Results of 1 - 10 of about 48 for Connections (0.002 sec.)
- PostgreSQL Extension Connection Pool 13313
- PostgreSQL server spawns a backend process for every incoming client connection. This model leads to the two following points with the postgres extension that can cause performance problems: opening a new connection is relatively expensive
...the number of the connections opened at the same time should not be too high To deal with these points the extensions uses an in-memory connection pool....With it a limited number of connections are kept open (and idle) after use and can be reused for subsequent queries. Parallel Scans Due to DuckDB's multithreaded...query processing, postgres extension can open multiple connections even for queries that performs a scan for a single PostgreSQL table. The number of parallel queries running for a single t... - https://man.mtool.work/duckdb/2.0/core_extensions/postgres/connection_pool.html
- PostgreSQL Extension Functions 12420
- postgres_clear_cache postgres_configure_pool postgres_execute postgres_hstore_get postgres_hstore_to_json postgres_query read_postgres_binary postgres_clear_cache postgres_clear_cache() -> TABLE Clears cached schema entries (like table name
...be specified and non-NULL when any other option is specified. acquire_mode ( VARCHAR , default: 'force' ): how to acquire connections from the pool: 'force' (always connect, ignore pool limit), 'wait' (block until available), 'try' (fail immediately if una...vailable) max_connections ( UBIGINT ): maximum number of connections that are allowed to be cached in a connection pool for each attached Postgres d...out_millis ( UBIGINT ): maximum number of milliseconds to wait when acquiring a connection from a pool where all available connections are already taken. enable_thread_local_cache ( BOOLEAN ): whether to enable the connection caching in thread-local cache.... - https://man.mtool.work/duckdb/2.0/core_extensions/postgres/functions.html
- Connect 10996
- Overview Every DuckDB feature reachable from Java starts with a Connection . This page covers the JDBC URL forms the driver accepts, how DuckDB and driver options are passed and which of them win, how connections come to share (or not share
...to open or attach a DuckLake , and how to reach a remote DuckDB server over Quack . Opening a Connection In JDBC, database connections are created through the standard java.sql.DriverManager class. On modern JVMs the driver registers itself with the DriverM...uckdb.DuckDBConnection; DuckDBConnection conn = (DuckDBConnection) DriverManager.getConnection("jdbc:duckdb:"); Additional connections can be created using the DriverManager . The DuckDBConnection#duplicate() method opens another connection to the same data...s opening a new connection on the same URL, because those instances are shared through the instance cache anyway. Multiple connections to the same instance are allowed, but they must all be opened with the same options. Options are applied when the instance... - https://man.mtool.work/duckdb/2.0/clients/java/connecting.html
- Multiple Connections 10102
- For tests whose purpose is to verify that the transactional management or versioning of data works correctly, it is generally necessary to use multiple connections. For example, if we want to verify that the creation of tables is correctly
...in con1 , then fire a query in con2 that checks that the table is not accessible yet until committed. We can use multiple connections in the sqllogictests using connection labels . The connection label can be optionally appended to any statement or query ....N TRANSACTION statement ok con1 CREATE TABLE integers (i INTEGER); statement error con2 SELECT * FROM integers; Concurrent Connections Using connection modifiers on the statement and queries will result in testing of multiple connections, but all the querie...s will still be run sequentially on a single thread. If we want to run code from multiple connections concurrently over multiple threads, we can use the concurrentloop construct. The queries in concurrentloop will be run con... - https://man.mtool.work/duckdb/2.0/dev/sqllogictest/multiple_connections.html
- Connect 9905
- Overview The Go client works through the standard database/sql types: a *sql.DB is a pool of connections to a DuckDB database. This page covers opening in-memory and file-backed databases, passing DuckDB configuration options, running initi
...to/foo.db") sql.Open() does not necessarily open a connection: it validates its arguments and returns a *sql.DB that opens connections lazily. Call db.Ping() to verify that the database is reachable. Data Source Names DuckDB configuration options are append...id. Thread Safety and Concurrency A *sql.DB is safe for concurrent use by multiple goroutines: it manages its own pool of connections and hands each in-flight query a connection of its own. A single *sql.Conn checked out with db.Conn() , and the DuckDB App...f native threads, sized by the threads option and shared across the pool. See the DuckDB concurrency documentation for how connections and threads interact. Connection Lifetime Temporary objects such as temporary tables are scoped to a connection. When code... - https://man.mtool.work/duckdb/2.0/clients/go/connecting.html
- Connect 9648
- Overview Every DuckDB feature reachable from Rust starts with a Connection . Opening in-memory and file-backed databases, configuring a database instance with Config , opening read-only, pooling connections across threads, the crate's threa
...uration page . Many of them can also be changed after connecting with a SET statement or the equivalent PRAGMA . Read-Only Connections A database file can be opened in read-only mode, which is useful when several processes read the same file at once. Set th...t cannot be shared between threads at the same time. The recommended pattern is one connection per thread. To open several connections to the same in-memory or file-backed database, use Connection::try_clone() , which opens a new connection to the already-o...to the same database DuckDB runs queries on its own pool of native threads, sized by the threads option and shared by all connections to a database instance. See the DuckDB concurrency documentation for how connections and threads interact. Connection Pool... - https://man.mtool.work/duckdb/2.0/clients/rust/connecting.html
- MySQL Extension 9057
- The mysql extension allows DuckDB to directly read and write data from/to a running MySQL instance. The data can be queried directly from the underlying MySQL database. Data can be loaded from MySQL tables into DuckDB tables, or vice versa.
