I'm new to snowflake and I am curious to know How many simultaneous connections can be open to snowflake through JDBC with same credentials? If there is limit to the connections with different credentials?
There is no such limit on how many connections you can start from JDBC.
However is there any specific use case, that you need to start multiple connections?
A single connection can be used to query the DB and you can use multiple statements in the same query.
https://docs.snowflake.com/en/user-guide/jdbc-using.html#sending-multiple-statements-handling-results
Related
Can I issue multiple queries in the same connection or do I need to issue them 1 query per connection ?
All database API's that I've seen support multiple queries in the same connection. In fact, it's a good practice to keep your connection around if you are likely to have more queries soon.
I want to use single database connection from multiple threads to read (or to execute only select statements) in MS SQL Server in simultaneously. Is it possible to execute all these select statements in simultaneously from different threads.
I m using MS SQL Server from C++ in Linux environment. I need to create Database connection pools for reading and writing separately. So i want to know is there a possibility of sharing a same connection between threads to read only.
The select statements may return multiple rows (more than one row or result set). Will this be a problem?
Yes there will be a problem. Only one command can be executed at a time.
But you'll be fine using multiple connections, connection pooling works great for SQL server.
Don't use the same connection across threads. Only one command can be executed per connection. Create a connection for each thread. I'd suggest making a helper class to make this easier for you.
I want to use single database connection from multiple threads to read (or to execute only select
statements) in MS SQL Server in simultaneously
You should start reading the documentation and not start having funny ideas that whas you want matters here.
Yes, you CAN do that (MARS is the topic- read it up) but one connection can alwayso nly have one transaction context so it isa good approach to ahvem ultiple selects in one transaction (insert, couple of upserts etc.) but bad as a generic approach for progrmaming database connections.
Follow the recipes which mean iopen a conenction when you need it, close it when done and dont be afraid to run mtultiple connections.
If you worry about multi process in SQL Server, must think of two option.
Parallelism settings
AlwaysOn setup
The first one helps you by executing a single query with more than one cpu logical core; while the second one helps you to have a load balance, when you have concurrent connections.
I am developing an application that will be used by many users in the same time (on a network). The application will use SQL Server.
I want to know if it's good to use transactions for different queries that I have. If one user start a transaction at a time and another user starts one more, will the server know whom is a random transaction? Multiple transactions at a time are supported by one single server?
Yes, SQLServer supports multiple simultaneous transactions. There would be no point in having transactions if you could not run more than one at a time.
I have an windows desktop application running with with SQL Server CE, now my customer request to have a network version for this application, my question is can SQL Server CE support multiple connection and transaction at a time? Thanks
It does support multiple connections from the same computer according to this technet document:
http://technet.microsoft.com/en-us/library/bb380177%28SQL.90%29.aspx
The relevant section of the document:
SSCE Concurrency
SSCE allows multiple connections to the same database (.sdf file) from the same application or even multiple applications on the same computer. This gives you more freedom to structure your application as needed, such as allowing the user to continue to interact with data while performing synchronization with a back-end database, or to have multiple applications on the same machine share an SSCE data store. Transactional concurrency locks are made by the database engine to prevent concurrent connections from accessing the same records at the same time. The technical limit on concurrent connections for a single database is 256, but 70-80 is a better practical limit from a performance perspective.
No, for this requirement, you can use the free SQL Server Express
We have an application that uses NHibernate to connect to our database on SQL Server.We use connection pooling and session per request approach to execute our queries over SQL Server.
We used SQL Server Activity Monitor to monitor connections count and noticed there was 25-30 connections involved whenever a user logged in to system.
So here's my question to ask : can large number of connections to SQL Server leads to performance issues?
Each connection to SQL Server requires the allocation of certain amount of memory and so there is a performance consideration in this regard.
In the scheme of things however, 20-30 connections is a very small number.
Have you validated that all connections belong to your application? The reason I ask is because SQL Server itself will establish and maintain a certain number of connections/sessions as part of the servers overall operation.
Some usefull DMV's for you to monitor:
select * from sys.dm_exec_connections
select * from sys.dm_exec_sessions
Session ID's above 51 are from outside of SQL Server so to speak, i.e. user sessions.
Further to comments:
SQL Server 2005 can support up to 32,767 connections. To check your capacity execute:
select ##MAX_CONNECTIONS
If connection pooling is being used then connections will remain open and in a sleep state until required for processing requests. Alternatively, perhaps the application is not closing connections when requests have finished processing.
I can only comment from a SQL Server perspective as I am not familiar with the mechanics of NHibernate.