Is query tracing on Postgresql possible? I am using 9.0 on windows with OLEDB interface.
Also, I need it to be in real-time, not buffered like it is by default...
I assume you mean tracing the statements on the server side?
In that case, change the parameter log_min_duration to 0 in postgresql.conf.
You don't need to restart the server, just reload the configuration (pg_ctl reload)
Related
I am running long queries on managed PostgreSQL server instances. Since I have no access to the underlying OS I need to use a client (DBeaver or PGAdmin etc) on my local laptop to run queries. I's like to avoid my queries from stopping when I have an internet outage and also avoid having to leave my laptop on for hours just to maintain a connection.
With MS SQl Server, I used SQLAgent to run the queries directly on the server and so could shut down my laptop and the queries would carry on without issue.
Is there a way to trigger a query to run independently from the client admin software that triggered it?
Thanks
No, that is not possible, unless you have a third-party extension like pg_timetable or pg_cron installed.
I am using ORACLE database in a windows environment and running a JSP/servlet web application in tomcat. After I do some operations with the application it gives me the following error.
ORA-12518, TNS: listener could not hand off client connection
can any one help me to identify the reason for this problem and propose me a solution?
The solution to this question is to increase the number of processes :
1. Open command prompt
2. sqlplus / as sysdba; //login sysdba user
3. startup force;
4. show parameter processes; // This shows 150(some default) processes allocated, then increase the count to 800
5. alter system set processes=800 scope=spfile;
As Tried and tested.
In my case I found that it is because I haven't closed the database connections properly in my application. Too many connections are open and Oracle can not make more connections. This is a resource limitation. Later when I check with oracle forum I could see some reasons that have mentioned there about this problem. Some of them are.
In most cases this happens due to a network problem.
Your server is probably running out of memory and need to swap memory to disk.One cause can be an Oracle process consuming too much memory.
if it is the second one, please verify large_pool_size or check dispatcher were enough for all connection.
You can refer bellow link for further details.
https://community.oracle.com/message/1874842#1874842
I ran across the same problem, in my case it was a new install of the Oracle client on a new desktop that was giving the error, other clients were working so I knew it wouldn't be a fix to the database configuration. tnsping worked properly but sqlplus failed with the ora-12518 listener error.
I had the tnsnames.ora entry with a SID instead of a service_name, then once I fixed that, still the same error and found I had the wrong service_name as well. Once I fixed that, the error went away.
If from one day to another the issue shows for no apparent reasons, add these following lines at the bottom of the listner.ora file. If your oracle_home environment variable is set like this:
(ORACLE_HOME = C:\oracle11\app\oracle\product\11.2.0\server)
The lines to add are:
ADR_BASE_LISTENER = C:\oracle11\app\oracle\
DIRECT_HANDOFF_TTC_LISTENER=OFF
I had the same problem when executing queries in my application. I'm using Oracle client with Ruby on Rails.
The problem started when I accidentally started several connections with the DB and didn't close them.
When I fixed this, everything started to work fine again.
Hope this helps another one with the same problem.
I experienced the same error after upgrading to Windows 10. I solved it by starting services for Oracle which are stopped.
Start all the services as shown in the following image:
I had the same issue. After restarting all Oracle services it worked again.
same problem encountered for me.
And from oracle server listener log, can see more information.
and I found that the SERVICE_NAME is not match the tnsnames.ora configured Service name. so I changed the application's data source configuration from SID value to Service_NAME value and it fixed.
23-MAY-2019 02:44:21 * (CONNECT_DATA=(CID=(PROGRAM=JDBC Thin Client)(HOST=__jdbc__)(USER=XXXXXX$))(SERVICE_NAME=orclaic)) * (ADDRESS=(PROTOCOL=tcp)(HOST=::1)(PORT=50818)) * establish * orclaic * 12518
TNS-12518: TNS:listener could not hand off client connection
TNS-12560: TNS:protocol adapter error
TNS-00530: Protocol adapter error
64-bit Windows Error: 203: Unknown error
I had the same issue in real time application and the issue gone by itself next day. upon checking, it was found that server ran out of memory due to additional processes running.
So in my case, the reason was server run out of memory
first of all
check the listener log
check the show parameter processes vs select count(*) from v$processes;
increase the process, it may require SGA increase
;
I am in the middle of developing a C extension library for PostgreSQL. I am using a lot of ereport() calls to help with future debugging.
A typical example of usage in my code would be something like this:
ereport(NOTICE, (errmsg("[%s]: Returned nonzero result (%d).", (const char*)__FUNCTION__, ret)) );
However, when I look in /var/log/postgresql/postgresql-8.4-main.log my messages do not seem to be appearing there - only messages from what I assume is the db server daemon.
