Results of 1 - 10 of about 17 for Tuples (0.003 sec.)
- Struct Data Type 12414
- Conceptually, a STRUCT column contains an ordered list of columns called “entries”. The entries are referenced by name using strings. This document refers to those entry names as keys. Each row in the STRUCT column must have the same keys.
...at column, part3 is a property of that column Any extra parts (e.g., .part4.part5 , etc.) are always treated as properties Tuples New The TUPLE type was introduced in DuckDB 2.0. In earlier versions, unnamed structs were STRUCT values with empty keys....A TUPLE is a struct whose entries have no names. Its entries are referenced by their (1-based) position. Tuples are created using the row function or, if there are at least two expressions, using parentheses: SELECT row(x, x + 1, y) A...') AS t); ┌───────┬─────────┐ │ first │ second │ │ int32 │ varchar │ ├───────┼─────────┤ │ 42 │ duck │ └───────┴─────────┘ Tuples in Tables Tuples can be stored in tables, either by declaring a TUPLE column or by using CREATE TABLE ... AS : CREATE TABL... - https://man.mtool.work/duckdb/2.0/sql/data_types/struct.html
- Boolean Type 11966
- Name Aliases Description BOOLEAN BOOL Logical Boolean ( true / false ) The BOOLEAN type represents a statement of truth (“true” or “false”). In SQL, the BOOLEAN field can also have a third state “unknown” which is represented by the SQL NUL
...10 results in a Boolean value. Boolean values can be used in the WHERE and HAVING clauses of a SQL statement to filter out tuples from the result. In this case, tuples for which the predicate evaluates to true will pass the filter, and tuples for which... - https://man.mtool.work/duckdb/2.0/sql/data_types/boolean.html
- Data Chunks 11362
- Data chunks represent a horizontal slice of a table. They hold a number of vectors , that can each hold up to the VECTOR_SIZE rows. The vector size can be obtained through the duckdb_vector_size function and is configurable, but is usually
...k : The data chunk to get the data from Return Value The vector duckdb_data_chunk_get_size Retrieves the current number of tuples in a data chunk. Syntax idx_t duckdb_data_chunk_get_size ( duckdb_data_chunk chunk ); Parameters chunk : The data chunk to...get the data from Return Value The number of tuples in the data chunk duckdb_data_chunk_set_size Sets the current number of tuples in a data chunk. Syntax void duckdb_data_ch...t_size ( duckdb_data_chunk chunk , idx_t size ); Parameters chunk : The data chunk to set the size in size : The number of tuples in the data chunk... - https://man.mtool.work/duckdb/2.0/clients/c/data_chunk.html
- IN Operator 9707
- The IN operator checks containment of the left expression inside the collection on the right hand side (RHS). Supported collections on the RHS are tuples, lists, and maps, as well as subqueries that return a single column. The single-column
...restriction applies only to subqueries; tuples, lists, and maps may themselves contain composite values. IN (val1, val2, ...) (Tuple) The IN operator on a tuple (val1, v... - https://man.mtool.work/duckdb/2.0/sql/expressions/in.html
- GROUP BY Clause 9707
- The GROUP BY clause specifies which grouping columns should be used to perform any aggregations in the SELECT clause. If the GROUP BY clause is specified, the query is always an aggregate query, even if no aggregations are present in the SE
...LECT clause. When a GROUP BY clause is specified, all tuples that have matching data in the grouping columns (i.e., all tuples that belong to the same group) will be combined. The val... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/groupby.html
- Samples 8500
- Samples are used to randomly select a subset of a dataset. Examples Select a sample of exactly 5 rows from tbl using reservoir sampling: SELECT * FROM tbl USING SAMPLE 5; Select a sample of approximately 10% of the table using system sampli
...d for use with percentages. That is because reservoir sampling needs to materialize the entire sample and randomly replace tuples within the materialized sample. The larger the sample size, the higher the performance hit incurred by this process. Reser...included with a chance equal to the specified percentage. As a result, bernoulli sampling can return a different number of tuples even if the same percentage is specified. The expected number of rows is equal to the specified percentage of the table, b...pling percentage. This is a form of cluster sampling. System sampling is more efficient than bernoulli sampling, as no per-tuple selections have to be performed. The expected number of rows is still equal to the specified percentage of the table, but t... - https://man.mtool.work/duckdb/2.0/sql/samples.html
- Unnesting 8362
- 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
...d) ordinal position of the member, prefixed by element . The dot-star ( ⟨struct⟩.* ) shorthand syntax is not available for tuples: tuples can only be unnested using the unnest() function. Calling unnest() The LIST or STRUCT value that is to be unnested... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/unnest.html
- Complete API 7897
- This page contains the reference for DuckDB's C API. The reference contains several deprecation notices. These concern methods whose long-term availability is not guaranteed as they may be removed in the future. That said, DuckDB's develope
...ptr : The memory region to de-allocate. duckdb_vector_size The internal vector size used by DuckDB. This is the amount of tuples that will fit into a data chunk created by duckdb_create_data_chunk . Return Value The vector size. Syntax idx_t duckdb_ve...k : The data chunk to get the data from Return Value The vector duckdb_data_chunk_get_size Retrieves the current number of tuples in a data chunk. Syntax idx_t duckdb_data_chunk_get_size ( duckdb_data_chunk chunk ); Parameters chunk : The data chunk to...get the data from Return Value The number of tuples in the data chunk duckdb_data_chunk_set_size Sets the current number of tuples in a data chunk. Syntax void duckdb_data_ch... - https://man.mtool.work/duckdb/2.0/clients/c/api.html
- Execution Format 7759
- Vector is the container format used to store in-memory data during execution. DataChunk is a collection of Vectors, used for instance to represent a column list in a PhysicalProjection operator. Data Flow DuckDB uses a vectorized query exec
...ze. This fixed size is commonly referred to in the code as STANDARD_VECTOR_SIZE . The default STANDARD_VECTOR_SIZE is 2048 tuples. Vector Format Vectors logically represent arrays that contain data of a single type. DuckDB supports different vector for... - https://man.mtool.work/duckdb/2.0/internals/vector.html
- SELECT Statement 7759
- The SELECT statement retrieves rows from the database. Examples Select all columns from the table tbl : SELECT * FROM tbl; Select the rows from tbl : SELECT j FROM tbl WHERE i = 3; Perform an aggregate grouped by the column i : SELECT i, su
...sions that transform the output, as well as aggregates and window functions. The DISTINCT keyword ensures that only unique tuples are returned. Column names are case-insensitive. See the Rules for Case Sensitivity for more details. FROM Clause The FROM... - https://man.mtool.work/duckdb/2.0/sql/statements/select.html
DuckDB 2.0 Documentation / man.mtool.work