAAQAAAAU0hJTExNQU42NDIwXFNJTlVTT0lE / price ',' InterpolatedData ':' https: // localhost / Piwebapi / streams / P0_7qHaW4UHU-RlCaz8tpasAAQAAAAU0hJTE...
Read more

.net - Creating a new Queue Manager and Queue in Websphere MQ (using C#) -

-
"itemprop =" text "> I am writing applications that use WebSphere MQ to send messages. My unittests (for flow), I want to verify that I have put the correct message on the response queue. I am trying to figure out how to do this. My main obstacle is that I think it might be scary to clear the queue before running in my queue because the same queue can be used by other applications, I thought a decent solution would be a new line The manager will remove the queue for my solidarity and after using it. So my question is: Is it possible to use C # by using queue manager and queue? After the For future reference and future people, who want to make queues. I thought how to make and remove IBM MQ QE (not quenhers) with PCM messaging. It is not very simple, but it can be done. We have implemented it in a library and it is being used to create and delete commands before and after integration tests. The most important part of the code in this library is shown in the...
Read more