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- ANALYZE Statement – DuckDB 12805
- This page is for DuckDB 1.3, which is outdated.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
...ot Sitemap Live Demo Documentation / SQL / Statements Copy Markdown ANALYZE Statement 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 . I...t 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 ; 関連キーワード statistics statement join recompute Documentation Statements Copy Markdown Statement recomputes DuckDB tables Usage recomputed used o... - https://man.mtool.work/duckdb/1.3/sql/statements/analyze.html
- File Formats – DuckDB 11679
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...load them to the database, you need to consider several 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 data set, it is... - https://man.mtool.work/duckdb/1.3/guides/performance/file_formats.html
- VACUUM Statement – DuckDB 11350
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...rovided for PostgreSQL-compatibility. Some variants of it, such as when calling for a given column, recompute the distinct statistics (the amount if distinct entities) if they have become stale due to updates. Warning The behavior of VACUUM is not consiste...hange 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 ); Rebuild statistics for the table and column: VACUUM ANALYZE my_ta...laim space. For instruction on reclaiming space, refer to the “Reclaiming space” page . Syntax 関連キーワード column table statistics space statement PostgreSQL given distinct Reclaiming Documentation Statements Copy Markdown Statement support DuckDB mostl... - https://man.mtool.work/duckdb/1.3/sql/statements/vacuum.html
- COPY Statement – DuckDB 9738
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...n : 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.pa...rquet' ( 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/1.3/sql/statements/copy.html
- SUMMARIZE Statement – DuckDB 9097
- 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
...temap Live Demo Documentation / SQL / Statements Copy Markdown SUMMARIZE Statement The SUMMARIZE statement returns summary statistics for a table, view or a query. Usage SUMMARIZE tbl ; In order to summarize a query, prepend SUMMARIZE to a query. SUMMARIZE...ples, see the guide on SUMMARIZE . 関連キーワード query Documentation Statements Copy Markdown Statement statement summary statistics table view Usage order summarize prepend Also more examples guide 関連するページ DESCRIBE Statement ANALYZE Statement Summ... - https://man.mtool.work/duckdb/1.3/sql/statements/summarize.html
- Friendly SQL – DuckDB 8300
- 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
...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/1.3/sql/dialect/friendly_sql.html
- Pragmas – DuckDB 7815
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...he disabled_optimizers option allows selectively disabling optimization steps. For example, to disable filter_pushdown and statistics_propagation , run: SET disabled_optimizers = 'filter_pushdown,statistics_propagation' ; The available optimizations can be... - https://man.mtool.work/duckdb/1.3/configuration/pragmas.html
- Join Operations – DuckDB 7815
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.../ Performance Copy Markdown Join Operations How to Force a Join Order DuckDB has a cost-based query optimizer, which uses statistics in the base tables (stored in a DuckDB database or Parquet files) to estimate the cardinality of operations. Turn off the... - https://man.mtool.work/duckdb/1.3/guides/performance/join_operations.html
- Utility Functions – DuckDB 7815
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...he string . sha256(string) Returns a VARCHAR with the SHA-256 hash of the string . stats(expression) Returns a string with statistics about the expression. Expression can be a column, constant, or SQL expression. txid_current() Returns the current transact...esult d7a5c5e0d1d94c32218539e7e47d4ba9c3c7b77d61332fb60d633dde89e473fb stats(expression) Description Returns a string with statistics about the expression. Expression can be a column, constant, or SQL expression. Example stats(5) Result '[Min: 5, Max: 5][H... - https://man.mtool.work/duckdb/1.3/sql/functions/utility.html
- Querying Parquet Metadata – DuckDB 7641
- 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
...query the metadata contained within a Parquet file, which reveals various internal details of the Parquet file such as the statistics of the different columns. This can be useful for figuring out what kind of skipping is possible in Parquet files, or even... - https://man.mtool.work/duckdb/1.3/data/parquet/metadata.html
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