I am using DBeaver to connect to my MS SQL database hosted in local. I try to export my tables as CSV files. In the case where the query is rather big (40k rows which takes a couple of minutes) the export gets stopped with the message
"SQL Error: The connection is closed".
I kept the default parameters for dbeaver database connection, and my SQL server timeout is the default one (10 minutes, which is more than it takes to trigger the error)
Any idea where it might come from?
You know, the value of binary is extremely large and weight. So that takes much time to transfer via the network. That's the reason why you're getting error. In my opinion,
You should split your query into multiple time to fetch data (How about 1k records in each time).
Just get the exactly items that you need (where condition or the columns that you need instead of all)
Every database driver allows to configure the connectTimeout, a parameter that declares for how long the client (dbeaver) will wait before deciding something went wrong.
You can change this parameter right-clicking on the name of the server, choosing Edit Connection, then clicking on the Driver properties tab and searching for the connectTimeoutparameter (or something equivalent). Increase the value you found there.
I had this problem with PostgreSQL 13, found a connectTimeout = 20ms and increased it to 200ms to overcome the issue.
An old MySQL driver showed a connectTimeout = 20000, most probably in nanoseconds.
Related
We recently upgraded our SQL server to 2016 and I turned on QueryStore to do the analysis that it provides. I'm encountering a problem where, even if the time period of the report is Last hour, it will generate a message that says "Couldn't connect to database" even when running it on the database server itself. Sometimes if I keep refreshing the report it will eventually display some data, but it's intermittent at best. I'm running SSMS 17.5 on a sql server 2016 server.
We are having a somewhat similar issue with another program that connects to the database where it will sometimes not be able to connect, but every time I run my queries in SSMS, run reports in SSRS, or even use activity monitor, I never see any connection drops, so I'm not sure if it is related.
Thank you in advance for any help!
I find it works fine with the statistic set to Avg, StdDev, or Total. Max and Min give the error.
I found this happens when the query store runs out of space and gets into cleanup mode.
In database properties in SSMS try playing around with Query Store settings: for how many days it stores the query stats and does it get into "size cleanup" mode. More info on how to keep it adjusted: https://learn.microsoft.com/en-us/sql/relational-databases/performance/best-practice-with-the-query-store?view=sql-server-ver15#Configure
I have a postgres table containing nearly 700,000 records, I import that table into MS access (via an ODBC data source) and end up with only 250,000 records.
I start with an empty MS access database (520 kbytes). Select (external data)/(New data source)/(from other sources)/(ODBC database)/(Import the source data)/(Machine data source) I pick my ODBC postgres database, and select the table I want, wait for 30 seconds, then I get a message box saying all objects have been successfully imported followed by being asked if I want to save the import steps.
There are no error messages, but the number of rows in my MS access version of the table is around 250,000.
Other info...
I'm using MS office 365 version 1710
I'm using postgres 9.5.7
I'm using the PostgrSQL ANSI ODBC driver (not sure which version)
There are no signs of any error messages (or warnings).
After the import the Access database is still only 375 Mbytes, well short of the 2 Gbyte limit.
I've checked the 'ODBC data sources' app to check how the postgres ODBC link is configured, there's no obvious problem with it.
The final message that MS access gives me after the import includes 'all objects imported without errors'
There is no obvious difference between the records that are getting through and those that aren't.
Why am I losing records, and what can I do to cure it?
Thanks
If you attempt to "slurp" all records from the database at one time, the ODBC driver will stop fetching at some point and just return what it has without warning. It's annoying. As far as I know this has nothing to do with the 32-bit limit.
The way to solve this is to not fetch all records at once, but use the declare/fetch option on the driver. You can do this permanently on the ODBC settings by going to your ODBC properties, selecting "Datasource" and then on "Page 2" checking the "Use Declare/Fetch" and setting your cache (# of rows) size. I recommend a number somewhere between 5,000 and 50,000. Each batch represents a hit to the database, so you want it to be reasonably large to begin with.
From all practical purposes, the use of declare/fetch will be totally transparent to your application. You won't even notice. You will on the database admin side, but if your fetch size is sufficiently large, it won't be an issue.
You can also do one-time edits to your connection string from your particular query. You would add the following to make this work:
UseDeclareFetch=1;Fetch=25000;
I connect from ms access (frontend) to MS SQL server (database) using ODBC and file datasource. I've created MS Access pass-trough query collecting data from SQL Server (directly calls MS SQL Server function returning table).
When I run this query in MS SQL Management console, it runs about 1s. When I run it from MS Access, using ODBC connection string, the same query runs about 5 minutes (!!). But when I clear connection string from query properties, it runs between 1 and 2 seconds (so acceptable).
Other queries and linked tables using the same connection string works correctly (so the string is rather OK)
Why the hell this one makes problem? Any idea hat to check?
I know this is an old post but... I've been googling to no avail so I wanted to put this out there...
