Results of 1 - 10 of about 11 for rule (0.002 sec.)
- Information Schema 12553
- The views in the information_schema are SQL-standard views that describe the catalog entries of the database. These views can be filtered to obtain information about a specific column or table. DuckDB's implementation is based on PostgreSQL
...ces. VARCHAR 'students_id_pkey' match_option Match option of the foreign key constraint. Always NONE . VARCHAR NONE update_rule Update rule of the foreign key constraint. Always NO ACTION . VARCHAR NO ACTION delete_rule Delete rule of the foreign key... - https://man.mtool.work/duckdb/2.0/sql/meta/information_schema.html
- Numeric Functions 11042
- Numeric Operators The table below shows the available mathematical operators for numeric types . Operator Description Example Result + Addition 2 + 3 5 - Subtraction 2 - 3 -1 * Multiplication 2 * 3 6 / Float division 5 / 2 2.5 // Division 5
.... round_even(v NUMERIC, s INTEGER) Alias of roundbankers(v, s) . Round to s decimal places using the rounding half to even rule . Values s < 0 are allowed. roundbankers(v NUMERIC, s INTEGER) Alias of round_even(v, s) . Round to s decimal places using...the rounding half to even rule . Values s < 0 are allowed. round(v NUMERIC, s INTEGER) Round to s decimal places. Values s < 0 are allowed. setseed(x) Se...UMERIC, s INTEGER) | Description | Alias of roundbankers(v, s) . Round to s decimal places using the rounding half to even rule . Values s < 0 are allowed. | | Example | round_even(24.5, 0) | | Result | 24.0 | roundbankers(v NUMERIC, s INTEGER) | Des... - https://man.mtool.work/duckdb/2.0/sql/functions/numeric.html
- Environment 10740
- The environment where DuckDB is run has an obvious impact on performance. This page focuses on the effects of the hardware configuration and the operating system used. Hardware Configuration CPU DuckDB's officially supported architectures a
...ormance guarantees for these platforms. Memory Bestpractice Aim for 1-4 GB memory per thread. Minimum Required Memory As a rule of thumb, DuckDB requires a minimum of 125 MB of memory per thread. For example, if you use 8 threads, you need at least 1...n when using network-attached disks: If you are writing to disk, it is important that the disks are reliable. As a general rule of thumb, this is true for locally attached disks, and block storage in the cloud. If your workload is larger than memory... - https://man.mtool.work/duckdb/2.0/guides/performance/environment.html
- INSERT Statements 9833
- INSERT statements are the standard way of loading data into a relational database. When using INSERT statements, the values are supplied row-by-row. While simple, there is significant overhead involved in parsing and processing individual I
...ERT statements. This makes lots of individual row-by-row insertions very inefficient for bulk insertion. Bestpractice As a rule-of-thumb, avoid using lots of individual row-by-row INSERT statements when inserting more than a few rows (i.e., avoid usi... - https://man.mtool.work/duckdb/2.0/data/insert.html
- Parquet Tips 8641
- Below is a collection of tips to help when dealing with Parquet files. Tips for Reading Parquet Files Use union_by_name When Loading Files with Different Schemas The union_by_name option can be used to unify the schema of files that have di
...the WHERE clause of the query. However, there is some overhead associated with reading the metadata in each group. A good rule of thumb is to ensure that the number of row groups per file is at least as large as the number of CPU threads used to que... - https://man.mtool.work/duckdb/2.0/data/parquet/tips.html
- Python Function API 7735
- You can create a DuckDB user-defined function (UDF) from a Python function so it can be used in SQL queries. Similarly to regular functions , they need to have a name, a return type and parameter types. Creating Functions To register a Pyth
...a pure function, meaning it will produce the same output when given the same input. If your function does not follow that rule, for example when your function makes use of randomness, then you will need to mark this function as having side_effects .... - https://man.mtool.work/duckdb/2.0/clients/python/function.html
- ODBC Extension 7735
- Please note that DuckDB also offers an ODBC client , which allows you to connect to DuckDB via ODBC from other applications. The odbc_scanner extension allows connecting to other databases (using their ODBC drivers ) and run queries with th
...ing to ODBC specification, connections to remote DB are expected to have auto-commit mode enabled by default. As a general rule, transaction commands BEGIN TRANSACTION / COMMIT / ROLLBACK are not supposed to be sent over ODBC as SQL commands. Doing s... - https://man.mtool.work/duckdb/2.0/core_extensions/odbc/overview.html
- CSV Auto Detection 7735
- When using read_csv , the system tries to automatically infer how to read the CSV file using the CSV sniffer . This step is necessary because CSV files are not self-describing and come in many different dialects. The auto-detection works ro
...ughly as follows: Detect the dialect of the CSV file (delimiter, quoting rule, escape). Detect the types of each of the columns. Detect whether or not the file has a header row. By default the system... - https://man.mtool.work/duckdb/2.0/data/csv/auto_detection.html
- FROM and JOIN Clauses 7432
- The FROM clause specifies the source of the data on which the remainder of the query should operate. Logically, the FROM clause is where the query starts execution. The FROM clause can contain a single table, a combination of multiple table
...join based on how they are written in the join clause. Each result row has the columns from both relations. A join uses a rule to match pairs of rows from each relation. Often this is a predicate, but there are other implied rules that may be specif... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/from.html
- Types 7130
- DuckDB is a strongly typed database system. As such, every column has a single type specified. This type is constant over the entire column. That is to say, a column that is labeled as an INTEGER column will only contain INTEGER values. Duc
...The duckdb_value_is_null function can be used to check if a specific value is NULL or not. The exception to the auto-cast rule is the duckdb_value_varchar_internal function. This function does not auto-cast and only works for VARCHAR columns. The re... - https://man.mtool.work/duckdb/2.0/clients/c/types.html
DuckDB 2.0 Documentation / man.mtool.work