Results of 1 - 10 of about 35 for keys (0.003 sec.)
- Map Type – DuckDB 12952
- This page is for DuckDB 1.3, which is outdated. Switch to the current version . Search Shortcut cmd + k | ctrl + k Installation Documentation Getting Started Connect Overview Concurrency Data Import Overview Data Sources CSV Files Overview
...s are similar to STRUCT s in that they are an ordered list of key-value pairs. However, MAP s do not need to have the same keys present for each row, and thus are suitable for use cases where the schema is unknown beforehand or varies per row. MAP s...must have a single type for all keys, and a single type for all values. Keys and values can be any type, and the type of the keys does not need to match the ty...pe of the values (e.g., a MAP of VARCHAR to INT is valid). MAP s may not have duplicate keys. MAP s return NULL if a key is not found rather than throwing an error as structs do. In contrast, STRUCT s must have stri... - https://man.mtool.work/duckdb/1.3/sql/data_types/map.html
- Map Functions – DuckDB 12698
- This page is for DuckDB 1.3, which is outdated. Switch to the current version . Search Shortcut cmd + k | ctrl + k Installation Documentation Getting Started Connect Overview Concurrency Data Import Overview Data Sources CSV Files Overview
...the key is not contained in the map. The type of the key provided in the second parameter must match the type of the map's keys; else, an error is thrown. map_concat(maps...) Returns a map created from merging the input maps . On key collision the va...the key is not contained in the map. The type of the key provided in the second parameter must match the type of the map's keys; else, an error is thrown. map_extract_value(map, key) Returns the value for a given key or NULL if the key is not contain...ed in the map. The type of the key provided in the second parameter must match the type of the map's keys; else, an error is thrown. map_from_entries(STRUCT(k, v)[]) Returns a map created from the entries of the array. map_keys(... - https://man.mtool.work/duckdb/1.3/sql/functions/map.html
- Struct Data Type – DuckDB 9993
- This page is for DuckDB 1.3, which is outdated. Switch to the current version . Search Shortcut cmd + k | ctrl + k Installation Documentation Getting Started Connect Overview Concurrency Data Import Overview Data Sources CSV Files Overview
...f 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. The names of the struct entries are part of the schema . Each row...T s and LIST s. STRUCT s are similar to PostgreSQL's ROW type. The key difference is that DuckDB STRUCT s require the same keys in each row of a STRUCT column. This allows DuckDB to provide significantly improved performance by fully utilizing its ve...able, or using the row function. Create a struct using the struct_pack function. Note the lack of single quotes around the keys and the use of the := operator: SELECT struct_pack ( key1 : = 'value1' , key2 : = 42 ) AS s ; Create a struct using the ar... - https://man.mtool.work/duckdb/1.3/sql/data_types/struct.html
- CREATE TABLE Statement – DuckDB 9993
- This page is for DuckDB 1.3, which is outdated. Switch to the current version . Search Shortcut cmd + k | ctrl + k Installation Documentation Getting Started Connect Overview Concurrency Data Import Overview Data Sources CSV Files Overview
...: CREATE TABLE t1 AS FROM t2 LIMIT 0 ; It is not possible to create tables using CTAS statements with constraints (primary keys, check constraints, etc.). Check Constraints A CHECK constraint is an expression that must be satisfied by the values of e...Foreign Key Constraints A FOREIGN KEY is a column (or set of columns) that references another table's primary key. Foreign keys check referential integrity, i.e., the referred primary key must exist in the other table upon insertion. CREATE TABLE t1...2 ); Constraint Error: Violates foreign key constraint because key "id: 2" does not exist in the referenced table Foreign keys can be defined on composite primary keys: CREATE TABLE t3 ( id INTEGER , j VARCHAR , PRIMARY KEY ( id , j )); CREATE TABLE... - https://man.mtool.work/duckdb/1.3/sql/statements/create_table.html
- Data Types – DuckDB 9722
- This page is for DuckDB 1.3, which is outdated. Switch to the current version . Search Shortcut cmd + k | ctrl + k Installation Documentation Getting Started Connect Overview Concurrency Data Import Overview Data Sources CSV Files Overview
...3] INTEGER[] MAP A dictionary of multiple named values, each key having the same type and each value having the same type. Keys and values can be any type and can be different types from one another. Rows may have different keys. map([1, 2], ['a', 'b...named values, where each key is a string, but the value can be a different type for each key. Each row must have the same keys. {'i': 42, 'j': 'a'} STRUCT(i INTEGER, j VARCHAR) UNION A union of multiple alternative data types, storing one of them in...different member types of the union. union_value(num := 2) UNION(num INTEGER, text VARCHAR) Rules for Case Sensitivity The keys of MAP s are case-sensitive, while keys of UNION s and STRUCT s are case-insensitive. For examples, see the Rules for Case... - https://man.mtool.work/duckdb/1.3/sql/data_types/overview.html
- Parquet Encryption – DuckDB 9643
