Results of 1 - 10 of about 162 for Note (0.004 sec.)
- Text Functions 9768
- Text Functions and Operators This section describes functions and operators for examining and manipulating STRING values . Function Description string[index] Extracts a single character using a (1-based) index . string[begin:end] Extracts a
...eparator . NULL inputs are skipped. contains(string, search_string) Returns true if search_string is found within string . Note that collations are not supported. ends_with(string, search_string) Alias for suffix . format(format, ...) Formats a strin...lias for unbin . from_hex(value) Alias for unhex . greatest(arg1, ...) Returns the largest value in lexicographical order. Note that lowercase characters are considered larger than uppercase characters and collations are not supported. hash(value, ......) Returns a UBIGINT with the hash of the value . Note that this is not a cryptographic hash. hex(string) Converts the string to hexadecimal representation. ilike_escape(string,... - https://man.mtool.work/duckdb/2.0/sql/functions/text.html
- Multiple Python Threads 9585
- This page demonstrates how to simultaneously insert into and read from a DuckDB database across multiple Python threads. This could be useful in scenarios where new data is flowing in and an analysis should be periodically re-run. Note that
...in a single Python process (see the FAQ for details on DuckDB concurrency). Feel free to follow along in this Google Colab notebook . Setup First, import DuckDB and several modules from the Python standard library. Note: if using Pandas, add import p...hreads. Next, shuffle them so that they will be kicked off in a random order to simulate simultaneous writers and readers. Note that the threads have not yet been executed, only defined. write_thread_count = 50 read_thread_count = 5 threads = [] # Cr...Results Now, kick off all threads to run in parallel, then wait for all of them to finish before printing out the results. Note that the timestamps of readers and writers are interspersed as expected due to the randomization. # Kick off all threads i... - https://man.mtool.work/duckdb/2.0/guides/python/multiple_threads.html
- ALTER TABLE Statement 9013
- The ALTER TABLE statement changes the schema of an existing table in the catalog. Examples CREATE TABLE integers (i INTEGER, j INTEGER); Add a new column with name k to the table integers , it will be filled with the default value NULL : AL
...LTER TABLE integers RENAME TO integers_old; The RENAME TO clause renames an entire table, changing its name in the schema. Note that any views that rely on the table are not automatically updated. New As of DuckDB 2.0, ALTER TABLE ⟨view⟩ RENAME TO ⟨n...olumn within a table. Any constraints that rely on this name (e.g., CHECK constraints) are automatically updated. However, note that any views that rely on this column name are not automatically updated. ADD COLUMN To add a column of a table, use the...gers DROP COLUMN k; Or: ALTER TABLE integers DROP k; The DROP [COLUMN] clause can be used to remove a column from a table. Note that columns can only be removed if they do not have any indexes that rely on them. This includes any indexes created as p... - https://man.mtool.work/duckdb/2.0/sql/statements/alter_table.html
- Benchmarks 8647
- For several of the recommendations in our performance guide, we use microbenchmarks to back up our claims. For these benchmarks, we use datasets from the TPC-H benchmark and the LDBC Social Network Benchmark's BI workload . Datasets We use
...nDate column (4 GB .parquet file). The TPC datasets used in the benchmark are generated with the DuckDB tpch extension . A Note on Benchmarks Running fair benchmarks is difficult , especially when performing system-to-system comparison. When running...build ). If in doubt about your benchmark results, feel free to contact us at gabor@duckdb.org . Disclaimer on Benchmarks Note that the benchmark results presented in this guide do not constitute official TPC or LDBC benchmark results. Instead, they... - https://man.mtool.work/duckdb/2.0/guides/performance/benchmarks.html
- Timestamp with Time Zone Functions 8452
- This section describes functions and operators for examining and manipulating TIMESTAMP WITH TIME ZONE (or TIMESTAMPTZ ) values . See also the related TIMESTAMP functions . Time zone support is provided by the built-in ICU extension . In th
...:00+00:00[ + offset] when bucket_width is a number of months or coarser units, else 2000-01-03 00:00:00+00:00[ + offset] . Note that 2000-01-03 is a Monday. time_bucket(bucket_width, timestamptz[, origin]) Truncate timestamptz to a grid of width buck...ts to 2000-01-01 00:00:00+00:00 when bucket_width is a number of months or coarser units, else 2000-01-03 00:00:00+00:00 . Note that 2000-01-03 is a Monday. time_bucket(bucket_width, timestamptz[, timezone]) Truncate timestamptz to a grid of width bu...s a number of months or coarser units, else 2000-01-03 00:00:00 in the provided timezone . The default timezone is 'UTC' . Note that 2000-01-03 is a Monday. age(timestamptz, timestamptz) | Description | Subtract arguments, resulting in the time diffe... - https://man.mtool.work/duckdb/2.0/sql/functions/timestamptz.html
