Results of 1 - 3 of about 3 for pivoting (0.001 sec.)
- PIVOT Statement 11570
- The PIVOT statement allows distinct values within a column to be separated into their own columns. The values within those new columns are calculated using an aggregate function on the subset of rows that match each distinct value. DuckDB i
...ts both the SQL Standard PIVOT syntax and a simplified PIVOT syntax that automatically detects the columns to create while pivoting. PIVOT_WIDER may also be used in place of the PIVOT keyword. For details on how the PIVOT statement is implemented, see th...he orientation of how the data is displayed without aggregating, use the first aggregate function. In this example, we are pivoting numeric values, but the first function works very well for pivoting out a text column. (This is something that is difficul...ike the simplified syntax, the IN clause must be specified for each column to be pivoted. If you are interested in dynamic pivoting, the simplified syntax is recommended. Note that no commas separate the expressions in the FOR clause, but that value and... - https://man.mtool.work/duckdb/2.0/sql/statements/pivot.html
- Pivot Internals 9301
- PIVOT Pivoting is implemented as a combination of SQL query re-writing and a dedicated PhysicalPivot operator for higher performance. Each PIVOT is implemented as set of aggregations into lists and then the dedicated PhysicalPivot operator
...s those lists into column names and values. Additional pre-processing steps are required if the columns to be created when pivoting are detected dynamically (which occurs when the IN clause is not in use). DuckDB, like most SQL engines, requires that all...es in memory, so you can lower or raise pivot_filter_threshold to trade off time against memory usage. UNPIVOT Internals Unpivoting is implemented entirely as rewrites into SQL queries. Each UNPIVOT is implemented as set of unnest functions, operating on...a list of the column names and a list of the column values. If dynamically unpivoting, the COLUMNS expression is evaluated first to calculate the column list. For example: UNPIVOT monthly_sales ON jan, feb, m... - https://man.mtool.work/duckdb/2.0/internals/pivot.html
- FILTER Clause 7013
- The FILTER clause may optionally follow an aggregate function in a SELECT statement. This will filter the rows of data that are fed into the aggregate function in the same way that a WHERE clause filters rows, but localized to the specific
...ple aggregates with different filters, and when creating a pivoted view of a dataset. FILTER provides a cleaner syntax for pivoting data when compared with the more traditional CASE WHEN approach discussed below. Some aggregate functions also do not filt...can be dynamically generated in a host programming language to leverage DuckDB's SQL engine for rapid, larger than memory pivoting. First generate an example dataset: CREATE TEMP TABLE stacked_data AS SELECT i, CASE WHEN i <= rows * 0.25 THEN 2022 WHEN... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/filter.html
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