So, where are my log messages being stored?
BTW, I am running PG 8.4 on Ubuntu Linux (10.0.4)
By default, logging of non-critical messages is not enabled on fresh installs. You configure it by setting log_destination and logging_collector.
PostgreSQL has several logging levels, and by default, NOTICE level is not saved to log files (even when they are enabled) . This is configured by log_min_messages setting. However NOTICE it emitted to client by default. This is configured by client_min_messages setting.
So if you want these to be stored in log files, you will have to either change NOTICE to WARNING in your code, or set log_min_messages = notice.
See this http://www.postgresql.org/docs/8.4/static/runtime-config-logging.html
and maybe this http://www.depesz.com/index.php/2011/05/06/understanding-postgresql-conf-log/
I've been trying for quite some time to use Entity Framework with our IBM Informix databases. Hours of searching has pointed me towards installing the IBM .NET Data Server Provider, which I have installed, however when I attempt to add a new Entity Model to my project I only have the Microsoft SQL Server Data Providers listed. Am I missing a step? Is this even possible?
I am not an expert on Windows or .NET; treat any comments I make with due caution.
Installing the .NET Data Server Provider is an important first step. You now have to make sure that you can use it to connect to the Informix databases you want to manipulate. There are several things you'll need to check here:
Is the server (meaning the Informix instance) configured to allow DRDA connections?
By default, it probably isn't.
If you're the DBSA (database system administrator), you'll need to check that you've enabled 'drsoctcp' connections on the system, and configured a server alias to use that connection.
If you're not the DBSA, you'll need to chat with your DBSA to get the relevant information.
Assuming that you have DRDA connectivity enabled at the server side, you then need to ensure you have an appropriately configured ... DSN? Your client code needs to be able to connect to the server.
There is no reason I'm aware of why it cannot be done. However, I don't know exactly how to guide you step-by-step through any of the above.
You might need to seek assistance from IBM Technical Support.
You would help everyone if you clarified which version of Informix (the DBMS) you have, along with the version information for the platform where it is running (whether Windows or Unix, and the o/s version information) - and which version of the Data Server Provider you are using (and which variant of Windows you are using it on).
This exception is being thrown by the PostgreSQL 8.3.7 server to my application.
Does anyone know what this error means and what I can do about it?
ERROR: cached plan must not change result type
STATEMENT: select code,is_deprecated from country where code=$1
I figured out what was causing this error.
My application opened a database connection and prepared a SELECT statement for execution.
Meanwhile, another script was modifying the database table, changing the data type of one of the columns being returned in the above SELECT statement.
I resolved this by restarting the application after the database table was modified. This reset the database connection, allowing the prepared statement to execute without errors.
I'm adding this answer for anyone landing here by googling ERROR: cached plan must not change result type when trying to solve the problem in the context of a Java / JDBC application.
I was able to reliably reproduce the error by running schema upgrades (i.e. DDL statements) while my back-end app that used the DB was running. If the app was querying a table that had been changed by the schema upgrade (i.e. the app ran queries before and after the upgrade on a changed table) - the postgres driver would return this error because apparently it does caching of some schema details.
You can avoid the problem by configuring your pgjdbc driver with autosave=conservative. With this option, the driver will be able to flush whatever details it is caching and you shouldn't have to bounce your server or flush your connection pool or whatever workaround you may have come up with.
Reproduced on Postgres 9.6 (AWS RDS) and my initial testing seems to indicate the problem is completely resolved with this option.
Documentation: https://jdbc.postgresql.org/documentation/head/connect.html#connection-parameters
You can look at the pgjdbc Github issue 451 for more details and history of the issue.
JRuby ActiveRecords users see this: https://github.com/jruby/activerecord-jdbc-adapter/blob/master/lib/arjdbc/postgresql/connection_methods.rb#L60
Note on performance:
As per the reported performance issues in the above link - you should do some performance / load / soak testing of your application before switching this on blindly.
On doing performance testing on my own app running on an AWS RDS Postgres 10 instance, enabling the conservative setting does result in extra CPU usage on the database server. It wasn't much though, I could only even see the autosave functionality show up as using a measurable amount of CPU after I'd tuned every single query my load test was using and started pushing the load test hard.
For us, we were facing similar issue. Our application works on multiple schema. Whenever we were doing schema changes, this issue started occruding.
Setting up prepareThreshold=0 parameter inside JDBC parameter disables statement caching at database level. This solved it for us.
I got this error, I manually ran the failing select query and it fixed the error.