Results of 1 - 10 of about 28 for statistics (0.003 sec.)
- ANALYZE Statement 14895
- The ANALYZE statement recomputes the statistics on DuckDB's tables. Usage The statistics recomputed by the ANALYZE statement are only used for join order optimization . It is therefore recommended to recompute these statistics for improved
...join orders, especially after performing large updates (inserts and/or deletes). To recompute the statistics, run: ANALYZE;... - https://man.mtool.work/duckdb/2.0/sql/statements/analyze.html
- Geometry Data Type 11437
- Name Description GEOMETRY Geospatial entity The GEOMETRY data type is used to store and manipulate geometric objects, such as points, lines, and polygons. The GEOMETRY type was part of the spatial extension but became a built-in data type i
...n DuckDB 1.5. Most of the benefits of having GEOMETRY as a built-in type (e.g., storage optimizations, statistics, etc.) are therefore only available in databases using storage version v1.5 and above. However, almost all of the associat...s'); ---- ┌──────────────┐ │ segment_type │ │ varchar │ ├──────────────┤ │ VALIDITY │ │ DOUBLE │ └──────────────┘ Geometry Statistics GEOMETRY columns contain geometry-specific statistics that track the bounding box of the geometries in each row group, as...well as the set of geometry types and vertex dimensions that are present within the row group. You can inspect the statistics of a column using the stats() function: CREATE TABLE geometries AS SELECT 'POINT Z (30 10 5)'::GEOMETRY AS geom; SELECT st... - https://man.mtool.work/duckdb/2.0/sql/data_types/geometry.html
- File Formats 10323
- Handling Parquet Files DuckDB has advanced support for Parquet files, which includes directly querying Parquet files . When deciding on whether to query these files directly or to first load them to the database, you need to consider severa
...l factors. Reasons for Querying Parquet Files Availability of basic statistics: Parquet files use a columnar storage format and contain basic statistics such as zonemaps . Thanks to these features, Duc...rained, it is worth running the queries directly on Parquet files. Reasons against Querying Parquet Files Lack of advanced statistics: The DuckDB database format has the hyperloglog statistics that Parquet files do not have. These improve the accuracy of c...hat DuckDB produces a suboptimal join order on Parquet files, try loading the Parquet files to DuckDB tables. The improved statistics likely help obtain a better join order. Repeated queries: If you plan to run multiple queries on the same dataset, it is w... - https://man.mtool.work/duckdb/2.0/guides/performance/file_formats.html
- VACUUM Statement 9225
- The VACUUM statement only has basic support in DuckDB and is mostly provided for PostgreSQL-compatibility. Some variants of it, such as when calling for a given column, recompute the distinct statistics (the number of distinct entities) if
...change in the future. Examples No-op: VACUUM; No-op: VACUUM ANALYZE; Calling VACUUM on a given table-column pair rebuilds statistics for the table and column: VACUUM my_table(my_column); VACUUM ANALYZE my_table(my_column); The following operation is not s... - https://man.mtool.work/duckdb/2.0/sql/statements/vacuum.html
- Iceberg Functions 9110
- The iceberg extension provides the following functions: Function Description iceberg_scan(source) Reads an Iceberg table from a path. iceberg_metadata(source) Returns the manifest entries of an Iceberg table. iceberg_snapshots(source) Retur
...ns the snapshots of an Iceberg table. iceberg_column_stats(source) Returns per-data-file, per-column statistics of an Iceberg table. iceberg_partition_stats(source) Returns per-partition-field statistics of an Iceberg table. iceberg_l...pshot_from_id or snapshot_from_timestamp as parameters. iceberg_column_stats The iceberg_column_stats function returns the statistics stored in the manifests for every data file and column. Its columns include file_path , column_name , column_type , lower_...iceberg/lineitem_iceberg', allow_moved_paths = true); iceberg_partition_stats The iceberg_partition_stats function returns statistics per partition field. Its columns include partition_field_name , partition_source_columns , partition_field_transform , low... - https://man.mtool.work/duckdb/2.0/core_extensions/iceberg/iceberg_functions.html
- SUMMARIZE Statement 8766
- The SUMMARIZE statement returns summary statistics for a table, view or a query. Usage SUMMARIZE tbl; To summarize a query, prepend SUMMARIZE to a query. SUMMARIZE SELECT * FROM tbl; See Also For more examples, see the guide on SUMMARIZE .
... - https://man.mtool.work/duckdb/2.0/sql/statements/summarize.html
- COPY Statement 8553
- Examples Read a CSV file into the lineitem table, using auto-detected CSV options: COPY lineitem FROM 'lineitem.csv'; Read a CSV file into the lineitem table, using manually specified CSV options: COPY lineitem FROM 'lineitem.csv' (DELIMITE
...ry.json : COPY (SELECT 42 AS a, 'hello' AS b) TO 'query.json' (FORMAT json, ARRAY true); Return the files and their column statistics that were written as part of the COPY statement: COPY (SELECT l_orderkey, l_comment FROM lineitem) TO 'lineitem_part.parqu...et' (RETURN_STATS); filename count file_size_bytes footer_size_bytes column_statistics partition_keys lineitem_part.parquet 600572 8579141 1445 {'"l_comment"'={column_size_bytes=7642227, max=zzle. slyly, min='...ey"'={column_size_bytes=935457, max=600000, min=1, null_count=0}} NULL Note: for nested columns (e.g., structs) the column statistics are defined for each part. For example, if we have a column name STRUCT(field1 INTEGER, field2 INTEGER) the column statist... - https://man.mtool.work/duckdb/2.0/sql/statements/copy.html
- Friendly SQL 7996
- DuckDB offers several advanced SQL features and syntactic sugar to make SQL queries more concise. We refer to these colloquially as “friendly SQL”. Several of these features were first introduced by DuckDB, while some are inspired by other
...lict, replace the columns of the existing row to the new values of the to-be-inserted row. Describing tables and computing statistics: DESCRIBE : provides a succinct summary of the schema of a table or query. SUMMARIZE : returns summary statistics for a ta... - https://man.mtool.work/duckdb/2.0/sql/dialect/friendly_sql.html
- PostgreSQL Extension Functions 7881
- postgres_clear_cache postgres_configure_pool postgres_execute postgres_hstore_get postgres_hstore_to_json postgres_query read_postgres_binary postgres_clear_cache postgres_clear_cache() -> TABLE Clears cached schema entries (like table name
...specified attached database. It also allows to list the current effective configuration options and the collected runtime statistics of a connection pool. Parameters catalog_name ( VARCHAR ): the name (alias) of the attached Postgres database to which poo...o check that the connection is healthy Examples List the current effective configuration options and the collected runtime statistics of all connections pools (for all attached databases): FROM postgres_configure_pool() Change one or more configuration opt... - https://man.mtool.work/duckdb/2.0/core_extensions/postgres/functions.html
- CREATE VIEW Statement 7881
- The CREATE VIEW statement defines a new view in the catalog. Examples Create a simple view: CREATE VIEW view1 AS SELECT * FROM tbl; Create a view or replace it if a view with that name already exists: CREATE OR REPLACE VIEW view1 AS SELECT
...ists, it is replaced. CREATE SECURE VIEW defines a view that does not leak information about the underlying tables through statistics or query plans. Regular views can expose data that the view query would filter out (for example via stats() ). Secure view... - https://man.mtool.work/duckdb/2.0/sql/statements/create_view.html
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