Results of 1 - 10 of about 36 for Control (0.002 sec.)
- Concurrency 15975
- Handling Concurrency Single Process In in-process mode, DuckDB has two configurable options for concurrency: Read-write mode: one process can both read and write to the database. Read-only mode: multiple processes can read from the database
...When using read-write mode, DuckDB supports multiple writer threads using a combination of MVCC (Multi-Version Concurrency Control) and optimistic concurrency control (see Concurrency within a Single Process ), but all within that single writer process....tiple threads can also simultaneously update separate tables or separate subsets of the same table. Optimistic concurrency control comes into play when two threads attempt to edit (update or delete) the same row at the same time. In that situation, the...n the same database. DuckLake 1.1 , intended for production use, was released alongside DuckDB 2.0. Optimistic Concurrency Control DuckDB uses optimistic concurrency control , an approach generally considered to be the best fit for read-intensive analyt... - https://man.mtool.work/duckdb/2.0/connect/concurrency.html
- Securing DuckDB 10301
- DuckDB is a powerful analytical database engine. It can read and write files, access the network, load extensions, and use system resources. Like any powerful tool, these capabilities require appropriate configuration when working with sens
...non-SQL APIs: File paths: Functions like duckdb.read_csv(path) or duckdb.read_parquet(path) accept file paths. An attacker-controlled path could read sensitive files (e.g., /etc/passwd ) or access remote URLs. Table and column names: While these are typ...ents. Autoloading DuckDB can automatically load core extensions when certain SQL statements require them. To maintain full control over which extensions are loaded, you can disable autoloading: SET autoload_known_extensions = false; SET autoinstall_know...s or files using the allowed_directories and allowed_paths options (respectively). These options allow fine-grained access control for the file system. For example, you can set DuckDB to only use the /tmp directory. SET allowed_directories = ['/tmp']; S... - https://man.mtool.work/duckdb/2.0/operations_manual/securing_duckdb/overview.htm...
- Profile and Monitor 9715
- Overview The JDBC driver exposes several ways to observe a running or completed query: cancelling and timing out queries, polling query progress, retrieving profiling output, and emitting memory-usage events through Java Flight Recorder . T
...r can emit Java Flight Recorder events describing DuckDB's internal memory usage, so that any JFR-aware tool — JDK Mission Control, the jfr command line tool, continuous profilers — can ingest DuckDB memory metrics alongside the rest of the JVM signal....mpty string Events emitted, tagged with the given value. The JDBC property is only an enable and label switch. It does not control whether JFR is recording or the sampling period; those are governed by the JFR recording settings. Controlling the Period...jfr are loaded. No additional JVM flags are required. Inspecting a Recording Inspect a captured recording with JDK Mission Control or the jfr command line tool bundled with the JDK: jfr summary app.jfr | grep duckdb.MemoryUsage jfr print --events duckdb... - https://man.mtool.work/duckdb/2.0/clients/java/profiling.html
- Gitignore for DuckDB 8938
- If you work in a Git repository, you may want to configure your Gitignore to disable tracking files created by DuckDB . These potentially include the DuckDB database, write-ahead log, and temporary files. Sample Gitignore Files In the follo
...Temporary Files but Keep Database This configuration is useful if you would like to keep the database file in the version control system: *.wal *.tmp/ Ignore Database and Temporary Files If you would like to ignore both the database and the temporary f... - https://man.mtool.work/duckdb/2.0/operations_manual/footprint_of_duckdb/gitignor...
- Using fsspec Filesystems 8732
- DuckDB support for fsspec filesystems allows querying data in filesystems that DuckDB's httpfs extension does not support. fsspec has a large number of inbuilt filesystems , and there are also many external implementations . This capability
...ttpfs extension. It is also worth noting that as they are third-party libraries, they may contain bugs that are beyond our control.... - https://man.mtool.work/duckdb/2.0/guides/python/filesystems.html
- Logging 8352
- DuckDB implements a logging mechanism that provides users with detailed information about events such as query execution, performance metrics and system events. Warning Logs may contain sensitive information, including secrets and credentia
...ging(); To clear the current log, run CALL truncate_duckdb_logs(); Log Level DuckDB supports different logging levels that control the verbosity of the logs: FATAL : Only logs fatal errors ERROR : Logs error messages WARNING : Logs warnings and errors I...orage') . Log Types In DuckDB, log messages can have an associated log type. Log types allow two main things: Fine-grained control over log message generation Support for structured logging Logging-Specific Types To log only messages of a specific type:...LL enable_logging('HTTP') together with duckdb_logs_parsed('HTTP') ) instead. The redact_http_logs setting (default true ) controls whether HTTP header values are redacted in the logs. To enable multiple log types, simply pass: CALL enable_logging(['HTT... - https://man.mtool.work/duckdb/2.0/operations_manual/logging/overview.html
- Unnesting 8352
- Unnesting is an operation that decomposes values of a composite types into its components. Values of the LIST and STRUCT type may be unnested using the unnest() function . Unnesting turns a LIST -typed value into a table column: each list-e
...st – mandatory – argument to the unnest() function. The unnest() function has a number of optional additional arguments to control the behavior for recursive unnesting . The unnest function can be called in the SELECT -clause as if it is a scalar functi...ditional parameters such as max_depth and keep_parent_names are effectively ignored max_depth : UINT32 , default: 1 . This controls how many levels of recursion should at most be applied. Values greater than 1 imply recursion, and in such cases recursiv...convention of the original data. The parameter can also be used in conjunction with the max_depth parameter, allowing more control and enabling more precise management of nested structures.... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/unnest.html
- EXPLAIN: Inspect Query Plans 8146
- EXPLAIN SELECT * FROM tbl; The EXPLAIN statement displays the physical plan, i.e., the query plan that will get executed, and is enabled by prepending the query with EXPLAIN . The physical plan is a tree of operators that are executed in a
...., memory.main.exams ). Additional Explain Settings The EXPLAIN statement supports additional settings that can be used to control the output. The following settings are available: The default setting. Only shows the physical plan. SET explain_output =... - https://man.mtool.work/duckdb/2.0/guides/meta/explain.html
- Tuning Workloads 8146
- 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
...the content of the external file cache, run: FROM duckdb_external_file_cache(); The external file cache follows the Cache-Control headers of HTTP responses: data from a response marked no-store , no-cache or private , or from a response that is already...not reused. Object stores often send such headers on authenticated reads. For example, Google Cloud Storage returns Cache-Control: private, max-age=0 for every read of a non-public object, so by default, these files are read from the object store again... - https://man.mtool.work/duckdb/2.0/guides/performance/how_to_tune_workloads.html
- Security 8146
- This page covers Quack's security posture end to end: what the server exposes, what stays local, the role of a TLS-terminating reverse proxy, and the authentication / authorization callbacks the server runs on every connection and every que
...an authorization function that inspects the parsed statement type rather than the raw query text. Example: Per-User Access Control List To implement per-user access control list (ACL), create a custom authentication hook that records sid → user pairs so... - https://man.mtool.work/duckdb/2.0/quack/security.html
DuckDB 2.0 Documentation / man.mtool.work