Results of 1 - 10 of about 22 for pushdown (0.002 sec.)
- Table Functions 13955
- The table function API can be used to define a table function that can then be called from within DuckDB in the FROM clause of a query. API Reference Overview duckdb_table_function duckdb_create_table_function (); void duckdb_destroy_table_
...duckdb_table_function table_function , duckdb_table_function_t function ); void duckdb_table_function_supports_projection_pushdown ( duckdb_table_function table_function , bool pushdown ); duckdb_state duckdb_register_table_function ( duckdb_connection...nction ); Parameters table_function : The table function function : The function duckdb_table_function_supports_projection_pushdown Sets whether or not the given table function supports projection pushdown. If this is set to true, the system will provide...e (the default), the system will expect all columns to be projected. Syntax void duckdb_table_function_supports_projection_pushdown ( duckdb_table_function table_function , bool pushdown ); Parameters table_function : The table function pushdown : True i... - https://man.mtool.work/duckdb/2.0/clients/c/table_functions.html
- Metrics 11211
- DuckDB provides a set of metrics that can be used to monitor the performance and health of the database. Metrics are named ⟨group⟩.⟨metric⟩ , e.g., query.total_time or operator.timing . The set of collected metrics is controlled with the tr
...using the duckdb_optimizers() table function : optimizer.expression_rewriter , optimizer.filter_pullup , optimizer.filter_pushdown , optimizer.empty_result_pullup , optimizer.cte_filter_pusher , optimizer.regex_range , optimizer.in_clause , optimizer.jo...ubexpressions , optimizer.common_aggregate , optimizer.column_lifetime , optimizer.build_side_probe_side , optimizer.limit_pushdown , optimizer.top_n , optimizer.compressed_materialization , optimizer.duplicate_groups , optimizer.reorder_filter , optimiz...er.sampling_pushdown , optimizer.join_filter_pushdown , optimizer.extension , optimizer.materialized_cte , optimizer.aggregate_function_rewrite... - https://man.mtool.work/duckdb/2.0/dev/metrics.html
- Delta Extension 10841
- The delta extension adds support for the Delta Lake open-source storage format . It is built using the Delta Kernel . The extension reads Delta tables, local and remote, and writes them: it can create tables and append to them. For implemen
...each transaction reads the latest version; since v1.5.3, it loads only the log entries committed since the previous read. PUSHDOWN_PARTITION_INFO BOOLEAN true Push down partition information so that whole files can be skipped based on partition values....PUSHDOWN_FILTERS VARCHAR all Filter pushdown mode for file skipping. One of none , all , constant_only , dynamic_only . ATTACH 's3://⟨my_bucket⟩/⟨path⟩' AS my_table (...TYPE delta, PIN_SNAPSHOT true, PUSHDOWN_FILTERS 'constant_only' ); Inspecting Scanned Files delta_list_files returns the data files a scan would read for a table,... - https://man.mtool.work/duckdb/2.0/core_extensions/delta.html
- Reading and Writing Parquet Files 9393
- Examples Read a single Parquet file: SELECT * FROM 'test.parquet'; Figure out which columns/types are in a Parquet file: DESCRIBE SELECT * FROM 'test.parquet'; Create a table from a Parquet file: CREATE TABLE test AS SELECT * FROM 'test.par
...may contain NaN values. When set to true, the reader accounts for NaN when using a column's min/max statistics for filter pushdown, since NaN does not compare as ordered. BOOL false encryption_config Configuration for Parquet encryption . STRUCT - filen...plements the file_row_number column, which returns the file-relative row index. Partial Reading DuckDB supports projection pushdown into the Parquet file itself. That is to say, when querying a Parquet file, only the columns required for the query are re...art of the Parquet file that you are interested in. This will be done automatically by DuckDB. DuckDB also supports filter pushdown into the Parquet reader. When you apply a filter to a column that is scanned from a Parquet file, the filter will be pushe... - https://man.mtool.work/duckdb/2.0/data/parquet/overview.html
- Directly Reading Files 9208
- DuckDB allows directly reading files via the read_text and read_blob functions. These functions accept a filename, a list of filenames, or a glob pattern. They output the content of each file as a VARCHAR or BLOB , respectively, along with
...this data (e.g., HTTPFS may not always return a valid timestamp), the cell is set to NULL instead. Support for Projection Pushdown These table functions also use projection pushdown to avoid computing properties unnecessarily. For example, you can glob... - https://man.mtool.work/duckdb/2.0/guides/file_formats/read_file.html
- MySQL Extension 9023
- The mysql extension allows DuckDB to directly read and write data from/to a running MySQL instance. The data can be queried directly from the underlying MySQL database. Data can be loaded from MySQL tables into DuckDB tables, or vice versa.