I have a drill down SP that returns.... 200 rows max
The MS Access app uses ALL pass through queries to Azure. All work great except for this one. In SSMS it comes back almost instantly. ODBC string is the same on ALL Queries so the connection is fine.
After setting the max rows property to 1000, the form came back almost instantly. Cleared the property and it went back to slow...
This property definitely made the difference for me. Setting it to a number that is well beyond the upper limit really got this working as it should be.
hth,
..bob
I use windows authentication (trust) only.
"clear" means to remove all except "ODBC;" phrase. When I leave this notice in query properties, the Access asks for DSN, I select one, and then I got the results after 2 sek.
But When I put full connection string
ODBC;Description=My Database;DRIVER=SQL Server;SERVER=MYSERVER;APP=2007 Microsoft Office system;DATABASE=MYDB_Prod;LANGUAGE=polski;Trusted_Connection=Yes
The query I call is:
SELECT * FROM dbo.fn_MyFunction()
Function fn_MyFunction() is table valued one, returns two rows and about 50 columns ( suspected large number of column might be the issue, because other queries have less one), and it is used in access report (that's why I use pass through query - the same happens when I test with MS SQL server view linked to MS Access tablle via odbc)
The same connection string works well with other queries
It seems I found solution (or workaround rather?) I've made the tests using VPN over internet link. When I move to office - it works well and return almost immediatelly with the string I wrote above.
It is strange for me that link type have such impact: other queries works well on both (LAN an VPN over internet), but this one - only on LAN ( works over internet too but with unacceptable performance). I could understand if all works slow.. by why this one? Any idea?
I have a Symfony command line task that has a habit of dropping the mysql connection.
Its a data import task. Which fetches data from multiple connections. Its not one big query but a few smaller ones.
It seems to drop the connection the first time it is ran. About half way through the script. However the second time its ran (from the beginning) it always completes the task.
Its not timing out on the query as the error response I get is that the connection has been dropped and it runs ok on its own. So im thinking that its some kind of timeout issue that is avoided when its ran the second time due to query caching speeding up the script.
So my question is how do I refresh the database connection?
[Doctrine\DBAL\DBALException]
SQLSTATE[HY000]: General error: 2013 Lost connection to MySQL server during query
A different approach is to check if Doctrine is still connected to the MySQL server through the ping() method in the connection. If the connection is lost, close the active connection since it is not really closed yet and start a new one.
if(FALSE == $em->getConnection()->ping()){
$em->getConnection()->close();
$em->getConnection()->connect();
}
I guess you mean to connect to the database if the connection is lost for some reason. Given an EntityManager, you can do it the following way:
$success = $_em->getConnection()->connect();
With getConnection, you are retrieving the connection object doctrine uses (Doctrine\DBAL\Connection), which exposes the connect method.
You can call connect anytime, as it checks wether a connection is already established. If this is the case, it returns false.
There is also a isConnected method to check wether a connection is established. You could use that to see where exactly the connection is dropping to get a clearer picture of what is happening.
I am running Access 2010 FE and SQL Server 2005 BE.
I can execute pass through queries to my SQL Server succesfully by using DSNless connections.
During my testing phase sometimes I need to restore my database to get back to my original records so I can rerun my pass through queries. What I have found is when I run a pass through query, it creates an active connection on my SQL Server. I see the connection via the SQL Server Management Console under the MANAGEMENT | SQL Server Logs | Activity Monitor, select view processes. There I can see which process ID is being used and who is using it when I run my pass through query.
Now the only way for me to restore my database is to KILL the PROCESS e.g. Active connection
Now when I have my restored database in place and re-run the pass through query, I receive a ODBC -- Call Failed message box. I have attempted to run a procedure to refresh my querydefs but to no avail, I will still get the ODBC-- Call Failed message box when I click on those objects.
Now there are two options on how to fix this problem, which in either case I find not USER Friendly.
Restart my Access Application
Wait approx 5-10 minutes to rerun the Pass Through Query
I created a function to trap my ODBC Errors and this is what appears:
ODBC Error Number: 0
Error Description: [Microsoft][ODBC SQL Server Driver]Communication link failure
ODBC Error Number: 3146
Error Description: ODBC--call failed.
So if for some reason, I need to restart my SQL server or kill a process (Active Connection) on my SQL server while the Access Application is currently connected via ODBC, the objects created via ODBC will not perform properly till I execute the 2 workaround solutions as stated above.
Can anyone shed some advice on a solution? I appreciate any insight.
I asked a similar question some time ago, and never got a satisfactory answer. My original question is here: Force SET IDENTITY_INSERT to take effect faster from MS Access
There is a registry setting documented here for ACE that controls the timeout behavior:
ConnectionTimeout: The number of seconds a cached connection can remain idle before timing out. The default is 600 (values are of type REG_DWORD).
So as a third workaround (in addition to the two you already listed) you can change that registry setting to a shorter timeout (like 10 seconds). This is the approach I took in my answer. One caveat is that shortening the timeout may cause performance or other issues. Your mileage may vary.
See my full answer to the original question for more info.