...base=mysql' AS mysqldb (TYPE mysql); USE mysqldb; Warning Avoid including credentials, such as a password, directly in the connection string. If a connection error occurs, the full connection string, including your credentials, may appear in the resulting e...For better security, store credentials using secrets instead, as described in Configuring via Secrets . Configuration The connection string determines the parameters for how to connect to MySQL as a set of key=value pairs. Any options not provided are repl...E mysql, USER 'mysql', PASSWORD '' ); The information from the secret will be used when ATTACH is called. We can leave the connection string empty to use all of the information stored in the secret. ATTACH '' AS mysql_db (TYPE mysql); We can use the connect... - https://man.mtool.work/duckdb/2.0/core_extensions/mysql.html
- Reference 8618
- This page lists the functions, settings, and log types exposed by the quack extension . For a tour of the protocol, start with the Overview . Function Reference Server Management Function Description quack_serve(⟨listen_uri⟩, ...) Start a s
...sten_uri . quack_server_list() List the servers running in this instance: listen URI and URL, host, port, number of active connections, and additional info (IPv6, SSL). quack_active_connections() List the client connections of the servers running in this in...emory_limit . FETCH counts serialized payload bytes, INSERT counts decoded chunk allocations. 0 disables the limit. Server Connections Setting Type Default Description quack_server_max_connections UBIGINT 1024 Maximum number of concurrent connections the se...rver accepts. Beyond this, new connections are refused. quack_server_keep_alive_timeout UBIGINT 300 Seconds an idle keep-alive connection is kept open by the server.... - https://man.mtool.work/duckdb/2.0/quack/reference.html
- Tuning Workloads 8360
- DuckDB aims to perform well out of the box, so most workloads do not require any tuning. When tuning is worthwhile, there is no single configuration or magic number that is optimal for every workload: the right settings depend on what you a
.../O and minimizing IO Querying remote files Running many small queries Reusing a single connection Best practices for using connections The rest of this page covers each of these areas in detail. See the configuration reference for the full list of available...he remote file as configured by the validate_external_file_cache setting. Warning The external file cache is shared by all connections of a database instance. Only set this option if every connection may read the cached files, e.g., because all connections...use the same credentials. Best Practices for Using Connections DuckDB will perform best when reusing the same database connection many times. Disconnecting and reconnecting on every que... - https://man.mtool.work/duckdb/2.0/guides/performance/how_to_tune_workloads.html
- Java (JDBC) Client 8027
- Installation To use the DuckDB Java (JDBC) client, visit the Java installation page . The latest stable version of the DuckDB Java (JDBC) client is 2.0.0. The DuckDB Java (JDBC) client lets Java applications query DuckDB through the standar
...information about our extensions to the JDBC specification, or the Arrow Methods . Opening a Connection In JDBC, database connections are created through the standard java.sql.DriverManager class, using the jdbc:duckdb: JDBC URL prefix: import java.sql.Con...ent(); ResultSet rs = stmt.executeQuery("SELECT 42")) { rs.next(); System.out.println(rs.getInt(1)); // prints 42 } Define Connections covers the connection lifecycle in full: the URL forms the driver accepts, DuckDB and driver configuration options, read-o...nly mode, instance caching, threading, and shutdown. Further Reading Define Connections — the JDBC URL forms, configuration options, instance caching, threading, and connection shutdown. Connect to a DuckLake —... - https://man.mtool.work/duckdb/2.0/clients/java/overview.html
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