- Advanced Installation Methods 8086
- Downloading Extensions Directly from S3 Downloading an extension directly can be helpful when building a Lambda service or container that uses DuckDB. DuckDB extensions are stored in public S3 buckets, but the directory structure of those b
...Path The INSTALL command can be used with the path to a .duckdb_extension file: INSTALL 'path/to/httpfs.duckdb_extension'; Note that compressed .duckdb_extension.gz files need to be decompressed beforehand. It is also possible to specify remote paths.../to/httpfs.duckdb_extension'; This will skip any currently installed extensions and load the specified extension directly. Note that using remote paths for compressed files is currently not possible. Building and Installing Extensions from Source For... - https://man.mtool.work/duckdb/2.0/extensions/advanced_installation_methods.html
- Logging 7892
- 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
...enable_logging() without a level also captures warnings. Setting level = 'warning' excludes lower-severity INFO messages. Note Switching the CLI to a log storage other than shell_log_storage means that warnings are no longer printed to the console....To query logs in the CLI, switch to a queryable storage such as memory or file : CALL enable_logging(storage = 'memory'); Note that the duckdb_logs view is automatically updated to target the currently active log storage. This means that switching t...ging(storage_path = '/tmp'); -- denormalized: creates `/tmp/logs.csv` CALL enable_logging(storage_path = '/tmp/logs.csv'); Note that the difference between normalized and denormalized is typically hidden from users through the duckdb_logs function, w... - https://man.mtool.work/duckdb/2.0/operations_manual/logging/overview.html
- ATTACH and DETACH Statements 7892
- DuckDB allows attaching to and detaching from database files. Examples Attach the database file.db with the alias inferred from the name ( file ): ATTACH 'file.db'; Attach the database file.db with an explicit alias ( file_db ): ATTACH 'fil
....db' AS sqlite_db (TYPE sqlite); Attach the database file.db if inferred database alias file does not yet exist: ATTACH IF NOT EXISTS 'file.db'; Attach the database file.db if explicit database alias file_db does not yet exist: ATTACH IF NOT EXISTS '...file : USE file; ATTACH The ATTACH statement adds a new database file to the catalog that can be read from and written to. Note that attachment definitions are not persisted between sessions: when a new session is launched, you have to re-attach to a...'); To encrypt data, DuckDB can use either the built-in mbedtls library or the OpenSSL library from the httpfs extension . Note that the OpenSSL versions are much faster due to hardware acceleration, so make sure to load the httpfs for good encryptio... - https://man.mtool.work/duckdb/2.0/sql/statements/attach.html
- Startup & Shutdown 7709
- To use DuckDB, you must first initialize a duckdb_database handle using duckdb_open() . duckdb_open() takes as parameter the database file to read and write from. The special value NULL ( nullptr ) can be used to create an in-memory databas
...e . Note that for an in-memory database no data is persisted to disk (i.e., all data is lost when you exit the process). With the d...on used to create the database. out_error : If set and the function returns DuckDBError , this contains the error message. Note that the error message must be freed using duckdb_free . Return Value DuckDBSuccess on success or DuckDBError on failure....used to start up the database. out_error : If set and the function returns DuckDBError , this contains the error message. Note that the error message must be freed using duckdb_free . Return Value DuckDBSuccess on success or DuckDBError on failure.... - https://man.mtool.work/duckdb/2.0/clients/c/connect.html
- Secrets Manager 7709
- The Secrets manager provides a unified user interface for secrets across all backends that use them. Secrets can be scoped, so different storage prefixes can have different secrets, allowing for example to join data across organizations in
...a single query. Secrets can also be persisted, so that they do not need to be specified every time DuckDB is launched. Note Persistent secrets are stored in unencrypted binary format in the ~/.duckdb/stored_secrets directory. They are protected b...the following: CREATE SECRET my_secret ( TYPE s3, KEY_ID 'my_secret_key', SECRET 'my_secret_value', REGION 'my_region' ); Note that we implicitly use the default CONFIG secret provider here. Persistent Secrets In order to persist secrets between Duc...ecret_directory again when starting a new DuckDB instance before creating or using persistent secrets from that directory. Note that setting the value of the home_directory configuration option has no effect on the location of the secrets. Connection... - https://man.mtool.work/duckdb/2.0/configuration/secrets_manager.html
DuckDB 2.0 Documentation / man.mtool.work