Results of 1 - 10 of about 52 for generate (0.002 sec.)
- Create Synthetic Data 13665
- DuckDB lets you quickly generate synthetic datasets by combining a few building blocks: functions and clauses that generate rows , functions that generate values to fill those rows, and extensions that generate whole benchmark datasets. Thi
...sh , md5 , sha256 the Faker Python package via the Python function API using cross products (Cartesian products) range and generate_series The range functions turn a start, stop, and step into a table of rows, which is the usual starting point for a synt...ROM range(1, 4) t(i); ┌───────┐ │ i │ │ int64 │ ├───────┤ │ 1 │ │ 2 │ │ 3 │ └───────┘ range excludes the stop value, while generate_series includes it. VALUES The VALUES clause generates rows from literal tuples, which is convenient for a small fixed set...eat_row repeat_row(varargs, num_rows) returns a fixed number of identical rows, which is useful as a scaffold to fill with generated values: FROM repeat_row('placeholder', 0, num_rows = 3); ┌─────────────┬─────────┐ │ column0 │ column1 │ │ varchar │ int3... - https://man.mtool.work/duckdb/2.0/guides/snippets/create_synthetic_data.html
- List Functions 10559
- Function Description list[index] Extracts a single list element using a (1-based) index . list[begin[:end][:step]] Extracts a sublist using slice conventions . Negative values are accepted. list1 && list2 Alias for list_has_any . list1 <->
...ns the element . filter(list, lambda(x)) Alias for list_filter . flatten(nested_list) Flattens a nested list by one level. generate_series(start[, stop][, step]) Creates a list of values between start and stop - the stop parameter is inclusive. grade_up(...s the cardinality of the result. See the unnest page for more details. unpivot_list(arg, ...) Identical to list_value, but generated as part of unpivot for better error messages. list[index] | Description | Extracts a single list element using a (1-based...scription | Flattens a nested list by one level. | | Example | flatten([[1, 2, 3], [4, 5]]) | | Result | [1, 2, 3, 4, 5] | generate_series(start[, stop][, step]) | Description | Creates a list of values between start and stop - the stop parameter is incl... - https://man.mtool.work/duckdb/2.0/sql/functions/list.html
- GROUPING SETS 10454
- GROUPING SETS , ROLLUP and CUBE can be used in the GROUP BY clause to perform a grouping over multiple dimensions within the same query. Note that this syntax is not compatible with GROUP BY ALL . Examples Compute the average income along t
...(city), (zip), () . This produces 2^n grouping sets. Identifying Grouping Sets with GROUPING_ID() The super-aggregate rows generated by GROUPING SETS , ROLLUP and CUBE can often be identified by NULL -values returned for the respective column in the grou...to distinguish whether the value in the resultset is a “real” NULL -value coming out of the data itself, or a NULL -value generated by the grouping construct. The GROUPING_ID() or GROUPING() function is designed to identify which groups generated the su...ns an integer value that identifies the combination of expressions that make up the group for which the super-aggregate is generated. At this point, an example might help. Consider the following query: WITH days AS ( SELECT year("generate_series") AS y,... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/grouping_sets.html
- VALUES Clause 10260
- The VALUES clause is used to specify a fixed number of rows. The VALUES clause can be used as a stand-alone statement, as part of the FROM clause, or as input to an INSERT INTO statement. Examples Generate two rows and directly return them:
...VALUES ('Amsterdam', 1), ('London', 2); Generate two rows as part of a FROM clause, and rename the columns: SELECT * FROM (VALUES ('Amsterdam', 1), ('London', 2)) cities(n...ame, id); Generate two rows and insert them into a table: INSERT INTO cities VALUES ('Amsterdam', 1), ('London', 2); Create a table directly... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/values.html
- Run Queries 10156
- Overview DuckDB-Wasm provides functions for querying data. Queries are run sequentially: First, create a connection by calling connect . Then, run queries by calling query to materialize the whole result, or send to fetch result chunks lazi
...const conn = await db.connect(); // Either materialize the query result await conn.query<{ v: arrow.Int }>(` SELECT * FROM generate_series(1, 100) t(v) `); // ..., or fetch the result chunks lazily for await (const batch of await conn.send<{ v: arrow.Int...}>(` SELECT * FROM generate_series(1, 100) t(v) `)) { // ... } // Close the connection to release memory await conn.close(); Prepared Statements Prepa...a new connection const conn = await db.connect(); // Prepare the query const stmt = await conn.prepare(`SELECT v + ? FROM generate_series(0, 10_000) t(v);`); // ... and run it with materialized results await stmt.query(234); // ... or as result chunks f... - https://man.mtool.work/duckdb/2.0/clients/wasm/query.html
- PostgreSQL Extension and the Secret Manager 9454