....0, you can route an entire session to an attached MySQL database with the CONNECT statement . While connected, the remote pushdown optimizer ships queries directly to the MySQL server instead of pulling tables over the wire, and DISCONNECT returns the s...o BOOLEAN true mysql_debug_show_queries DEBUG SETTING: print all queries sent to MySQL to stdout false mysql_enable_filter_pushdown Whether or not to use filter pushdown (without predicate analyzer) true mysql_enable_transactions Whether to run START TRA... - https://man.mtool.work/duckdb/2.0/core_extensions/mysql.html
- PostgreSQL Extension 8652
- The postgres extension allows DuckDB to directly read and write data from a running PostgreSQL database instance. The data can be queried directly from the underlying PostgreSQL database. Data can be loaded from PostgreSQL tables into DuckD
...ou can route an entire session to an attached PostgreSQL database with the CONNECT statement . While connected, the remote pushdown optimizer ships queries directly to the PostgreSQL server instead of pulling tables over the wire, and DISCONNECT returns...er of CPU cores pg_debug_show_queries DEBUG SETTING: print all queries sent to PostgreSQL to stdout false pg_enable_filter_pushdown Whether or not to use filter pushdown true pg_idle_in_transaction_timeout_millis PostgreSQL idle_in_transaction_session_ti... - https://man.mtool.work/duckdb/2.0/core_extensions/postgres/overview.html
- File Formats 8467
- 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
...ic statistics such as zonemaps . Thanks to these features, DuckDB can leverage optimizations such as projection and filter pushdown on Parquet files. Therefore, workloads that combine projection, filtering, and aggregation tend to perform quite well when...derate. Bestpractice The ideal range is between 100 MB and 10 GB per individual Parquet file. Hive Partitioning for Filter Pushdown When querying many files with filter conditions, performance can be improved by using a Hive-format folder structure to pa... - https://man.mtool.work/duckdb/2.0/guides/performance/file_formats.html
- CONNECT and DISCONNECT Statements 8114
- New Support for the CONNECT and DISCONNECT statements was introduced in DuckDB 2.0. The CONNECT statement routes the current session to a remote database, so that subsequent queries execute on that remote and their results stream back. DISC
...execution, including: DuckDB servers reached over the Quack protocol . PostgreSQL and MySQL servers. For these, the remote pushdown optimizer ships SQL directly to the server instead of pulling tables over the wire. In-process local databases, such as th... - https://man.mtool.work/duckdb/2.0/sql/statements/connect.html
- Tuning Workloads 7929
- DuckDB aims to perform well out of the box, so most workloads do not require any tuning. When tuning is worthwhile, there is no single configuration or magic number that is optimal for every workload: the right settings depend on what you a
...ce issues. A few general directions: Avoid nested loop joins in favor of hash joins. A scan that does not include a filter pushdown for a filter condition that is later applied performs unnecessary IO. Try rewriting the query to apply a pushdown. Bad joi... - https://man.mtool.work/duckdb/2.0/guides/performance/how_to_tune_workloads.html
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