- This page is for DuckDB 1.3, which is outdated. Switch to the current version . Search Shortcut cmd + k | ctrl + k Installation Documentation Getting Started Connect Overview Concurrency Data Import Overview Data Sources CSV Files Overview
...on with some limitations . Reading and Writing Encrypted Files Using the PRAGMA add_parquet_key function, named encryption keys of 128, 192, or 256 bits can be added to a session. These keys are stored in-memory: PRAGMA add_parquet_key ( 'key128' , '...er and all columns using the footer_key . The Parquet specification allows encryption of individual columns with different keys, e.g.: COPY tbl TO 'tbl.parquet' ( ENCRYPTION_CONFIG { footer_key : 'key256' , column_keys : { key256 : [ 'col0' , 'col1'...rted at the moment and will cause an error to be thrown (for now): Not implemented Error: Parquet encryption_config column_keys not yet implemented Performance Implications Note that encryption has some performance implications. Without encryption, r... - https://man.mtool.work/duckdb/1.3/data/parquet/encryption.html
- ODBC API on Windows – DuckDB 9372
- This page is for DuckDB 1.3, which is outdated. Switch to the current version . Search Shortcut cmd + k | ctrl + k Installation Documentation Getting Started Connect Overview Concurrency Data Import Overview Data Sources CSV Files Overview
...ith that DSN. More Detailed Windows Setup There are two ways to configure the ODBC driver, either by altering the registry keys as detailed below, or by connecting with SQLDriverConnect . A combination of the two is also possible. Furthermore, the OD...rConnect will take precedence. For the details of the configuration parameters, see the ODBC configuration page . Registry Keys The ODBC setup on Windows is based on registry keys (see Registry Entries for ODBC Components ). The ODBC entries can be p...tested and used the system entries based on HKLM->SOFTWARE->ODBC . The odbc_install.exe changes this entry that has two subkeys: ODBC.INI and ODBCINST.INI . The ODBC.INI is where users usually insert DSN registry entries for the drivers. For example,... - https://man.mtool.work/duckdb/1.3/clients/odbc/windows.html
- Schema – DuckDB 8688
- This page is for DuckDB 1.3, which is outdated. Switch to the current version . Search Shortcut cmd + k | ctrl + k Installation Documentation Getting Started Connect Overview Concurrency Data Import Overview Data Sources CSV Files Overview
...Bestpractice Do not define constraints unless your goal is to ensure data integrity. Microbenchmark: The Effect of Primary Keys We illustrate the effect of using primary keys with the LDBC Comment table at scale factor 300 . This table has approx. 55...461.6 s Load without primary key 121.0 s Load without primary key then add primary key 242.0 s For this data set, primary keys will only have a (small) positive effect on highly selective queries such as when filtering on a single identifier. Defini...ning primary keys (or indexes) will not have an effect on join and aggregation operators. Bestpractice For best bulk load performance, avoid... - https://man.mtool.work/duckdb/1.3/guides/performance/schema.html
- Star Expression – DuckDB 8513
- This page is for DuckDB 1.3, which is outdated. Switch to the current version . Search Shortcut cmd + k | ctrl + k Installation Documentation Getting Started Connect Overview Concurrency Data Import Overview Data Sources CSV Files Overview
..._name . * FROM table_name JOIN other_table_name USING ( id ); Similarly, the * expression can also be used to retrieve all keys from a struct as separate columns. This is particularly useful when a prior operation creates a struct of unknown shape, o...r if a query must handle any potential struct keys. See the STRUCT data type and STRUCT functions pages for more details on working with structs. For example: SELECT st . *...result FROM ( SELECT NULL a , 42 AS b , true AS c ); result 42 STRUCT.* The * expression can also be used to retrieve all keys from a struct as separate columns. This is particularly useful when a prior operation creates a struct of unknown shape, o... - https://man.mtool.work/duckdb/1.3/sql/expressions/star.html
- Hive Partitioning – DuckDB 8338
- This page is for DuckDB 1.3, which is outdated. Switch to the current version . Search Shortcut cmd + k | ctrl + k Installation Documentation Getting Started Connect Overview Concurrency Data Import Overview Data Sources CSV Files Overview
...itioning Hive partitioning is a partitioning strategy that is used to split a table into multiple files based on partition keys . The files are organized into folders. Within each folder, the partition key has a value that is determined by the name o...f the folder. Below is an example of a Hive partitioned file hierarchy. The files are partitioned on two keys ( year and month ). orders ├── year=2021 │ ├── month=1 │ │ ├── file1.parquet │ │ └── file2.parquet │ └── month=2 │ └── fil...e_partitioning flag, the values of the columns will be read from the directories. Filter Pushdown Filters on the partition keys are automatically pushed down into the files. This way the system skips reading files that are not necessary to answer a q... - https://man.mtool.work/duckdb/1.3/data/partitioning/hive_partitioning.html
DuckDB 1.3 Documentation / man.mtool.work