- User credentials and other PostgreSQL database connection details can be stored using the DuckDB Secrets Manager . The following syntax can be used to create a secret: CREATE SECRET ( TYPE postgres, HOST '127.0.0.1', PORT 5432, DATABASE pos
...greSQL databases running on RDS/Aurora services allow to use IAM authentication . In that case the authentication token is generated using AWS SDK and must be refreshed every 15 minutes. The postgres extension supports IAM authentication, when the passwo...rd is not specified in the secret, but instead one of the configured AWS Credential Providers is used to generate the password, that is refreshed by the postgres extension automatically. Connecting with IAM Authentication from Command L...When IAM authentication is performed using psql command line tool, the following are the AWS-recommended connection steps: Generate authentication token using aws CLI. Pass this token as a password connection option: bash export RDSHOST="database-1-insta... - https://man.mtool.work/duckdb/2.0/core_extensions/postgres/secrets.html
- CREATE SEQUENCE Statement 9050
- The CREATE SEQUENCE statement creates a new sequence number generator. Examples Generate an ascending sequence starting from 1: CREATE SEQUENCE serial; Generate sequence from a given start number: CREATE SEQUENCE serial START 101; Generate
...odd numbers using INCREMENT BY : CREATE SEQUENCE serial START WITH 1 INCREMENT BY 2; Generate a descending sequence starting from 99: CREATE SEQUENCE serial START WITH 99 INCREMENT BY -1 MAXVALUE 99; By default, cycl...ences can also be added using the ALTER TABLE statement . The following example adds an id column and fills it with values generated by the sequence: CREATE TABLE tbl (s VARCHAR); INSERT INTO tbl VALUES ('hello'), ('world'); CREATE SEQUENCE id_sequence S...or minvalue has been reached by an ascending or descending sequence respectively. If the limit is reached, the next number generated will be the minvalue or maxvalue , respectively. If NO CYCLE is specified, any calls to nextval after the sequence has re... - https://man.mtool.work/duckdb/2.0/sql/statements/create_sequence.html
- TPC-DS Extension 8752
- New In DuckDB 2.0, the dsdgen data generator was updated to match the TPC-DS version 4 tools. As a result, the generated data differs slightly from the data generated by DuckDB v1.x. See the related PR for more details. The tpcds extension
...he official extension repository. If you would like to install and load it manually, run: INSTALL AND LOAD tpcds; Usage To generate data for scale factor 1, use: CALL dsdgen(sf = 1); To run a query, e.g., query 8, use: PRAGMA tpcds(8); s_store_name sum(s...(); This function returns a table with columns query_nr , scale_factor and answer . Generating the Schema It's possible to generate the schema of TPC-DS without any data by setting the scale factor to 0: CALL dsdgen(sf = 0); Data Generator Parameters The...generator function dsdgen has the following parameters: Name Type Description catalog VARCHAR Target catalog keys BOOLEAN Generate primary and foreign keys overwrite BOOLEAN (Not used) schema VARCHAR Target schema sf DOUBLE Scale factor suffix VARCHAR A... - https://man.mtool.work/duckdb/2.0/core_extensions/tpcds.html
- Timestamp Functions 8752
- This section describes functions and operators for examining and manipulating TIMESTAMP values . See also the related TIMESTAMPTZ functions . Timestamp Operators The table below shows the available mathematical operators for TIMESTAMP types
...8:40 | Timestamp Table Functions The table below shows the available table functions for TIMESTAMP types. Name Description generate_series(timestamp, timestamp, interval) Generate a table of timestamps in the closed range, stepping by the interval. range...(timestamp, timestamp, interval) Generate a table of timestamps in the half open range, stepping by the interval. Infinite values are not allowed as table function...bounds. generate_series(timestamp, timestamp, interval) | Description | Generate a table of timestamps in the closed range, stepping by the... - https://man.mtool.work/duckdb/2.0/sql/functions/timestamp.html
- Loops 8543
- Loops can be used in sqllogictests when it is required to execute the same query many times but with slight modifications in constant values. For example, suppose we want to fire off 100 queries that check for the presence of the values 0..
...oops for inserting data using insert statements, this will considerably slow down the test cases. Instead, it is better to generate data using the built-in range and repeat functions. To create the table integers with the values [0, 1, ..., 98, 99] , run...ons, together with clever use of cross products and other expressions, many different types of datasets can be efficiently generated. The random() function can also be used to generate random data. An alternative option is to read data from an existing C...v/data/real using a COPY INTO statement or the read_csv_auto function. The TPC-H and TPC-DS extensions can also be used to generate synthetic data, using e.g. CALL dbgen(sf = 1) or CALL dsdgen(sf = 1) .... - https://man.mtool.work/duckdb/2.0/dev/sqllogictest/loops.html
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